ct somatom sessions-33

SOMATOM SessionsAnswers for life in Computed Tomography

SOMATOM Force:Bringing Personalized Medicine to CT

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December 2013 | International Edition Issue 33

Newssyngo.via Frontier – Gateway to an Open Research Environment Page 31

BusinessReady for the Next Revolution in Stroke Care? Page 40

Clinical ResultsCoronary CTA with Reduced Contrast and Radiation Dose of 0.19 mSv Page 50

ScienceRadiation Hygiene – Transparent and Easy Page 72

2 SOMATOM Sessions | December 2013 | www.siemens.com/SOMATOM-Sessions

Editorial

Professor Stefan Schönberg, MD, University Medical Center Mannheim, Germany

Cover page: Dynamic CTA – 64 cm acquired with spiral 4D mode at 80 kV, 110 mAs, with 45 mL contrast. The vascular structures of the complete trunk are clearly demonstrated, and the suspected leaking from the aortic stent could be confidently ruled out. Courtesy of University Medical Center Mannheim, Germany

“In a general population with a very complex age and disease structure, the SOMATOM Force can solve the problems presented by every radiological situation for virtually every patient.”

SOMATOM Sessions | December 2013 | www.siemens.com/SOMATOM-Sessions 3

Editorial

In today’s fast changing global health-care environment, Siemens’ aspiration is to contribute in two major directions. Together with our excellent network of academic partners, we continue to extend the frontiers of available diag-nostic and treatment capabilities. At the same time – and equally important – we innovate to make our technology accessible to more patients around the world.

The cover article in this RSNA 2013 edition of SOMATOM Sessions intro-duces the latest frontier-shifting CT scanner from the Siemens innovation powerhouse. The new Dual Source CT SOMATOM Force* builds on the out-standing clinical success of Siemens’ unique Dual Source technology push-ing current capabilities and opening up new possibilities. SOMATOM Force features enhanced temporal, spatial and contrast resolution and introduces Turbo Flash scanning with up to 730 mm per second z-coverage for free-breathing CT imaging. Its out-standing tube power – already avail-able at 70 kV – makes low kV imaging accessible to virtually all patients and

allows for unmatched iodine contrast enhancement. All this, together with a new level of spectral separation for high precision Dual Energy applica-tions, opens the door to CT examina-tions tailored to specific patient need. SOMATOM Force has the true poten-tial to deliver the right diagnostic pre-cision – at previously impossible low radiation and contrast dose levels. In the cover article, you will sense the excitement about the initial expe-rience of SOMATOM Force at the University Medical Centre Mannheim, Germany.

The established SOMATOM Perspective, on the other hand, is an excellent example of how to leverage a leading technology position to develop a high-performance, affordable routine sys-tem with excellent economics. Origi-nally introduced as a 128- and 64-slice system, the SOMATOM Perspective family has now expanded into the 32- and 16-slice arena*. In the related article, you can see how affordability and full upgradeability within the product family together with high-tech features such as SAFIRE, iTRIM, and Single Source Dual Energy make these scanners a great choice – even for challenging economic environments.

As a complement to our CT system portfolio, we are launching the syngo.via software VA30** with expanded functionality for existing applications as well as new applica-tions, such as syngo.CT Liver Analysis*.

Finally, I would like to thank heartily all the participants in the International Right Dose Image Contest for so many truly wonderful contributions.

Enjoy reading about these and a range of other interesting topics in this issue of SOMATOM Sessions.

Dear Reader,

Walter Maerzendorfer, CEO of the Computed Tomography & Radiation Oncology Business Unit, Imaging and Therapy Systems Division, Siemens Healthcare, Forchheim, Germany

** This product is 510(k) pending. Not available for sale in the U.S.

** The products/features (here mentioned) are not commercially available in all countries. Due to regulatory reasons their future availability cannot be guaranteed. Please contact your local Siemens organization for further details.


December 2013

Contents

News14 Getting Further in CT with New Imaging Possibilities18 Improving Accuracy and Workflow Speed in

Transcatheter Aortic Valve Implantation22 Fighting Aortic Aneurysms with Modern CT

Technology26 Scientifically Validated: New Applications for CARE kV

and Adaptive 4D Spiral28 Back Among the Pioneers31 syngo.via Frontier – Gateway to an Open Research

Environment32 Continuous Commitment to the Right Dose34 Charting New Paths with True Dual Energy36 Open Up New Opportunities with New Configurations38 Getting to Grips with Stress Myocardial Perfusion

Imaging

Business40 Ready for the Next Revolution in Stroke Care?44 All-in-one47 When Space is at a Premium – Compact High Quality

Scanning

Clinical Results Cardiovascular48 Myocardial Ischemia Assessment using

Adenosine-Stress Dynamic Myocardial CT Perfusion50 Coronary CTA with Reduced Contrast and Radiation

Dose of 0.19 mSv52 Bicuspid Aortic Valve with Anomalous Coronary

Artery Fistula – A Rare Incidental Coincidence

Neurology54 Dynamic Volume Perfusion CT in a Case of

Childhood Moyamoya Disease before and after Surgical Revascularization

56 Differentiating an Intracranial Hemorrhage from Iodine in Acute Stroke after Intra-arterial Recanalization

Acute Care58 Diagnosis of Splenic Rupture in an 11-year-old Girl

using a Sliding Gantry CT

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SOMATOM Force: Bringing Personalized Medicine to CT


1814 32 72

Pulmonology60 Automated Quantification of Pulmonary Perfused

Blood Volume in Acute Pulmonary Embolism using Dual Energy CTPA

Urology62 Diagnosing Small Renal Calculi using Low Dose

Dual Energy CT at 0.8 mSv64 Differentiating Stent from Stone: A New Approach

using Dual Energy CT

Pediatrics66 Diagnosing Tracheal Stenosis in a 10-week-old Baby

without Sedation

Science68 Image Quality in Computed Tomography72 Radiation Hygiene – Transparent and Easy74 Radiation Protection Scientifically Proven for

Routine Practice

Customer Excellence76 Tips & Tricks: Easy Bone and Vessel Isolation77 Clinical Workshops 201478 Upcoming Events & Congresses 2013/201479 Free DVD of the 11th SOMATOM World Summit

in Orlando80 Twenty Years of STAR – A Successful Educational

Program for Radiologists81 From Print to App: SOMATOM Sessions for Everyone81 2014 Multislice CT Symposium in Garmisch

82 Subscriptions83 Imprint

Contents


Cover Story

Curtain up on Siemens’ latest accom-plishment in outstanding engineering: The new SOMATOM Force CT scanner – the lead Dual Source scanner now in the market, re-writes the way CT will be used in the future for diagno-

sis and treatment decisions. The premiere takes place at the German University Medical Center Mann-heim, where the Institute of Clinical Radiology is proud to be the very first research institution worldwide to

By Irène Dietschi

A quantum leap in CT engineering: Siemens’ new scanner, the SOMATOM® Force, takes over the lead in the Dual Source CT portfolio. As such it will enable radiologists not only to perform even more individualized diagnostics, but also to contribute to personalized medicine and new therapy concepts. Interdisci-plinary imaging experts at the University Medical Center Mannheim, Germany, share their experience of the first SOMATOM Force installed worldwide.

SOMATOM Force: Bringing Personalized Medicine to CT

install the new CT system. The inter-disciplinary Mannheim specialists were excited to start working and doing translational research with their new scanner, not only because the SOMATOM Force is almost twice as

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High resolution stent imaging – coronary CTA images acquired with Turbo Flash mode in only 0.18 s, at 70 kV and pitch 3.2, with 0.43 mSv. The patient’s heart rate varied between 58 to 70 bmp during the examination. The VRT image (Fig. 1A) shows nicely two long stents in both LAD and Cx. The curved MPR image (Fig. 1B) shows the details in the LAD stent.

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Cover Story

The Institute of Clinical Radiology at the University Medical Center in Mannheim, Germany, is the very first place worldwide to install the new SOMATOM Force (Associate Professor Thomas Henzler, MD, left, Professor Stefan Schönberg, MD, right, patient, middle).

fast, more precise, and even more patient friendly than any of its prede-cessors, but also because they believe that it is possibly a vehicle for a new medical paradigm. “From now on, imaging is no longer limited to classi-cal diagnostics,” says Professor Stefan Schönberg, MD, director of the hospi-tal, and he explains: “As radiologists, we now have the possibility to create value-based medicine by targeting the clinical endpoint of medical proce-dures: the recovery of the patient.”

CT is the imaging technique that in comparison with MRI or PET, delivers the most robust data in the long run, adds Professor Lothar Schad, PhD, director of computer-assisted clinical medicine at the faculty. “The consis-tency of quantitative data that we are able to produce using the high-end CT device cannot be equalled using any other imaging system,” he says. Schad thinks that CT will become more and

more accepted as an imaging bio-marker, which will set the benchmark for other imaging techniques.

The Medical Faculty Mannheim, part of Heidelberg University, has been focusing on medical technology for over a decade, according to the facul-ty’s dean Professor Uwe Bicker, MD, PhD. The renowned University Medical Center is located near the center of the city, on a campus designed for translational clinical research. The immediate proximity between the hospital, patients, and research is regarded as a huge advantage by the dean: Mannheim was successful in the national competition for the so-called research campus, funded by the German Ministry of Education and Research, which in Mannheim involves a public private partnership with Siemens.

In this context, dean Uwe Bicker also points out some of the limits of tech-

nological progress: “Technology by itself is useless unless its application is affordable for healthcare providers,” he says. In his opinion, this equation is one of the most challenging for the future.

So, how does the SOMATOM Force contribute to solving this challenge? It does so in the first place with a number of engineering milestones, which are believed to change behav-ior patterns in CT imaging. Schönberg is enthusiastic: “In a general popula-tion with a very complex age and disease structure, this new scanner can solve the problems presented by every radiological situation for virtu-ally every patient,” he says. Associate Professor Thomas Henzler, MD, head of cardio-thoracic imaging at the Insti-tute of Clinical Radiology, is equally excited. He is convinced that “With the SOMATOM Force we have elimi-nated almost all contraindications for


CT. The scanner allows precise and individualized imaging of all patients and thus changes our thinking of CT completely.” In his and Schönberg’s view the new system is especially promising in individualized diagnos-tics: Every patient should have his or

her best possible diagnostic proce-dure, meaning that “the CT scan of an 85-year-old woman, weighing 60 kilograms, has in terms of parameter settings little in common with that of a 40-year-old morbidly obese man with a BMI of 40 as far as required

dose are concerned. Only this high-end CT system is capable of offering the variety of parameters for such an individualized approach.”

Individualized diagnostics is related to precision medicine. In the future, imaging will contribute substantially to the response evaluation of certain therapies, for example for cancer patients. Large nations are revising their healthcare policies radically in this respect: Henceforth, it will increas-ingly depend on the response rate – the ‘endpoints’, as Schönberg puts it – whether medical treatment will be reimbursed or not. In such an environ-ment, novel high-end systems such as the SOMATOM Force are fundamental for precise and sound decision-making by provision of quantitative data.

The SOMATOM Force is expected to lead to positive changes in a number of areas. First of all, it is two steps ahead in contrast-to-noise.

Low-kV imaging for all patients

The engineers have put huge effort into lowering the tube voltage, while maintaining very high photon flux at a very small focal spot. Low kV exams are no longer only possible for small children and slim adults, but will be possible for practically all adults and even obese patients from now on. This, as a matter of routine, results in a reduction in radiation dose, and more: With the SOMATOM Force, the contrast-to-noise ratio has been

Associate Professor Thomas Henzler, MD, University Medical Center Mannheim, Germany

“With the SOMATOM Force we have elimi-nated almost all contraindications for CT. The scanner allows precise and individu-alized imaging of all patients and thus changes our thinking of CT completely.”

The immediate proximity between hospital, patients, and research is regarded as a huge advantage by dean Professor Uwe Bicker, MD, PhD: University Medical Center Mannheim was successful in the national competition for the so called research campus, funded by the German Ministery of Educa-tion and Research, which in Mannheim involves a public private partnership with Siemens. Bicker is very proud of the reputation and the amount of expertise that has been accumulated at the campus lately, especially in imaging. He is reassured by research student Sonja Sudarski who considers Mannheim to be “invaluable for young researchers with a vision,” especially as the medical faculty is equipped with the latest technology.

Cover Story


Cover Story

“As radiologists, we now have the possibility to create value-based

medicine by targeting the clinical endpoint of medical procedures:

the recovery of the patient.”

Professor Stefan Schönberg, MD, University Medical Center Mannheim, Germany

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Low dose for challenging patient – 63 cm acquired with Turbo Flash mode in only 1.2 s, at 80 kV and pitch 2.4, with 1.9 mSv. The image quality is excellent although the patient’s left arm had to be kept in the scan field of view.

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Dual Energy lung PBV – 32 cm acquired in only 4 s, with 55 mL contrast, at 90 / Sn 150 kV. An wedge shaped perfusion defect area is depicted in the left upper lobe, although no pulmonary emboli is present. The image quality is excellent due to greater spectrum separation.

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improved to such an extent that a scan can be done with much lower con-trast medium amounts than previously. Whereas the average CT scanner requires between 90 and 110 milliliters for a certain application, the SOMATOM Force will produce the same image quality with just a fraction of the con-trast medium dose. For a thoracic CT, for example, volumes as low as 25 to 35 milliliters are expected.

This aspect is especially important with regard to kidney protection, as Henzler explains: “In radiology, we’ve been discussing CT doses for years, even though we’ve known that nephro- pathy induced by iodinated contrast is the greater problem with some people undergoing computed tomog-raphy.” Up to 20 percent of patients, especially if they are older and suffer-ing from chronic diseases such as

diabetes, might have to undergo pro-longed pre- and after-care because the contrast agent may harm their kidneys. With the new scanner, this time and cost intensive procedures might no longer be necessary. In short: SOMATOM Force is a versatile scanner. “We are expecting to be able to examine all patients adequately, even those suffering from renal insufficiency,” says Henzler.


Cover Story

Dynamic CTA – 64 cm acquired with spiral 4D mode at 80 kV, 110 mAs, with 45 mL contrast. The vascular structures of the complete trunk are clearly demonstrated, and the suspected leaking from the aortic stent could be confidently ruled out.

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Lowest dose for early detection of lung and colon diseases

For lung and colon scans, the contrast-to-noise ratio is also expected to rise significantly. Why? The SOMATOM Force has further developed the pop-

ular Flash Spiral mode into the new ‘Turbo Flash mode’: Besides being almost twice as fast, it now uses two selective photon shields instead of one. The two tin filters optimize the X-ray spectrum to boost contrast between soft tissue and air in patient scans. The resulting increase in the

contrast-to-noise ratio can be ‘rein-vested’ in lowering the dose, allowing a reduction of approximately 30 per-cent compared with other high-end CT’s.

What this means for clinical practice is explained by Schönberg: “Computed tomography could very well become an important tool for the early detec-tion of lung cancer. The radiation dose for the risk evaluation of bronchial car-cinoma has dropped to an extent that dose is no longer an issue compared with the added value which you create with this exam.”

Moreover, the ‘Turbo Flash mode’ might not only reveal lung lesions, but could also be used for the exclusion or early detection of two other major diseases: coronary heart disease and susceptibility to stroke. As for the detection of colon diseases, studies have produced excellent evidence in support of colon CT. “The results have shown that colon CT is almost equal to classical coloscopy, indicating that it could at least be applied in cases where classical coloscopy is not possible,” Schönberg says.

The SOMATOM Force is not only characterized by low doses, new con-trasts, and reduced need for contrast medium, but also by speed. Compared with its predecessors, it moves breath-takingly fast.

Free breathing for all patients

One problem frequently found in con-ventional scans is motion artifacts, often resulting in insufficient image quality. Studies show that in cases of pneumonia, for example, a significant number of scans carried out with a standard system are unsatisfactory due to blurring. This leads to readmissions that could otherwise have been pre-vented. If doctors ask their colleagues in the radiology department to redo a scan, in one of three cases the reason is impaired image quality. The new SOMATOM Force and its novel Turbo Flash mode can help to minimize this problem: Compared with the former Flash Spiral scan mode, Turbo Flash is almost twice as fast, scanning at 737 mm/s. This means that the Turbo Flash mode literally freezes respira-tion, or other motion induced by the


Cover Story

Whole liver perfusion – 22 cm acquired at 80 kV, 100 mAs, with 17.58 mSv only, for an obese patient (118 kg) with liver tumor.

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diaphragm or the bowel. So, free breathing no longer impedes image quality.

This is a relief, for instance, for older or maybe overweight patients who have trouble holding their breath. It is also relevant for trauma patients who are in considerable pain and/or unconscious, and in pediatric CT where doctors can now perform a CT exam without the need for sedation or controlled breath-ing in children. Finally, speed is a crucial factor in cardiac CT. “So far we have been able to perform a cardiac CT far below 1 mSv in patients whose heart rate was below 65,” says Henzler. “With the new system we will move to a situation in which we can examine higher heart rates and still remain below 1 mSv, acquiring robust results we haven’t seen before.” Henzler

believes that those facts will also generate ‘clinical value’: Cardiac CT will be more consistently integrated in the workflow of the emergency room as an algorithm for patients with intermediate cardiac risk.

Larger field of view

With the SOMATOM Force, Siemens engineers have extended the field of view of the Flash Spiral mode to up to 50 centimeters. They accom-plished this major improvement by introducing the new powerful VECTRON tube which evolved from technology initially introduced with the renowned STRATON tube, and with the StellarInfinity detector. Based on the innovative Stellar technology, the new detector now additionally enhances resolution by 25%, and more-over extends the former z-coverage

by 50%. The combination of two VECTRON tubes and two StellarInfinity detectors in a Dual Source CT enable the realizing of the unique Turbo Flash mode. Henzler is intrigued by this masterpiece of engineering and innovation. “The geometry of the detector has been changed in an ingenious way that we haven’t seen so far in computed tomography,” he says. “We will be able to show even the smallest vessels such as the coro-nary arteries or calcified lesions in perfect resolution, without having to worry about the dose or motion artifacts.” Moreover, the extended field of view will enable radiologists to scan practically all patients in Turbo Flash scan mode, including obese adults as well as patients with kidney disease. With the SOMATOM Force it is expected that the Turbo


Cover Story

Flash mode will become standard, establishing ultra-high pitch scanning as the true successor of conventional spiral modes.

Finally, the SOMATOM Force is likely to become the diagnostic CT tool of choice for personalized medicine: It offers precision CT at its best and is therefore two steps ahead in func-tional analysis and decision making.

Dynamic perfusion at half the dose

Although MRI will probably remain the benchmark for functional imaging, CT is gaining ground very fast. “CT has unmatched advantages if you need imaging in large quantities and within time limits,” Schönberg says.

The SOMATOM Force offers dynamic perfusion – which usually requires high radiation doses – at up to half the dose compared with conventional state-of-the-art CT’s, e.g. for the per-fusion of the liver. The engineering solution lies in the new StellarInfinity detector (with TrueSignal technology plus its 50 percent wider coverage) and the redesign of the Adaptive Dose Shield, already known from the SOMATOM Definition Flash scanner. Matching the scan speed of the SOMATOM Force, the collimator blades can be opened and closed at twice the speed.

Clinical application is possible for various organs, such as pancreas, abdomen, kidneys or the liver. Dynamic perfusion of the liver, for

example, which at present requires doses between 60 and 70 mSv, is expected to be possible at the dose of a conventional 4-phase liver protocol. Why does this make sense? “Think of Bevacizumab,” says Henzler: “On the one hand, Bevacizumab is an impres-sive drug which suppresses angiogenesis in various cancers, including colorectal, lung or kidney. However, it is a costly drug. If you want to know whether patients are responding to the treatment, one way is to monitor these patients with repetitive perfu-sion CT.” Short-term monitoring can reveal which patients respond to anti-angiogenesis treatment, and which patients do not. Long-term CT moni-toring with functional parameters may help to detect recurrence.

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Dynamic Runoff – 61 cm acquired with spiral 4D mode at 70 kV, 130 mAs, with 1.39 mSv and 45 mL contrast. MIP images show nicely the dynamic flow of the vascular details, and additionally, the tendons as well.

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Further Information

www.siemens.com/ SOMATOM-Force

Irène Dietschi is an award-winning Swiss science and medical writer. She writes for the public media, such as the Neue Züricher Zeitung and has published several books.

The product is pending 510(k) clearance, and is not yet commercially available in the United States.

The statements by Siemens customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical” hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.

At the University Medical Center in Mannheim, the medical faculty has defined three fundamental topics it wants to pursue with the SOMATOM Force in various clinical studies: treatment response, nephroproctection and motion artifact reduction. From left to right: Professor Stefan Schönberg, MD, director of Radiology and Nuclear Medicine, Professor Lothar Schad, PhD, director of computer- assisted clinical medicine, Florian Lietzmann, MD, team leader of CT physics research at the institute of computer-assisted clinical medicine, Thomas Henzler, MD, head of cardio-thoracic imaging.

In other tumors such as gastrointestinal stromal tumors, the most promising way to assess treatment response is Dual Energy. In various studies conducted in Mannheim, iodine-related attenua-tion has proven to be a very robust response parameter, as Thomas Henzler explains. Whereas the Dual Energy scanners of the first generation had certain limits in coverage, the new scanner increases energy separation by 30 percent. “We expect that the SOMATOM Force will produce a clear-cut improvement because of the spectral upgrade,” says Henzler. In his view, Dual Energy is clearly gaining ground: Many vascular questions can be answered spectrally in post process-ing, because the two energies have been separated so effectively.

In Mannheim, the medical faculty has defined three major topics that it wants to pursue with the SOMATOM Force in various clinical studies: treatment response, nephroprotec-tion, and motion artifact reduction. Researchers believe that the new standing of computed tomography could affect the workflow of a clinic substantially: CT could evolve into an all-in-one triage for new diagnostics and therapy models. One field in which this progress is already begin-ning to emerge is cardiology and the treatment of acute coronary syn-drome: At the University Medical Center Mannheim, if a patient at risk shows no relevant stenosis of the coronary arteries in cardiac CT, he or she is automatically excluded from

cardiac catheter examination. “With this we have achieved three goals,” Schönberg explains: “First, we have supported our colleagues in cardiol-ogy in their daily work by making sure that catheter exams are conducted with higher therapeutic yield; second, we are more cost-effective; third, we’ve enriched the interventional scope of cardiology by referring to our colleagues those patients who actu-ally need an intervention.” Analysis of this new workflow modality has shown that it is actually cost effec-tive. In the view of dean Uwe Bicker, this is the key factor for any techno-logical innovation: If it is cost effec-tive, it will prove itself on the market.

CT for cardiovascular issues is a role model for interdisciplinary workflow and decision making. But the other important domain that he and his radiology group are aiming for is oncology. Schönberg believes that cancer is the future market for the high-end CT system SOMATOM Force. “My vision is that in five years from now, oncologists around the world will prescribe innovative molecular substances based on functional imag-ing. “If you have to attend to millions of people globally, you need an efficient imaging system in order to apply those substances cost-effec-tively. And this will most likely be CT.”

Cover Story


Comprehensive evaluation of myocardial perfusion with syngo.CT Cardiac Function – Enhancement.

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rendered more flexible, too, as phy-sicians can view images on mobile devices. Sharing findings with col-leagues is also easier for fast and reliable clinical decisions. syngo.via software guides users through the entire workflow, identifying human anatomy, and enabling radiologists to deliver reliable and meaningful quan-titative results. Therefore, syngo.via VA30 is designed to meet as many clinical challenges as possible.

all modalities, managing both day-to-day and more challenging cases suc-cessfully. For this reason, the software must be based on concepts that are efficient, flexible, and intelligent. Auto-mated pre-fetching of prior examina-tions and pre-processing saves valuable time, allowing physicians, technicians and IT professionals to focus on their core patient-centric tasks. Modular licensing models offer flexibility so that the system can grow in line with needs and budget. Workflows are

Every year, clinical routine is becom-ing more and more demanding. Phy-sicians and clinical staff need to make best use of diagnostic technology tools available at their particular medical institution. It is essential to their job to understand diseases more comprehen-sively and make the right treatment decisions faster. This requires technol-ogy providers to continuously innovate medical imaging equipment. Siemens’ syngo.via software is designed to fur-thermore accelerate workflow across

Siemens continues to improve its advanced visualization platform syngo.via for CT: Combined with continuous scanner innovations, Siemens’ syngo.via VA30* offers a range of additional options for diagnosis and pre-procedural planning.

Automatic completion of manufacturer-specific AAA graft order forms with syngo.CT Rapid Stent Planning**.

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By Arjen Bogaards, PhD, Jochen Dormeier, MD, Susanne Hölzer, Dominik Panwinkler, Philip Stenner, PhD

Computed Tomography, Siemens Healthcare, Forchheim, Germany

Getting Further in CT with New Imaging Possibilities

News


syngo.CT Bone Reading enriched by Spine CAD.

4syngo.CT Liver Analysis**: In-depth analysis of liver vascularization combined with surgery planning.

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Automated AAA stent planning

Pre-procedural planning for the treat-ment of an abdominal or thoracic aortic aneurysm requires a precise assessment of several anatomical parameters. Numerous vendors offer stent grafts, each of which requires its own set of measurements. Anatomical assessment and completion of the graft order forms can be tedious and time-consuming. The new syngo.CT Rapid Stent Planning** introduces automatic completion of manufacturer-specific stent order forms. That holds out the prospect of skipping all the cumber-some steps and streamlining abdomi-nal aortic stent planning. It represents an ideal extension to the Rapid Results Technology: Dedicated protocols guide the user through all length and dia-meter measurements, which are then automatically stored in the correspond-ing order form. For delivery purposes, syngo.CT Rapid Stent Planning** pro-vides three order forms as PDFs: Gore Excluder, Zenith Flex, and Medtronic Endurant. Furthermore, new order form templates can be generated to

match the specific requirements of other vendors.1

Comprehensive myocardial perfusion analysis

Coronary CTA is a well-established method of ruling out coronary artery stenosis. Often, an intermediate ste-nosis is found whose hemodynamic relevance may be unclear. In such cases, a myocardial stress perfusion exami-nation can help to decide whether a patient should undergo PCI2 or not. As a “one-stop shop”, CT is becoming increasingly important in the assess-ment of myocardial perfusion. Differ-ent approaches are currently available, but Siemens is the only manufacturer to offer the full spectrum of myocardial perfusion analysis: Whether simple first-pass enhancement, Dual Energy perfusion scanning, or quantitative dynamic myocardial perfusion. With syngo.via VA30 and the new perfu-sion evaluation feature in syngo.CT Cardiac Function-Enhancement, it is now possible to evaluate comprehen-sively all types of myocardial perfusion. Rather than simply looking at a first-pass enhancement scan, the quantifi-

cation of iodine concentration in the myocardium and inspection of quan-titative blood flow and volume data provide additional clinical benefits.3 The visualization in AHA-compliant 17-segment polar maps and the direct overlay in MPR segments help to pinpoint the perfusion defect. With syngo.via VA30, the evaluation of myocardial perfusion becomes faster, easier, and more reliable.

Advanced oncological analysis

Assessment of tumor perfusion in follow-up examinations allows iden-tification of tumor viability before changes in tumor sizes are visible. Identifying these changes at an early stage of oncological treatment adds supplementary clinical information especially when following up on state-of-the-art treatment with anti-angiogenic drugs. The “body perfu-sion” functionality is now available in syngo.via and provides quantification of blood flow, blood volume, and per-meability, combined with automated motion correction for improved ana-tomical alignment. In addition to its

1 Adobe Acrobat Professional required; 2 PCI: Percutaneous coronary intervention; 3 CT DE Heart PBV and/or syngo VPCT Body-Myocardium required

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use in oncology, a further clinical application is to assess perfusion in cases of organ transplantation.

The new syngo.CT Liver Analysis** delivers in-depth clinical insights based on comprehensive analysis of CT data-sets and tools for surgery planning. For the surgeon it is crucial to know the precise size and location of tumors before the operation. It is also essen-tial to assess the amount of liver tissue that is to be resected and the exact anatomical vascular supply to the affected liver segments. By dissecting the liver virtually using the software, the physician is able to compare the amount of resected and residual liver tissue – one of the key factors in the surgery outcome. syngo.CT Liver Analysis** supports these pre-opera-tive planning steps by combining tailored functions and tools with intu-itive workflow guidance.

Extended bone reading support

Building on the success of syngo.CT Bone Reading, the application has been enhanced with CAD* (Computer

Aided Detection) functions to identify suspicious spine lesions. Intended for use as a second reader tool after the initial read has been completed, this supplementary tool draws the radiol-ogists attention to regions of interest (ROI) that may have been initially overlooked. In addition to the revolu-tionary new visualization in bone read-ing – which adapts complex anatomies to reading needs – this new feature has demonstrated potential in detect-ing lytic and blastic metastasis as reported in a scientific publication from the Department of Radiology, University Hospital Erlangen.[1]

With these new additions, syngo.via VA30 offers a comprehensive portfolio enabling holistic oncological reading.

CT imaging – the cornerstone of stroke care

Across the globe, 1 in 6 people will suffer a stroke at some point in their life. It is one of the world’s most threat-ening diseases. Almost two million brain cells could be lost every minute if a stroke patient is left untreated. Fast treatment is essential to improve

the chances of a good outcome. How-ever, the time it takes from the stroke patient arriving in the emergency department to receiving thrombolytic drugs (door-to-needle times) remains a major challenge in many hospitals.

An important element in this cascade of events is the imaging software that is connected to the CT scanner. It is decisive to increase speed and confi-dence of the diagnosis and conse-quently for the implementation and monitoring of effective treatment.

Generally, a non-contrast CT scan and single phase CT Angiography will be administered to exclude bleeding and confirm the presence of an occlu-sion in order to determine eligibility for thrombolytic drug administration. syngo.CT Neuro Perfusion can help to visualize the size of the core infarct and penumbra; the latter represents tissues that may be salvaged through further reperfusion therapy.

Excitingly, 4D CT Angiography is used increasingly and several novel applications are beginning to emerge. syngo.CT Dynamic Angio can create

Assessment of diffuse tumor infiltrations with syngo.CT DE Bone Marrow**.

6View of the neurovasculature from arch to vertex with syngo.CT Neuro DSA.

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News


movies that visualize the flow of con-trast from arterial to venous phase and depict tMIPs. This can help the clini-cian better assess the collateral status and define the occlusion length in stroke.[3] As such, 4D CT Angiography has potential in helping to select the patient optimally suited for interven-tional clot retrieval. All indications at the present suggest that CT imaging will remain the cornerstone of stroke care.

New boost for Dual Energy CT with syngo.via VA30

True Dual Energy offers extended diagnostic possibilities taking CT imag-ing beyond morphology by enabling exploration of functional and quanti-tative aspects. And progress still continues.

A highlight of the syngo.via VA30 is the new Dual Energy application syngo.CT DE Bone Marrow**. The bone marrow can be affected by various pathologies, such as bone bruises after trauma as well as by diffuse tumor infiltrations. Until today, the major modality for imaging these patholo-gies has been MRI. With the benefit of True Dual Energy, CT imaging can now also aid in the diagnosis. syngo.CT DE Bone Marrow** allows for the seg-mentation and the visualization (color-coding) of the bone marrow based on a material decomposition into bone marrow and calcium. This application can be used for both Dual Source and Single Source Dual Energy datasets.

Furthermore the syngo.CT DE Virtual Unenhanced* application has been complemented in order to address a wider clinical spectrum. While the well-established Liver VNC algorithm enables quantification of the iodine uptake in the liver tissue, the new Vir-tual Unenhanced algorithm has been improved for optimized visualization of those organs that – in contrast to the liver – do not contain variable amounts of fat, such as the lung, kid-ney, and pancreas. The iodine uptake may give additional indications about the malignancy of a lesion. Moreover, the effectiveness of a therapy can be validated by evaluating the develop-ment of the iodine uptake in the treated lesion before and after treatment.

Monoenergetic imaging has become a reliable application to improve image quality as well as for effectively reducing metal artifacts. syngo.via VA30 together with syngo.CT DE Mono- energetic Plus** offers a new, power-ful algorithm allowing for a better quantitative assessment of different tissues and lesions by displaying multiple monoenergetic ROIs and the associated absorption curves. A further benefit for research and diagnostic tasks is the ability to export the statis-tical information to the file system for more in-depth evaluation.

syngo.via VA30 offers a broader range of tools to meet today’s grow-ing clinical requirements with the support of high quality CT imaging.

Evaluation of multiple monoenergetic ROIs with syngo.CT DE Monoenergetic Plus**.7

References[1] Automatic detection of lytic and blastic

thoracolumbar spine metastases on computed tomography. Hammon M. et al; Eur Radiol. 2013 July; 23(7): 1862–1870.

[2] Meretoja A et al. Reducing in-hospital delay to 20 minutes in stroke throm-bolysis. Neurology. 2012, 79:306-13.

[3] Frölich AM et al. 4D CT Angiography More Closely Defines Intracranial Thrombus Burden Than Single-Phase CT Angiography. AJNR Am J Neuroradiol. Published online before print April 25, 2013.

Further Information

www.siemens.com/ct-clinical-engines

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Further steps will follow opening up to users the opportunity to fully exploit their diagnostic technology.

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syngo.via can be used as a standalone device or together with a variety of syngo.via-based software options, which are medical devices in their own right.

Not for diagnostic use.

** The products/features (here mentioned) are not commercially available in all countries. Due to regulatory reasons their future availability cannot be guaranteed. Please contact your local Siemens organization for further details.



selected. Choosing a prosthesis that is too small can lead to a paravalvular leak, for example, while fitting one that is too large could cause a catastrophic rupture of the aortic root. In addition, the catheters used in the procedure are relatively large, so physicians must be able to reliably assess calcifications,

ment.[1] However, careful planning of this advanced procedure which is necessary for optimal patient outcome can present a number of challenges for physicians.

Exact measurements of the anatomy of the heart are necessary so that the appropriate sized prosthesis is

Transcatheter aortic valve implanta-tion (TAVI, also known as transcatheter aortic valve replacement (TAVR) in the U.S.) has been shown to signifi-cantly prolong the lives of those severe aortic valvular stenosis patients, who – because of comorbidities – are not candidates for surgical valve replace-

Computed tomography provides valuable information for the planning of transcatheter aortic valve implantation, and the syngo.CT Cardiac Function – Valve Pilot application of syngo.via speeds up workflow while increasing accuracy and safety for patients.

By Sameh Fahmy, MS

syngo.CT Cardiac Function – Valve Pilot: physicians are able to work with zero-delay for quantitative assessment of the aortic annulus.

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Improving Accuracy and Workflow Speed in Transcatheter Aortic Valve Implantation


stenoses, and the diameter of the peripheral arteries, in order to select a suitable access route and avoid potentially fatal complications.

Despite these challenges, physicians such as Professor U. Joseph Schoepf, MD and Professor Stephan Achenbach, MD are able to plan the TAVI procedure efficiently, accurately, and with confi-dence. Joseph Schöpf is Professor of Radiology and Medicine and Director of CT Research and Development at the Medical University of South Carolina in the United States. Stephan Achenbach is Chairman of the Department of Car-diology at the University of Erlangen-Nürnberg in Germany. They both were among the first to test the application syngo.CT Cardiac Function – Valve Pilot.

The software provides a dedicated workflow for CT TAVI planning; auto-matically measuring the dimensions of the aortic annulus providing single-click localization and quantification of the smallest iliac diameter, and auto-matically calculating the corresponding C-arm angulation for a given projection.

Professor Stephan Achenbach, MD, Department of Cardiology, University of Erlangen-Nürnberg

“It enhances our workflow efficiency, which is an aspect that is becoming increasingly significant – especially in centers with extremely high vol-umes,” Schoepf says. “What is more important for me is that it enhances accuracy and safety for patients.”

Assessing critical structures easily

Worldwide, an estimated 40,000 patients have received TAVI.[2] The landmark, multicenter trial PARTNER (Placement of AoRTic TraNscathetER Valve) demonstrated that the TAVI procedure reduced all-cause mortal-ity by nearly 50% in patients who were ineligible for the open proce-dure.[1] Furthermore, key secondary end points, such as patient condition, had significantly improved by the time of the one-year follow up. In the group of patients who were defined as having a high surgical risk, TAVI was found to be non-inferior to surgi-cal aortic valve implantation. Mortal-ity rates after one year were 24.2% for TAVI, compared with 26.8% for the surgical procedure.[3]

While the clinical trials that led to the introduction of the TAVI procedure used echocardiography and conven-tional angiography for pre-procedural planning, Achenbach stresses that CT provides the information that improves the safety and accuracy of the proce-dure. “The question of whether there are arteries of the body, especially in the legs, available to use for an access route can, by far, be best answered by CT,” Achenbach says. “And we now have data that clearly show that CT is the best tool for choosing the correct size of prosthesis.”

The manual detection and measure-ment of the annulus – the structure demarcated by the hinges of the aortic valve leaflets – is a particularly cumbersome and time-consuming process, but one at which the soft-ware excels. As the case is opened, it displays the annular plane and calcu-lates critical measures, such as the area, and long and short axes of the annulus. The ostium views help to determine the distance between the coronary ostia and the annulus plane. A process that could otherwise take

“CT adds tremendously to the TAVI procedure by

making it safer.”

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up to approximately 20 minutes now happens almost instantaneously, and with an unparalleled level of reproducibility.

In a study presented at the 2012 annual meeting of the Radiological Society of North America, Schoepf and his colleagues found that the software was in excellent agreement with human observers.[4] He adds that even in cases where manual adjustments are necessary, the use of the software still saves time by giving radiologists a good starting point from which they can work.

“These sorts of measurements are crucial going into the procedure, but they’re also where substantial human error can occur – with pretty dire consequences,” Schoepf says. “The beauty of having a computer algo-rithm to do it is that if you give it the

same task twice, it comes up with the same measure.”

Choosing the appropriate prosthesis is a balancing act for physicians. Patients who develop a paravalvular leak have a higher likelihood of death following TAVI;[5] however, a recent study demonstrated that using CT substantially reduces the incidence of paravalvular aortic regurgitation, when compared to transesophageal echocardiography based sizing – with rates of 7.5% and 21.9%, respec-tively.[6]

A similar balancing act occurs in measuring the ostia. A measurement that is too short will result in the unnecessary exclusion of a patient, while one that is too large has the potential to result in the implantation of a prosthesis that occludes a coro-nary artery.

Schoepf says that helping to deter-mine a suitable access route for the relatively large catheters required by the procedure is another area where the software excels. It offers single-click localization and quantification of the smallest iliac diameter, as well as visualization and subtraction of aortic calcifications. Furthermore, it auto-matically calculates the area and dia-meter of vessels: “Even the most expe-rienced observers derive substantial value from features like these because they improve quantitative accuracy and workflow,” Schoepf says.

Minimizing contrast dose to improve safety

According to Achenbach, one feature of syngo.via that is of particular bene-fit to patients is the automatic calcula-tion of the corresponding C-arm angu-lation for a given CT projection. This

“The fundamental advantage of the software

is that it finds the aortic annulus automatically.”

Professor U. Joseph Schoepf, MD, Department of Radiology,

Medical University of South Carolina, Charleston, U.S.

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feature improves workflow, while also increasing the accuracy of the proce-dure as physicians in the cath lab use the best-possible viewing angle.

Achenbach notes that a large percent-age of patients undergoing TAVI have renal insufficiency, which makes keep-ing contrast dose usage to a minimum an important consideration for patient safety. “There are several methods to find the optimum viewing angle in the cath lab, but they all require contrast dose,” Achenbach says. “If you know which angle to use to look at the aortic valve, you don’t have to do extra imag-ing in the cath lab to find this out.”

Achenbach and Schoepf both use a SOMATOM® Definition Flash Dual Source CT scanner for TAVI planning to fur-ther minimize contrast dose. Planning the procedure requires a relatively large scan range, from the shoulder to the hip, but the speed with which the scanner acquires data allows them to keep contrast dose to a minimum. In a study of 42 patients, Achenbach and his colleagues were able to assess aortic root anatomy and vascular access in less than 2 seconds, using 40 mL of iodinated contrast agent.[7] “That we can do everything so quickly and with so little contrast is of great benefit to patients undergoing the TAVI proce-dure,” Achenbach says, “and you’re not sacrificing any image quality.”

Improving outcomes, reducing costs

Patients who undergo TAVI have sub-stantially shorter hospital stays than those undergoing surgical valve replacement.[3] Also, patients treated medi-cally have higher rates of rehospital-ization than those undergoing TAVI.[1]

By improving patient outcomes, the accuracy and safety offered by syngo.via has the potential to decrease costs further. Achenbach notes that TAVI pro-cedures require a large clinical team; therefore, even saving 10 to 15 min-utes during the procedure by deter-mining the optimal viewing angle in advance can make a big difference.

As physicians’ experience with the pro-cedure grows, Schoepf and Achenbach believe that there will be fewer compli-cations and better outcomes. Currently,

two major manufacturers produce the prostheses, but the physicians expect increased competition from other manufacturers to drive down costs further.

TAVI is currently indicated for patients who are inoperable because of comor-bid conditions, as well as those who are considered a high surgical risk. However, the minimally invasive nature of the procedure makes it appealing to younger and healthier patients: “As the results of the procedure get better and better, there’s less incen-tive to do conventional surgery, even maybe in healthier patients,“ Achenbach says. “So the question of who receives this procedure and who undergoes conventional surgery will constantly need to be recalibrated.”

With the SOMATOM Definition Flash very little amounts of contrast are required to acquire the entire anatomy relevant for TAVI planning (only 40 mL in this case)Courtesy of University of Erlangen-Nürnberg, Erlangen, Germany

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References[1] Leon MB, et al. Transcatheter aortic-

valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363:1597-607.

[2] Holmes DR, et al. 2012 ACCF/AATS/SCAI/STS expert consensus document on transcatheter aortic valve replacement. J Thorac Cardiovasc Surg. 2012 Sep; 144(3):e29-84.

[3] Smith CR et. al., Transcatheter versus Surgical Aortic-Valve Replacement in High-Risk Patients N Engl J Med 2011; 364:2187-2198).

[4] Schoepf JU et. al., Automated annulus assessment accuracy in comparison to standard software and manual assess-ment. RSNA 2012

[5] Tamburino C et. al., Incidence and predictors of early and late mortality after transcatheter aortic valve implan-tation in 663 patients with severe aortic stenosis. Circulation, 123 (2011), pp. 299-308

[6] Jilaihawi H, et al. Cross-sectional computed tomographic assessment improves accuracy of aortic annular sizing for transcatheter aortic valve replacement and reduces the incidence of paravalvular aortic regurgitation. J Am Coll Cardiol. 2012;59:1275-1286

[7] Wuest W, et al. Dual source multide-tector CT-angiography before Trans-catheter Aortic Valve Implantation (TAVI) using a high-pitch spiral acquisition mode. Eur Radiol. 2012 Jan;22(1):51-8.

Sameh Fahmy, MS, is an award-winning freelance medical and technology reporter based in Athens, Georgia, USA.

The statements by Siemens’ customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical” hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.

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Further Information

www.siemens.com/CT-TAVI

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A hospital that formerly served coal workers and their families has reinvented itself as a modern center of medical care. A distinct focus lies on the catheter-based treatment of life-threatening aortic aneurysms, a method that requires regular CT follow-up. The SOMATOM® Definition Edge has helped the hospital “Knappschaftskrankenhaus” in Bottrop in Germany to speed up these examinations and to reduce radiation exposure considerably.

By Philipp Grätzel von Grätz, MD

Fighting Aortic Aneurysms with Modern CT Technology

Svenja Hennigs, MD, is Head of the hospital’s Department of Radiology and Nuclear Medicine at the “Knappschaftskrankenhaus” in Bottrop, Germany.


The abdominal aorta is the main sup-plier of blood to the abdomen and the lower extremities. Technically, it is a flexible tube with an average diameter of around two centimeters. Most peo-ple will never be aware of what is the largest artery in the human body. It is an organ that normally works silently for decades. But there are exceptions: Approximately one in thirty adults will develop an aneurysm in the abdominal aorta – defined as an increase in vessel diameter to more than three centimeters.

Stent treatment as a new standard of care

Aortic aneurysms with a diameter of more than four to five centimeters are considered critical from a medical point of view. The larger the diameter, the higher the risk of a rupture. And a rup-ture of this high-volume, high-pressure artery can easily result in death: Nine out of ten patients with this condition will die. The perfidious thing about these ruptures is that they happen without warning, which is why abdominal aortic aneurysms are sometimes called the “silent killers.”

Ruptures of aortic aneurysms, in other words, need to be avoided at all costs, and they can be. Aortic aneurysms are a treatable condition. For decades, open surgery was the method of choice. Today, most aortic aneurysms are treated by catheter-based implantation of aortic stents – a quicker and far less invasive method of permanently stabilizing the artery. The Knappschafts- krankenhaus in Bottrop is one of sev-eral hospitals that have specialized in this new method. “Our vascular sur-geons perform more than 150 of these procedures per year. This means that our hospital is among the leading insti-tutions in Germany in this field,” says Svenja Hennigs, MD, Head of the hos-pital’s Department of Radiology and Nuclear Medicine.

CT as a tool for planning and follow-up

There is a good reason why Svenja Hennigs, as a radiologist, is such an advocate of aortic stenting: Without modern radiology, and particularly modern CT examinations, stent treat-ments of aortic aneurysms would

be unthinkable. Every single patient needs numerous CT examinations before and after the stent implanta-tion. The radiologist is the indispens-able partner of the vascular surgeon who is confronted with an aneurysm patient.

First of all, the CT is a planning tool: “We need a good reconstruction of the aorta and the origins of the renal and mesenteric arteries before the intervention to choose the ideal pros-thesis,” explains Hennigs. “This is why we use thin slices of one millimeter to get the necessary raw data and to be able to provide a proper 3D model for our surgeons.”

After the stent implantation, the CT examination becomes the single most important tool for following up the patients. The vascular surgeons at the Knappschaftskrankenhaus examine the patients on the day after the implantation. There are further follow-up examinations after three, six and twelve months. Later on, the frequency of examinations depends on the indi-vidual situation. Most patients come at least once a year. “This means that we have far more CT examina-tions of aortic aneurysm patients per year than we have surgeries. At the moment, the department of radiology performs 15 such examinations per week. And this number will probably increase further in the years to come.”

Watching out for endoleaks

The most important reason for regular CT follow-up examinations is the search for endoleaks. These are defined as persistent blood flow within the aneurysm sac. There are five dif-ferent types of endoleak with different characteristics and different degrees of clinical relevance. As a rule, an endo-leak increases the risk of an expan-sion of the aneurysm and, ultimately, the risk of rupture. This is why endo-leaks need to be detected and closely monitored. In some cases, a second intervention may be necessary.

The problem with repeated CT exami-nations is that they add up to fairly high radiation dosages over the years. “Together with tumor patients, aortic aneurysm patients are probably the patients with the highest radiation exposure,” says Hennigs. But there is good news for the aneurysm patients at the Knappschaftskrankenhaus. Thanks to the new SOMATOM Definition Edge CT system that was installed in Bottrop in March 2013, the average radiation dose per exam-ination has been reduced considerably.

Cutting-edge technology slashes radiation dose

Hennigs recalls that the hospital had been working with a 64-slice CT sys-tem for many years. “At some time,

Without modern radiology, and particularly modern CT examinations, stent treatments of aortic aneurysms are unthinkable – even in Knappschaftskrankenhaus in Bottrop.

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we started thinking about upgrading to a new one. When I heard about the SOMATOM Definition Edge in 2012, I was immediately interested. We learned that the new Stellar detector and the iterative reconstruction algo-rithm SAFIRE can lead to a reduction in radiation dose of up to 60 percent* under optimal conditions. This really thrilled us, because it was exactly what we were looking for.”

Siemens Stellar detector is the first fully-integrated detector. It reduces electronic noise, which helps to reduce radiation dose and to improve spatial resolution by generating ultra-thin slices.

When the new CT was installed in Bottrop, the radiologists there were

quickly convinced of the system’s benefits.

“In a lean patient with an aortic aneu-rysm, we often need less than half the radiation dose than we did with the previous 64-slice system.” As expected, adipose patients are some-what more challenging. “But even in these situations, the dose is down by 20 to 30 percent in many patients.” Together with Siemens, Hennigs is currently evaluating the average dose reduction that was achieved with the SOMATOM Definition Edge in a series of 50 aortic aneurysm patients.

Assistants allowed to think

The reduction in radiation dose is not only good for aortic aneurysm patients: “It’s good for every patient who needs

a CT. And it is particularly good for tumor patients or certain patients with neurological conditions who need to be examined again and again,” explains Hennigs. Another impressive example that she cites is patients who need preventive CT examinations for lung tumors. Such examinations are being carried out on asbestos workers. But they are also increasingly recommended for heavy smokers. “In past days, a conventional lung CT would require a radiation dose of 8 to 10 millisievert (mSv). Modern low-dose CTs bring that down to 3 to 4 mSv. With the SOMATOM Definition Edge, we are able to do a low-dose CT of the lung at 1 to 1.5 mSv. And believe it or not, we had one patient who needed as little as 0.8 mSv.”

In combination with the new Stellar detector, the iterative image recon-struction technology SAFIRE is the key to achieving the outstanding low radi-ation doses. SAFIRE features a set of pre-specified programs. It also allows for a certain degree of manual control, as Svenja Hennigs explains: “We turn SAFIRE on for practically every patient. The radiological assistant then decides individually whether he or she can risk going down a little further or not. The SOMATOM Definition Edge is, in fact, the first CT system for many years that allows the radiological assistant to think in new directions.”

Quicker examinations, higher image quality

Having worked with the SOMATOM Definition Edge for four months, Hennigs and her colleagues have dis-covered various additional benefits

The Knappschaftskrankenhaus Bottrop opened in 1931 as a hospital for miners who worked in the numerous coal mines of the Ruhr Basin in Germany – at that time, the powerhouse of Central Europe. There is still a small sculpture in the entrance hall that reminds visitors and patients of these roots: St. Barbara, patron saint of miners. Today, the Knapp- schaftskrankenhaus is a modern hospital for acute

and regular care with 346 beds in nine clinical depart-ments. More than 50,000 patients are treated per year, a large number of which are outpatients. The department of radiology keeps nine radiologists and 15 radiology assistants busy. Apart from the SOMATOM Definition Edge, they have a Siemens MRI, three angiography systems, a mammography unit, and two workplaces plus nuclear medicine and ultrasound.

Coal in the genes

The Knappschaftskrankenhaus in Bottrop is among the leading institutions in Germany in treating aortic aneurysms by catheter-based implantation of aortic stents.

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to the new system. First of all, speed. “We are now able to perform a thoracic CT within 3 seconds, and an abdomen takes around 12 seconds. It’s extremely quick. The limiting factor is not the examination, but getting the patient in and out again.”

Hennigs is also very impressed by the image quality that the SOMATOM Definition Edge provides: “I would put it this way: The images are more bril-liant. This becomes particularly obvious with CT examinations of bone fractures. When I compare high-resolution images of fracture lines from the same patient recorded with the previous 64-slice CT against the new one, the overall impres-sion is totally different. It is far better now, much clearer and more detailed.”

A quantum leap

When looking at the modern CT sys-tems available on the market last year, Hennigs also considered other vendors instead of SOMATOM Definition Edge

system. “But I thought that the more compact system in combination with high end detector technology fitted our needs better.” The fact that the SOMATOM Definition Edge also fea-tures Dual Energy (DE) technology made the decision even easier: “Our urologists and nephrologists, in par-ticular, asked us to provide DE tech-nology for visualizing urinary tract stones and uric acid crystals. So we decided to also acquire the DE appli-cations that come with the SOMATOM Definition Edge, and we are now using it regularly. It provides excellent DECT images.“

All in all, neither the radiologists nor radiological assistants in Bottrop miss the previous 64-slice system: “The SOMATOM Definition Edge really is a quantum leap forward. We are still discovering new possibilities with it. And once you have learned to work with all its features, the results are fantastic.”

* In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appro-priate dose to obtain diagnostic image quality for the particular clinical task. The following test method was used to determine a 54 TO 60% dose reduction when using the SAFIRE reconstruc-tion software. Noise, CT numbers, homogeneity, low contrast resolution and high contrast resolu-tion were assessed in a Gammex 438 phantom. Low dose data reconstructed with SAFIRE showed the same image quality compared to full dose data based on this test. Data on file.

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Previous 64-slice system (Fig. 1A) SOMATOM Definition Edge (Fig. 1B)

kV-Setting 120 kV, 95 mAs 100 kV, 92 mAs

DLP 318 mGy cm 158 mGy cm

CTDI 7.32 mGy 3.66 mGy

Image comparison for follow-up scan of same patient between previous 64-slice system (Fig. 1A) and new SOMATOM Definition Edge (Fig. 1B) with SAFIRE at half the dose with comparable diagnostic image quality. Courtesy of Knappschaftskrankenhaus Bottrop, Germany

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Philipp Grätzel von Grätz is a medical doctor turned freelance writer and book author based in Berlin, Germany. His focus is on biomedicine, medical technology, health IT, and health policy.

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Recently published scientific studies present evidence of the additional benefits of CARE kV and the Adaptive 4D Spiral – which until now had only been described in terms of potential.

CARE kV

Adjusting the tube voltage for every CT scan can help deliver the right dose to every patient; and varying kV values for different applications can help achieve optimal image quality. This potential was known but the adjustments were too complicated to do manually, as the tube current then needs to be adapted accordingly.

CARE kV automatically selects the tube voltage and CARE Dose4D adapts the tube current.

Many scientific studies have shown the benefits of CARE kV for different types of examination.[1,2] Yet, stud-ies focusing on pediatric CT imaging with CARE kV had been lacking until researchers from Mallinckrodt Institute of Radiology, St. Louis, US, published their latest results. In their study they first evaluated the potential of CARE kV for CT Angiography exami-nations using three different-sized pediatric phantoms.[3]

In the second step, these findings were used in a study with 87 pediatric patients.[4] The tube voltage set as reference was 120 kV. With CARE kV, the tube voltage was lowered to 100 kV, 80 kV, or even 70 kV in 82 of these 87 patients (i.e. 94% of the cases). Image quality was assessed subjectively; 15 of these cases were also compared with a previous CT scan at 120 kV. Contrast-to-noise ratio (CNR) was evaluated in these cases. The authors outline the implications for patient care: “Use of automated kilovoltage selection technology appears to be an effective strategy for optimizing tube voltage selection and reducing radiation dose while maintaining image quality in contrast- enhanced pediatric CT and should be introduced into routine clinical practice.”[4]

Adaptive 4D Spiral

CT Perfusion imaging with Adaptive 4D Spiral delivers qualitative and quantitative information about perfu-sion patterns. In recent years, scien-tific studies have been published that focus on different organs and tumor entities.[5,6] Usually, the examina-tions had to be performed with a tube

This examination of a baby was included in a study.[4] The VRT shows well enhanced mediastinal vessels and a persistent left superior vena cava (arrow). The effective dose for this scan was 0.36 mSv.Courtesy of Mallinckrodt Institute of Radiology, Saint Louis, USA

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voltage of 100 kV. In a phantom study, CT perfusion examinations with SOMATOM® Definition Flash – either with conventional detector technology or the Stellar detector – were com-pared at 80 kV and 100 kV. In view of the minimized electronic noise, the authors conclude: “The Stellar detector allows the routine use of 80 kV for abdominal perfusion imaging. For identical CNR this reduces the dose by 35% compared to 100 kV.”[7]

New cancer treatment options – including anti-angiogenic drugs that influence blood supply to a tumor – have been introduced and are still under intense evaluation.

Researchers from University of Lille, France have used Adaptive 4D Spiral technology to assess treatment out-comes in the case of non-small-cell lung cancer (NSCLC).[8] In group 1, 17 patients received conventional chemotherapy, 23 patients in group 2 were also given an anti-angiogenic drug (Bevacizumab). The perfusion information was derived before treat-ment begin and then at three later points in time. Perfusion was quanti-fied using two new parameters: total tumor vascular volume (TVV, in mL), which is based on blood volume; and total tumor extravascular flow (TEF, in mL/min), which is based on the volume transfer constant ktrans – also known as flow extraction product. In addition, RECIST (Response Evaluation Criteria in Solid Tumors) data was col-lected to assess tumor size. Given the changes in perfusion parameters and in RECIST, the authors summarized a key finding: “Specific therapeutic effects of anti-angiogenic drugs can be detected before tumour shrinkage.”[8]

News

By Heidrun Endt, MD


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New Applications for CARE kV and Adaptive 4D Spiral


Outlook

Since the introduction of CARE kV and Adaptive 4D Spiral, several studies have been published indicating broad potential application. This portfolio has now been extended. In the case of CARE kV, initial studies have shown the benefits when scanning young patients. Further research is expected on low kV imaging in pediatric CT, in particular. For Adaptive 4D Spiral, the perfusion evaluation of tumors was scientifically validated for different clinical questions.[5,6] New develop-ments in other areas, such as with the Stellar detector, may lead to new options for existing technologies.[7] The possibility of perfusion imaging at 80 kV will be of great interest to the scientific community. The study from France shows that with Adap-tive 4D Spiral technology a prediction of a treatment response to anti-angio-genic drugs is possible for cases of NSCLC. In their conclusion, the authors indicate the potential: “If these prom-ising preliminary results can be con-firmed by larger studies, perfusion CT could represent a very useful non-invasive tool for thoracic oncologists to manage anti-angiogenic treat-ments in clinical practice with the objective of avoiding pointless thera-pies and their potential adverse events as well as cost savings.”[8]

The examination of this 62-year-old patient suffering from an adenocarcinoma of the lung in the left lower lobe was included in the study.[8]Images on the left-hand side show the situation before treatment, images on the right-hand side were obtained after one cycle of therapy (including anti-angiogenic drugs).Conventional images (mediastinal window) are shown in Fig. 2A and 2B. Perfusion information can be derived from Fig. 2C and 2D (TVV) and 2E and 2F (TEV).The perfusion maps show a decrease in vascularity (TVV from 4.4 mL to 1.6 mL; TEF from 4.3 mL to 2.2 mL) whereas no change in tumor size could yet be seen in the mediastinal images.Courtesy of University Hospital of Lille, France

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References[1] Eller A, et al. Invest Radiol. 2012

Oct;47(10):559-65.[2] Park YJ, et al. J Cardiovasc Comput

Tomogr. 2012 May-Jun;6(3):184-90.[3] Siegel MJ, et al. Invest Radiol. 2013

Aug;48(8):584-9.[4] Siegel MJ, et al. Radiology. 2013

Aug;268(2):538-47.[5] Goetti R, et al. Invest Radiol. 2012

Jan;47(1):18-24.[6] Reiner CS, et al. Invest Radiol. 2012

Jan;47(1):33-40. [7] Klotz E, et al. Performance evaluation

of a new CT detector with minimal electronic noise for low dose abdominal perfusion imaging. Insights Imaging (2013) 4 (Suppl 1):200

[8] Tacelli N, et al. Eur Radiol. 2013 Aug;23(8):2127-36.


One of the first ever installations of a SOMATOM® Perspective CT scanner was at Sainte-Marie Medical Imaging Center in Osny, near Paris, France in January 2012. One and a half years later, SOMATOM Sessions returned to the center to discover whether the initial enthusiasm and hopes were justified. The positive assessment made at that time was entirely confirmed. And – particularly attractive in this era of austerity – at an affordable price.

By Christian Rayr

Back Among the Pioneers

The initial positive assessment of the SOMATOM Perspective has continued at Sainte-Marie Medical Imaging Center in Osny, near Paris, France.


Alexandre Fuchs, MD, Sainte-Marie Medical Imaging Center, Osny, France

“eMode reduces material wear, extends the machine’s

lifetime, and eliminates downtime. We’ve had

no breakdowns or annoying problems to report.”

Alexandre Fuchs, MD is a doctor, spe-cialising in diagnostic and co-director of Imagerie Medicale Sainte Marie. His initial, positive assessment of the SOMATOM Perspective has not changed. The center is guided by the principle of achieving the utmost excellence and, therefore always seeks the best diag-nostic equipment for its patients. And this means that Fuchs is in a position to make comparisons. “The SOMATOM Perspective delivers perfect diagnostic efficiency“ he notes. So far, almost 10,000 patients have benefited from its use. Franck Lamesa, general super-visor of the Sainte-Marie Medical Imaging Center, adds: “The number of scans conducted currently stands at 12,400. With the SOMATOM Perspective, we have performed approximately 5,500 abdominopelvic scans, as well as 2,300 thoracic scans, 1,200 lumbar scans, 800 brain scans, and 800 sinus scans.”

Good results have been achieved in all pathological areas: cancer, pediatrics, rheumatology, cardiology, and neurol-ogy, to name just a few. “Work in oncol-ogy is ongoing here,” Fuchs points out, “because we collaborate closely with the Sainte-Marie Medical Imaging Center and its cancer treatment center next door. For us, the work involves standard scans. Image acquisition is

perfect, and all the preparatory and analytical work is carried out with the help of syngo.via. We are one of the major users of this software, espe-cially its applications for oncology.” Post-treatment image data are vali-dated by the radiologist and are then stored automatically so that treat-ment process can be tracked.

Significantly lower radiation doses

Levels of radiation dose pose an acute problem both in oncology and pedi-atrics. There must be no question of radiation overdoses when examining a child’s abdomen, thorax, or head. Extreme caution is also essential with cancer pathology where multiple images are required for diagnosis, during treatment, and at the regular check-ups that follow. Thanks to iterative reconstruction with SAFIRE (Sinogram Affirmed Iterative Recon-struction), significantly lower radia-tion doses are possible. “In overall terms, we are satisfied with SAFIRE for pediatrics as well as oncology,” Fuchs comments. Based on experience, the technicians and radiologists at the Sainte-Marie Imaging Center stated that SAFIRE enables an average dose reduction of 30 to 40 percent, or even 50 percent compared to scans

without SAFIRE. In most cases, reduc-ing the power – and therefore the radiation – does not affect the quality of the image.

Surgery and treatment for overweight persons are among the fields in which the Sainte-Marie Medical Imaging Center excels. This year again, the clinic was placed among the top ten clinics in the Ile- de-France region according to the 2013 Ranking of Hospitals and Clinics” published by le Figaro Magazine.“ “We work in liaison with the obesity treatment center at the Sainte-Marie Medical Imaging Center,” Fuchs explains. “Radiography and echography are the first investi-gations requested prior to bariatric surgery.” When talking about CT-scans, Fuchs explains, “we mostly deploy the SOMATOM Perspective to detect pathologies – or, more often, multi-pathologies – related to overweight.”

Improved temporal resolution for heart scans

In cardiology, temporal resolution is the most important factor. To achieve the lowest possible value, the spiral must rotate as fast as possible. On the SOMATOM Perspective, especially with the help of iTRIM software, satisfactory results can be achieved.

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With optimizing protocols to the right dose, a perfect balance between image quality and radiation exposure can be achieved.

Technicians praise the simple operation of the SOMATOM Perspective.

Christian Rayr is a freelance journalist based in Paris, France. He writes for various medical publications and covers medical topics for the general media.

Likewise for imaging of the inner ear and the petrous portion of the tem-poral bone, centralized collection and analysis of the raw data have made it possible to optimize the protocols. That delivers more than satisfactory results in terms of slice thickness and perfect balance between image qual-ity and radiation dose.

An efficient, economic scanner

Overall it is evident that the SOMATOM Perspective is the preferred choice for radiology centers. A large number of SOMATOM Perspective scanners have been sold in France and a lot of them are now in use in the Paris region. Ever since the SOMATOM Perspective was installed at the Sainte-Marie Imaging Center, it has attracted visits from numerous specialists from countries such as Belgium, Switzerland, the USA, Korea, Japan, and Australia. Although economic constraints exercise ever-greater pressure on budgets, reducing the quality of care is not an accept-able option at all. Everyone is aware of the good price position and low operating costs for the SOMATOM Perspective. It can be installed easily and quickly – in just one day. It is very lightweight and so does not

require floor reinforcements, nor does it take up much space. Thanks to its air-cooling system, it does not require water-cooling, and use of the eMode software makes this scanner even more reliable and durable.

eMode for a perfect scan

eMode is a software that automati-cally sets the scan parameters to encourage economical use of the sys-tem, but without ever compromising image quality or dose. “This feature reduces material wear, extends the machine’s lifetime, and eliminates downtime. We’ve had no breakdowns or annoying problems to report,” Fuchs notes.

Technicians praise the simple opera-tion of the SOMATOM Perspective. They use eMode on almost every scan, with an average usage of at least 99 percent. Only cases of massive obesity leads to non-eMode scans. They also appreciate the machine’s rapid image acquisition with eMode. If the slightest problem arises in the scan settings – for example, should a patient go beyond the standard protocols − a warning lamp lights up. To adjust the scan parameters, the technician simply has to press the ‘Fast Adjust’ button to automatically

adjust the scan parameters and to scan on eMode again. “With this machine, a technician could easily carry out 12 scans per hour,” Fuchs comments. “We perform six per hour: One patient every ten minutes, including emergen-cies, which is a fairly good rate. What’s more, we investigate some patholo-gies that take longer such as cancers or vascular problems. As a matter of fact, it’s no longer the machine that sets the limit nowadays, it’s actually the radiologist. We need to be able to duplicate ourselves!”

Further Information

www.siemens.com/ SOMATOM-Perspective

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online community to share experi-ences with fellow researchers and Siemens experts. The global exchange of research ideas may help to trans-form individual research endeavors with limited resources into effective collaborative efforts and may even facilitate the set-up and management of international multicenter studies.

New developments

With the launch of syngo.via Frontier, Siemens is opening up access to a range of cardiovascular and Dual Energy CT research prototypes. In the future, new prototypes may also be made available in other fields and from other external partners, giving the user the chance of a head start on current research questions. For customers with strong programmer know-how, an optional package is available that allows design and implementation of new prototypes. That will help to leverage personal research endeavors.

cated prototype store. The research prototypes are not medical devices and are therefore not intended for use in clinical routine. They are not tied to the regular product develop-ment cycle. Thus new prototypes are available for research much sooner than released applications.

The idea behind opening access to research software with syngo.via Frontier is as follows: Traditional stand-alone research software is often installed on a computer away from the everyday reading location. This is a clear downside, because this lack of integration into the routine reading workflow results in tedious data and result transfers. The new syngo.via Frontier, however, provides a direct connection between the clinical syngo.via server and the dedicated syngo.via Frontier server. The research prototypes may thus be accessed from any syngo.via client in the institution and are directly integrated in the usual syngo.via user interface. This tight integration enables the researcher to send and retrieve data and result images easily for inclusion in an ongoing on site research study, for instance.

With syngo.via Frontier, the user also obtains access to an international

At the RSNA 2013, Siemens introduced syngo.via Frontier*, a novel concept in the field of medical imaging. It opens up access to research prototypes, pro-vides the means for individual prototype development, and allows participation in a global network of fellow research-ers. Engaging in state-of-the-art research will therefore be possible for a larger group of interested CT users.

Research in medical imaging is as important and rewarding as it is excit-ing – whether evaluating new scan protocols for clinical practice, monitor-ing treatment success, or testing and analyzing new advanced imaging software. Before entering the market, underlying algorithms within these applications have already been thor-oughly tested by Siemens together with collaborating customers. Active participation in an initial evaluation of a prototype has been reserved to insti-tutions with a collaboration agreement with Siemens – until now.

Opening access to research

syngo.via Frontier is a novel research tool offered to literally every clinical institution. Any interested syngo.via user can buy and install it. Prototypes currently under development can then easily be downloaded from the dedi-

syngo.via Frontier – Gateway to an Open Research Environment

1

The prototype Siemens DE Rho/Z maps helps to differentiate tissue based on electron density and effective atomic number.**

1 The prototype Siemens DE Scatter Plots visualizes energy dependencies for detailed analysis of material homogeneity.**

2

Further Information

www.siemens.com/ syngo.via-frontier

By Philip Stenner, PhD


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2

IodineLine BoneLine TissueLine

Low

kV

(1

00

) V

alu

e [H

U]

High kV (Sn 140) Value [HU]

* This product is 510(k) pending. Not available for sale in the U.S. ** Accessible with syngo.via Frontier. Not for clinical use.


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tube or the fully integrated detector design from the Stellar and StellarInfinity detectors. By implementing new advanced models of these crucial scanner geometry com-ponents into the iterations cycles, ADMIRE can support new levels of image quality.

Without compromising on the dose reduction capabilities, ADMIRE now enables improved sharpness or low-contrast detectability, minimized artifacts – even applied to thicker slices of 3 or 5 mm. This, combined with a new genera-tion of image-processing computers, will allow ADMIRE to transfer its potential into clinical practice. Introduced together with the SOMATOM Force at the RSNA 2013, ADMIRE will be made available for all systems with Stellar detectors later in 2014.

International Right Dose Image Contest 2013

Once again, the International CT Image Contest has attracted excellent submissions from users of SOMATOM CT scanners from across the globe. Siemens Healthcare announced the winners of the competition in eight clinical categories. Over 320 cases were submitted from more than 135 institutes and hospitals in countries from all continents. Any users of a CT scanner from the SOMATOM® family had the chance to present their best clinical images to an international jury of recognized experts. The winning images were shown during the congress of the 99th RSNA 2013 in Chicago.

New award for sustainable dose management

In addition to the existing eight clinical categories (Cardiac, Dual Energy, Neuro, Oncology, Pediatrics, Routine, Trauma, and Vascular) a further award was included in this year’s competition for the institution with the best dose reduction strategy.

Expert jury

Leading radiologists from around the world formed the jury: Professor Harold Litt, MD, University of Pennsylvania, Philadelphia (USA), Professor Willi A. Kalender, MD, PhD, University of Erlangen-Nuremberg Germany),Professor Marilyn J. Siegel, MD, Mallinckrodt Institute of Radiology, St. Louis (USA),

At the 99th Radiological Society of North America (RSNA) 2013 in Chicago, Siemens underlined its commitment to delivering the right balance between image quality and radiation dose – or in short: the CARE Right philosophy. Showcasing innovations as well as impressive clinical results from the “Right Dose Image Contest”, Siemens highlighted clearly its role as trendsetter in delivering sustainable solu-tions to minimize radiation exposure.

ADMIRE – Next generation iterative reconstruction

Along with the SOMATOM Force, Siemens also introduced its latest milestone in right dose technology: Advanced Modeled Iterative Reconstruction – ADMIRE. In 2010, Siemens introduced its raw-data based iterative recon-struction SAFIRE (Sinogram Affirmed Iterative Reconstruc-tion). With proven dose reduction potential of up to 60%* together with performance values that make it truly suitable for clinical routine, SAFIRE is now used daily at hundreds of sites – often for every examination.

Building on these proven outcomes, ADMIRE now addition-ally leverages Siemens’ superior scanner technologies such as the flying focal spot in the STRATON and VECTRON

Continuous Commitment to the Right DoseBy Ivo Driesser and Jan Freund


ADMIRE now addition-ally leverages Siemens superior scanner technologies like the flying focal spot in the STRATON and VECTRON tube or the fully- integrated detector design from the Stellar and StellarInfinity detectors.


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Associate Professor Peter Schramm, MD, University Medicine Goettingen (Germany), Professor Elliot K. Fishman, MD, Johns Hopkins University, Baltimore (USA), Professor Hyun Woo Goo, MD, University of Ulsan (South Korea),Professor Hatem Alkadhi, MD, University Hospital Zurich, (Switzerland),Aaron Sodickson, MD, PhD, Harvard Medical School, Boston (USA), Kheng-Thye Ho, MD, PhD, Khoo Teck Puat Hospital (Singapore)and Professor Uwe Joseph Schoepf, MD, Medical University of South Carolina (USA).

Facebook community

This year, the Facebook fan page has been particularly successful inviting everyone to interesting discussions about the most impressive cases submitted. Over the five-month duration of the contest – from June to October 2013 – a fan community of over 17,200 users “liked”, viewed, and commented on the images. Image Contest fans could also vote for their favorite picture in a public vote. The Siemens Internet page devoted to the contest received over 84,700

hits. This level of interest suggests that the aim of the contest was achieved – to raise awareness of sustainable dose management and the importance of balancing low dose with diagnostic quality imaging.

More information on the Image Contest including all clinical details and respective protocols is available at:

Further Information

www.siemens.com/care-right www.siemens.com/image-contest

Pick of the Month June*

Submitter: Ronald Booij, Erasmus Medical Center Rotterdam, the Netherlands

Patient History: A seven-month-old child with severe aortic coarctation was referred for CT imaging. The patient indicated absence of groin pulsations and hypertension in upper body part. Examination by ultrasound suggested presence of double aortic arch.

Diagnosis: The investigation results showed indication of a normal relationship between the atria, ventricles, and large vessels. A severe aortic coarctation distal of the left subclavian artery and strong collaterals through the intercostal artery to the aorta descendens could be depicted. There was no evidence of double aortic arch.

Dose management: We scanned the young patient with the CARE kV option. We use almost all of our adult and child protocols with this option to keep our image quality preferences constant. In this case, the system used 70 kV and 16 eff. mAs. With the help of SAFIRE, CARE kV (the dose optimization slider on position 11) and a strong dose modulation curve for CARE Dose4D the optimal image quality with the lowest dose was achieved.

Comments: Due to the high pitch technology, even this free-breathing patient had no motion artifact. No anesthetics were used.

Scanner: SOMATOM Definition Flash

Effective dose: 0.28 mSv

*Winners had not been decided at the time of the editorial deadline.

* In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The following test method was used to determine a 54 to 60% dose reduction when using the SAFIRE reconstruction software. Noise, CT numbers, homogeneity, low-contrast resolution and high contrast resolution were assessed in a Gammex 438 phantom. Low dose data reconstructed with SAFIRE showed the same image quality compared to full dose data based on this test.

Data on file.


Siemens True Dual Energy provides many applications available for daily clinical use. True Dual Energy not only enables faster and more reliable diagnoses, but also further extends the application spectrum of CT and turns complex examinations into easy routine.

Thanks to pioneering application development, CT examination meth-ods such as Dual Energy (DE) scan-ning have expanded into many new clinical fields.

Single Source DE to charac-terize tissue or calculi

The introduction of Single Source DE imaging for the SOMATOM® Definition Edge and SOMATOM Definition AS made it possible to add tissue charac-terization to morphology. The routine- ready Single Source DE scan mode is available on every SOMATOM Definition AS – even on the 20-slice configuration – and has just recently also been introduced for the SOMATOM Perspective family. With Single Source DE, a range of applica-tions has emerged such as syngo.CT DE Calculi Characterization.* By visu-alizing uric acid crystals in joints, a diagnosis of gout can be confirmed with certainty. Monoenergetic imag-ing for routine-ready metal artifact reduction can overcome many diffi-culties in CT imaging. More confident diagnostic evaluation prior to surgical procedures – such as the removal of metal plates or screws – is also possible.

Introducing new applications

For SOMATOM Definition AS+ and SOMATOM Definition Edge scanners, two more application classes are being introduced: syngo.CT DE Virtual Unenhanced* is designed to perform a material decomposition into iodine contrast agent, fat, and liver tissue. It also creates a virtual non-contrast image. Additionally, syngo.CT DE Brain Hemorrhage* is designed to identify bleedings and lesions by displaying the contrast agent concentration in the brain.

Dose-optimized DE

All of these DE applications are per-formed in a dose-optimized DE scan mode. In order to avoid doubling the dose, both scans are performed at approximately half the dose of a con-ventional 120 kV scan. Furthermore, Siemens Single Source DE scan mode utilizes all dose reduction functional-ities: e.g. CARE Dose4D for real-time tube current modulation, or SAFIRE** for the reduction of tube current through iterative reconstruction.

Full flexibility for system configuration and future upgrades

The new Single Source DE functionality is not only limited to new installations. Systems already installed can also benefit: SOMATOM Definition AS+ and SOMATOM Definition Edge scanners can easily be upgraded with the new Single Source DE applications.

Single Source DE scan: Monoenergetic shows a metal artifact-reduced image for undisturbed view of the implants and the surrounding tissue. Courtesy of LMU Grosshadern, Munich, Germany

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1

Charting New Paths with True Dual Energy

By Susanne Hölzer and Jürgen Merz, PhD


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Single Source DE scan: syngo.CT DE Brain Hemorrhage* shows iodine concentration in the brain, to rule-out intra-cranial bleeding. Courtesy of CHU Carémeau, Nîmes, France

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Further Information

www.siemens.com/ dual-energy

3 * This product is 510(k) pending. Not available for sale in the U.S.

** In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task.

Single Source DE scan: syngo.CT DE Virtual Unenhanced* shows enhanced lesion in the liver. Courtesy of LMU Grosshadern, Munich, Germany

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The majority of countries in Europe have to deal with the consequences of the crisis in the global economy leading to shrinking purchasing power and reduced national budgets. Health-care service providers are greatly affected by this vicious circle, as health-care expenditure is one of the largest costs for these countries. In the U.S., too, where affordable healthcare is a major goal for the next few years, healthcare institutions have to do more with less, because of tremen-dous budget cuts. On the other hand, clinical demands worldwide are increasing rapidly – high-end clinical care, which a decade ago was avail-able only in selected regions and for some patients, has now become the standard level of care. This is why a well thought-out investment and the efficient use of medical devices are key today to success in clinical prac-tice worldwide.

To meet these requirements, Siemens offers the SOMATOM Perspective – the most economical CT of its class. With a new 16- and 32-slice configu-ration*, the SOMATOM Perspective is entering into a new market segment. The two new configurations combine first-class clinical care and an opti-mized total-cost-of-ownership posi-tion for healthcare institutions. The features and technologies of the SOMATOM Perspective family are designed to accomplish these two objectives, especially in the 16- and 32-slice market segments.

Service providers in healthcare are facing growing economic challenges. At the same time, the demand for seamless healthcare has intensified. To address both these aspects, new SOMATOM® Perspective 16- and 32-slice configurations have been introduced to the SOMATOM Perspective family.

By Florian Hein


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Open Up New Opportunities with New Configurations

A broad clinical portfolio is now available with the new SOMATOM Perspective family from routine scanning in oncology and neurology to complex cardiac imaging. Courtesy of Radiology Department of Israelitisches Krankenhaus, Hamburg, Germany and SAMS Hospital, Lisboa, Portugal

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Economical scanner usage

eMode enhanced with the eStart and eSleep functionalities provides a com-prehensive package known as eCockpit that not only saves electricity costs, but also enhances scanner lifetime. The renowned eMode was introduced two years ago to reduce wear and tear on the CT system. Nowadays, more than 90% of scans performed on SOMATOM Perspectives are eMode scans. Usage of 80% or above is already showing a downtime reduction of more than 20%. Furthermore, customers with a Siemens service contract may choose one of the valuable benefits. Service price reduction of up to 10% or appli-cation training free of charge are just some of the advantages individually designed by the Siemens service orga-nizations in specific countries.

Johann Christian Steffens, MD, from the Radiology Clinic of Israelitisches Krankenhaus in Hamburg, Germany, was one of the first SOMATOM Perspective users. “We use eMode as our standard mode for 98.8% of all scans. We’ve been running the SOMATOM Perspective for two years now and we are still using the first tube,” Steffens explains.

Highest clinical standards with a 16-slice CT

With Single Source Dual Energy, Siemens does not limit the highest clini-cal standards to the upper multislice CT world. For the first time, this tech-nology is available for 16- and 32-slice CT scanners delivering significant additional value in CT image reading. The application syngo Dual Energy Monoenergetic, for example, helps to significantly reduce metal artifacts – a challenge every healthcare institution faces with CT scans when it comes to imaging a hip implant or a complicated fracture (read more on page 34).

The right dose

For best patient care, the raw-data based iterative reconstruction method SAFIRE improves diagnoses while reducing overall dose values by up to 60%**. With 15 reconstructed images per second, SAFIRE is routine ready: This has been proven by existing SOMATOM Perspective users. Every second thorax scan, for example, is

To address growing economic challenges and deliver seamless healthcare, the SOMATOM Perspective family has been extended. 16- and 32-slice configurations have been added to the SOMATOM Perspective 64 and 128.

a SAFIRE scan and some sites even use it for every single scan. In order to make this well-established technol-ogy accessible for literally all patients, SAFIRE is now also available for the 16- and 32-slice segment.

A sound investment

The SOMATOM Perspective family is not closing doors to growth. The investment can be tailored according to the clinical need and business situation of healthcare institutions. They have the possibility to start with a SOMATOM Perspective 16-slice configuration and upgrade to 32, 64, and 128 slices whenever economi-cally sensible or clinically necessary.

This is why the SOMATOM Perspective family not only solves economic chal-lenges; it also opens up new oppor-tunities for healthcare institutions to meet higher clinical demands.

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Further Information

www.siemens.com/ SOMATOM-Perspective


** In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical loca-tion, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The follow-ing test method was used to determine a 54 to 60% dose reduction when using the SAFIRE reconstruction software. Noise, CT numbers, homogeneity, low-contrast resolution and high contrast resolution were assessed in a Gammex 438 phan-tom. Low dose data reconstructed with SAFIRE showed the same image quality compared to full dose data based on this test. Data on file.


Cardiologist Philipp Pichler, MD, is currently investigating CT stress myocardial perfusion imaging. He has already discovered the benefits of Dual Source technology in the SOMATOM® Definition and the advanced cardiac visualization capabilities of the CT Cardio-Vascular Engine.

By Philip Stenner, PhD


“With the new 17-segment polar maps you can quickly and easily assess the size of the affected area. This is definitely a benefit – not only for inexperienced users.”

Philipp Pichler, MD, Vienna General Hospital, Vienna, Austria

In the heart of Vienna, Austria, Philipp Pichler, MD, coordinates an interdis-ciplinary team of cardiologists and radiologists investigating how stress myocardial CT perfusion imaging can help to classify the hemodynamic relevance of coronary stenosis. The team consists of physicians from three different Viennese institutions: The cardiology departments of the General Hospital (Allgemeines Krankenhaus Wien, AKH) and Hanusch Hospital,

and the radiology department of the Confraternität (Wolfgang Dock, MD and Helmuth Mendel, MD). Himself a cardiologist, Pichler enjoys the bene-fits of working with radiologists to achieve a more immediate and com-plete diagnosis of cardiac and of non-cardiac findings.

Pichler works at AKH and Hanusch Hospital, the latter is where he and his colleagues recruit patients for

their study on first-pass myocardial stress perfusion imaging. Consenting patients that meet the inclusion crite-ria (e.g. increased pre-test likelihood of coronary artery disease) are referred to the radiological department at the Confraternität. Here, a SOMATOM Definition and the CT Cardio-Vascular Engine on syngo.via provide all that is required to perform a comprehensive first-pass myocardial perfusion exami-nation. In a first step, patients undergo

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Getting to Grips with Stress Myocardial Perfusion Imaging


a low-dose coronary CTA (cCTA) to assess their coronary status. In case of unclear stenoses, a first-pass enhance-ment stress exam is carried out that is later validated using single photon emission computed tomography (SPECT) still being the gold standard. In the case of hemodynamically relevant ste-nosis, the patients are referred again to Hanusch Clinic to undergo percuta-neous coronary intervention. Unless the patient’s weight indicates other-wise, Pichler runs a 100 kV scan to keep the radiation dose low for the perfu-sion examination.

Minimizing motion artifacts with DSCT

As part of their study, Pichler and col-leagues also focus on interesting side aspects relevant to CT myocardial per-fusion imaging, such as the impact of Single Source CT (SSCT) vs. Dual Source CT (DSCT) on temporal resolution and image quality. A research protocol allows him to reconstruct only the data from one tube, mimicking a SSCT scan. For the 50 patients included so far, Pichler has discovered that the image quality is significantly better with DSCT. He sees the benefit as twofold: Beta-blockage is not applied in the stress perfusion scan as it may cause false negative findings. Moreover, the appli-cation of adenosine increases the heart rate. Both factors require the highest native temporal resolution possible, according to Pichler.

syngo.via facilitates cardiovascular reading

When it comes to reading cCTA and perfusion images, Pichler is extremely satisfied with syngo.via and the CT Cardio-Vascular Engine. “The display of coronary arteries in Curved Planar Reformation (CPR) is not only per-formed extremely quickly, but also very robustly.” He also finds it is especially helpful in certain situations; when evaluating lesion lengths, for instance. “On my previous system, the CPR gen-eration was tedious and manual which is why I never used it. With the auto-mation on syngo.via, the evaluation of CPRs has now become a routine task.”

The ‘Enhancement’ functionality on syngo.via allows him to visualize ischemic areas at the push of a button.

The private clinic Confraternität in Vienna, Austria.

Further Information

www.siemens.com/ ct-cardiology

Together with the 17-segment polar maps, he now enjoys a quicker and more accurate assessment of ischemic areas. “We now use it routinely – it has become more than a simple add-on.” In one case, the polar map was especially useful: A patient had suf-fered from an old infarct that had caused irreversible damage. Some time later, the patient had further compli-cations and developed another perfu-sion defect. After differentiating the results obtained from the rest/stress scans, this new problem appeared to be reversible and was easily distin-guished as such. “With the new 17-seg-ment polar maps, you can quickly and easily assess the size of the affected area. This is definitely a benefit – not only for inexperienced users,” says Pichler. He also enjoys having a com-plete solution for myocardial perfu-sion imaging: From a CT scanner that allows him to freeze cardiac motion with high native temporal resolution, to state-of-the-art reading: “With the current syngo.via, you now have an advanced visualization platform that matches the outstanding quality of your scanners.”

Evaluating myocardial perfusion with syngo.CT Cardiac Function.

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By Philipp Grätzel von Grätz, MD

Modern stroke care would be inconceivable without rapid brain imaging. In Helsinki, reallocating a CT to the emergency department enables thrombolytic therapy to be administered to stroke patients in only 20 min.[1] This pioneer-ing approach to stroke care can be transferred to other countries.[2] New CT technologies, such as dynamic CT Angiography, are likely to help neurologists even further in choosing the best therapy.

Ready for the Next Revolution in Stroke Care?

For Associate Professor Atte Meretoja, MD, (left) and

Professor Markku Kaste, MD, (right) at Helsinki University Hospital

improving stroke care is key.


The first CT revolution at Helsinki Uni-versity Hospital took place in 2004. “At that time, we told our radiologists to move the best CT available from the department of radiology to the emer-gency department,” recalls Professor Markku Kaste, who was Head of the Department of Neurology at Helsinki University for several years. “They were not amused at first, but we man-aged to convince them in the end.”

Streamlining the chain of recovery

The goal was to improve stroke care by streamlining the ‘chain of recovery’ in cases of acute stroke. “In patients with acute stroke, time is brain,” says Kaste. The quicker a patient receives intravenous thrombolytic therapy, the higher the likelihood that he or she will survive without permanent disabil-ity. Since time is so critical, neurologists have created a parameter that helps to quantify how long it takes until a stroke patient receives thrombolytic therapy in a hospital. The ‘door-to-needle time’ is the time that passes from the moment the paramedics carry the patient through the entrance to the hospital until the life-saving thrombolysis is finally administered. “Door-to-needle time is of the utmost importance in patients with ischemic stroke,” says Kaste. “We have shown that saving 15 minutes in door-to-needle time means, on average, one month more of high quality of life for the stroke patient.”

Relocating the CT – a SOMATOM® Definition AS+ with CT Neuro Engine – to the emergency room was one criti-cal measure that Helsinki University undertook to reduce door-to-needle time. “Another very important aspect was hospital pre-notification,” says stroke specialist Atte Meretoja, MD, a young colleague of Kaste’s. Helsinki’s emergency medical service now informs the hospital routinely when-ever a stroke patient is about to be admitted. This allows the CT room to be prepared. And the time before admission is also used to contact rela-tives, to retrieve the patient’s medical history, and to pre-order certain labo-ratory tests.

Transferring knowledge

“The re-allocation of the CT was a crucial step,” says Meretoja. “It didn’t immediately lead to a reduction in door-to-needle time, but it helped us identify other bottlenecks that we could eliminate once the CT was avail-able. We learned, for example, that it was wise to bypass the emergency department cubicle. We transport stroke patients directly into the CT room, carry out a very brief neuro-logical examination and perform the CT examination, immediately after-wards. All in all, these refinements of the admission processes save us an awful lot of time.” In bare figures, Helsinki University Hospital managed to reduce door-to-needle time within ten years from 108 minutes to as little as 20 min.[1] This is more than one hour quicker than in most other parts of the world, including the rest of Europe and the U.S. And stroke care improvements are absolutely cost-effective at Helsinki’s. “In 2007, we paid €11.3 million for 2,000 stroke patients treated in our hospital plus €3.2 million for 6,000 admissions to the neurological ER,” stresses Kaste. “Successful stroke treatment includ-ing stroke unit care and thrombolysis saved us €14.4 million in the costs of chronic institutional care. This means that the neurological ER is actually cost neutral.”

So is it possible to transfer knowl-edge about optimum processes in acute stroke care to other countries? Meretoja has proven that it is. He spent 18 months in Australia as a fellow at University of Melbourne. There, he tested the applicability of the Helsinki protocol in a totally different health-care setting – including the re-allo-cation of a CT into the emergency department. “Within a year, the Hel-sinki result was duplicated. Measures of process improvement similar to those we implemented in Helsinki drove door-to-needle time down from 45 to 25 minutes.”[2] As such, the Helsinki Model represents an enor-mous opportunity to improve stroke care globally.

Helsinki’s emergency medical service now informs the hospital routinely whenever a stroke patient is about to be admitted. This reduces door-to-needle time.

Associate Professor Atte Meretoja, MD, has proven that transferring knowledge about optimum processes in acute stroke care to other countries is possible.

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CT saves critical time

Without imaging, neither Helsinki Uni-versity Hospital nor Royal Melbourne Hospital would have ever achieved this standard, according to Kaste: “CT Imaging for us is really the corner-stone of stroke care. It is where everything starts.” A plain CT is stan-dard for every stroke patient who comes in. It can exclude hemorrhages quickly and cheaply. The MRI is used for selected patients only, pregnant women, for example, or patients with basilar artery thrombosis. The latter have an extended time window for thrombolysis, and the neurologists need to know about the condition of the brain stem before starting treatment.

Younger patients are also candidates for an MRI. They are more likely to suffer from conditions that can be better visualized in the MRI, such as vasculitis, dissections, or cerebral venous sinus thrombosis. “But even in these patients we usually begin with a plain CT,” says Meretoja. “The reality at the moment is that the MRI leads to a considerable delay, and we don’t want that. In acute stroke care, CT is what saves us time and saves the patient’s brain.”

Dynamic CT Angiography

In other words, CT is indispensable to acute stroke care – at least in hospitals where the shortest possible door-to-

They can be used to measure the length of a thrombus, for example, and they give some indications about its consis-tency. Dynamic CT Angiography can also visualize collaterals and thus help the neurologist to evaluate how much brain tissue might be rescued by open-ing the vessel in the region of a blocked artery.[3] “None of this is a standard of care these days. But there are a lot of studies going on with different imag-ing criteria. It will be very exciting to look at all these results,” says Meretoja.

Progress in imaging triggers research

Imaging is also becoming a corner-stone for the second type of patient with acute stroke, those with intra-cerebral hemorrhage. “In these patients, we are still in a situation similar to ischemic stroke 15 years ago,” Meretoja explains. “There is really no proven therapy, except for stroke unit treat-ment and, to a certain degree, blood pressure lowering.”

But there are some exciting new devel-opments in imaging at the moment, and again it is CT technology that is leading the way. “What we have learned in recent years is that hemorrhagic stroke, like ischemic stroke, is a dynamic phenomenon. We now know that intracerebral hemorrhages expand in the early hours after a hemorrhagic stroke in at least 30 percent of patients.” With the help of modern CT technology,

“New technologies such as dynamic CT Angiography

could help pinpoint suitable patients more accurately.”

Associate Professor Atte Meretoja, MD, Helsinki University Hospital, Finland

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needle time is taken seriously. But CT also needs to evolve so that it con-tinues to fulfill the requirements of stroke care in the future. Stroke care is changing. In recent years, intra-arterial clot retrieval devices have become increasingly popular. They are used to extract blood clots and thus open blocked arteries mechani-cally with or without stent implanta-tion. Meretoja: “There are numerous clinical studies at the moment that try to figure out which stroke patients benefit from these methods and which don’t. The global stroke community hasn’t nailed the selection criteria for these interventions yet, but I am pretty sure that we will get there over the next couple of years.”

There is little doubt that CT imaging will play a role here. At the moment, the neurologists at Helsinki University supplement the plain CT examination with a CT Angiography and a CT per-fusion scan in patients who might benefit from intra-arterial therapies. Patients with clear signs of a blocked major vessel are sometimes referred directly to the angiography suite. Around 50 to 100 stroke patients per year from a total of 2,000 receive intra-arterial therapy in Helsinki at the moment.

New technologies such as dynamic 4D CT Angiography called syngo.CT Dynamic Angio could help pinpoint suitable patients more accurately.


“In acute stroke care, CT is what saves us time and

saves the patient’s brain.”

Professor Markku Kaste, MD, Helsinki University Hospital, Finland

interventional therapies, will acute stroke care in the future move in the same direction as therapy in acute myocardial infarction? Will there be the neurological equivalent of a cath lab? A room that combines CT imag-ing and an angiography suite that would allow patients to be treated right away – without any further transport – not only with intravenous thrombolysis but also, if necessary, with interventional therapies?

The jury is still out. “While we still don’t know exactly how many patients benefit from interventional therapies, all this talk of ‘neurological cath labs’ is somewhat speculative,” says Meretoja. “If it turns out that the target group for interventional recanaliza-tion therapy is only five percent of all patients with ischemic stroke, it might not make sense to bring every patient to the angio-suite right away. If the proportion is 15 percent, it might well make sense.”

For the moment, CT imaging to triage patients remains the method of choice to provide for quickest possible stroke care. Nearly a decade after Helsinki University moved its CT to the emer-gency department, the fruits of this ‘revolution by relocation’ are still being reaped. So, it might not have been the final revolution in stroke care. History is ongoing.

neurologists and neuroradiologists are able to identify this subset of patients with ongoing bleedings.

“We use CT Angiography with contrast medium. There are many emerging parameters: We can visualize bleedings outside the vessel and measure the amount and the speed of contrast medium pouring out. We can count the bleeding spots, determine the size of these spots, and much more.” What is still lacking is an established treatment. But studies are ongoing, and it was the advances in CT imaging that really trig-gered this direction in stroke therapy research.[4]

One-stop management of acute stroke

Given that there is so much progress in CT imaging, and traditional medical therapies for stroke patients are increasingly being supplemented by

With syngo.CT Dynamic Angio collateral status in stroke can clearly be visualized and occlusion length efficiently measured. Courtesy of University Hospital Göttingen, Germany

Further Information

www.siemens.com/ ct-clinical-engines

Philipp Grätzel von Grätz, is a medical doctor turned freelance writer and book author based in Berlin, Germany. His focus is on biomedicine, medical technology, health IT, and health policy.

References[1] Meretoja A, Strbian D, Mustanoja S,

Tatlisumak T, Lindsberg PJ, Kaste M. ”Reducing in-hospital delay to 20 minutes in stroke thrombolysis.Neurology. (2012) 79:306-13.

[2] Meretoja A, Weir L, Ugalde M, Yassi N, Yan B, Hand P, Truesdale M, Davis SM, Campbell BC. “Helsinki model cut stroke thrombolysis delays to 25 minutes in Melbourne in only 4 months. Neurology. 2013 Aug 14. [Epub ahead of print]

[3] Frölich AM, Schrader D, Klotz E, Schramm R, Wasser K, Knauth M, Schramm P. ”4D CT Angiography More Closely Defines Intracranial Thrombus Burden Than Single-Phase CT Angiog-raphy. AJNR Am J Neuroradiol. 2013 Apr 25. [Epub ahead of print]

[4] Meretoja A, Churilov L, Campbell BC, Aviv RI, Yassi N, Barras C, Mitchell P, Yan B, Nandurkar H, Bladin C, Wijeratne T, Spratt NJ, Jannes J, Sturm J, Rupasinghe J, Zavala J, Lee A, Kleinig T, Markus R, Delcourt C, Mahant N, Parsons MW, Levi C, Anderson CS, Donnan GA, Davis SM. “The Spot sign and Tranexamic acid On Preventing ICH growth - AUStralasia Trial (STOP-AUST): Protocol of a phase II randomized, placebo-controlled, double-blind, multicenter trial. Int J Stroke. 2013 Aug 26. [Epub ahead of print]



With practices in Mannheim and Ludwigshafen, the Center for Radiological Diagnostics (ZRD) provides care for patients across the entire Rhine-Neckar region (2.3 million inhabitants) and boasts a broad examination spectrum in the fields of radiography, CT, MRI, and nuclear medicine. When the practice on the west side of the Rhine started looking for a replacement for its existing 6-slice scanner, Siemens Healthcare developed a payment plan that allowed

The Center for Radiological Diagnostics (ZRD) in Ludwigshafen, Germany, has been able to significantly expand the range of examinations it offers. The SOMATOM® Perspective 64 not only allows radiologists there to perform cardiac imaging for the first time and to reduce examination times, it also offers the possibility of upgrading to a 128-slice CT scanner in the future.

it to operate a new 64-slice CT for the same monthly price. The ZRD has been using the first SOMATOM Perspective 64 in Germany since January 2013.

Rainer Ulmer, MD, and Attila Sekillioglu, MD, from the ZRD, together with chief radiographer Kornelia Gräf, describe their experiences of transitioning to the new computed tomography scanner, the financial implications, as well as the wider range of diagnostic possibilities.

All-in-one

By Philipp Braune

One motivation for Attila Sekillioglu, MD, (left) and Rainer Ulmer, MD, (right) from ZDR in Ludwigshafen purchasing a SOMATOM Perspective was the cutting-edge technology, offering the perfect combination of straightforward operation, low space requirements, broad technical possibilities – at a reasonable price.


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Why did you decide to replace your 6-slice CT with a SOMATOM Perspective 64?

Rainer Ulmer, MD: One initial motivation was the cutting-edge technology used in the new system. And since we were due to renew our old scanner after six years anyway, we also wanted to expand our range of examinations in the field of cardiology.

Attila Sekillioglu, MD: Up to now, devices for cardiac imaging have been in a completely different price category. But the SOMATOM Perspective really is an all-in-one sys-tem: It offers the perfect combination of straightforward operation, low space requirements, broad technical possi-bilities – and at a reasonable price. For us, this was the smart way to conquer a new market.

How was the process of switching over from one system to the other?

Ulmer: We really had a very short changeover time and not much had to be moved around in the actual room. Once we disconnected the old system, the new system was in place within two weeks. If we hadn’t also had to carry out some renovations that were due, we could have easily managed the changeover within a week.

What were your first impressions?

Sekillioglu: I thought it looked nice and compact. We managed to install a new high-end system in the old room without having to change it; the mood lighting really improves the space. It has a completely different atmosphere, not cold and clinical but really quite appeal-ing. The patients and the team are very happy with it.

Kornelia Gräf: The patients are always very nervous when they enter the room, but they tend to notice the lighting even if they don’t realize that it’s a new device. They often comment on the blue or red light, which helps to relax the situation.

Ulmer: Operation is now much easier thanks to the larger key panel, which is especially helpful when you’re wearing gloves. The LCD monitor above the gantry is also great for reading the patient name and vital information.

What are the most important improvements that the SOMATOM Perspective 64 has brought to your practice?

Ulmer: The speed of the system helps us in all areas. In abdomen and thorax examinations, patients simply have to breathe in for a few seconds. It is also crucial that we are able to reduce radiation down to a minimum during interventions – in periradicular therapies for example – so that we can only see the bones and needles. The system does this automatically in some cases.

And this results in a clear reduction in dose?

Ulmer: Yes, by at least a third. This is also important to the patients, since they don’t understand many of the other technical details – they often ask about the radia-tion dose.

Gräf: We hear questions about radiation all the time. The dose value is a hot topic for patients. This is why we use the SAFIRE algorithm to reduce the dose as far as possible, alongside other techniques. I think a low radiation dose makes a significant difference to the patients, and this is something that makes a practice stand out.

Diagnosing using the syngo®.via software enables the ZRD to benefit from numerous automated processes and a high degree of efficiency.

Rainer Ulmer, MD, Center for Radiological Diagnostics (ZRD)

in Ludwigshafen, Germany

“The speed of the SOMATOM Perspective helps us in all areas.”


Could you give a concrete example to explain how the SOMATOM Perspective has expanded your range of examinations?

Sekillioglu: Due to the new system, we now have inten-sive cooperation with colleagues in cardiology who per-form transcatheter aortic valve implantations. With these TAVIs, the valve is inserted through the groin in a mini-mally invasive procedure. The planning of the operation therefore requires a detailed image of the heart, on one hand, and also a complete scan of the overall area up to the groin so that we can determine whether the arteries in the groin and the aorta are big enough for the valve to pass through. Our task is then to provide high-quality images and measurements of the heart and the branches of the coronary arteries all the way through to the groin. With the new system, we are optimally equipped to do this.

Were there particular cases where the advantages of the new system became immediately clear?

Ulmer: In one case, we discovered a pulmonary embolism. The patient would otherwise have died. He was complain-ing of pain in his right leg and the internist who referred him suspected that the problem was in the patient’s spine. We performed a complete examination using the new sys-tem and the monitor showed straightaway that he had a fulminant pulmonary embolism on both sides, which had been caused by a thrombosis in his leg. I called an ambu-lance immediately.

Sekillioglu: In the past, we had to decide in advance whether to perform a standard examination of the thorax, or whether to focus on the arteries or veins.

With the previous system, we had a specific examination procedure for detecting a pulmonary embolism, which differed from the standard examination for the thorax. We now carry out the examination using a procedure that can answer all of our questions – even those asked retro-spectively. We no longer have to make trade-offs between examination time, image resolution, the amount of con-trast medium, and the radiation dose. This is a key advan-tage for us.

To what extent has the examination time been reduced by the new system?

Gräf: By around fifty percent. In fact, the only limiting factor is the setting-up time, as before. The examinations themselves are really surprisingly quick.

What is your impression of the syngo.via software?

Ulmer: Since we were already familiar with the interface from using syngo, the transition was easy. However, we soon noticed that the software has actually become even more user-friendly. There are more automated processes that support our work; you can just tell that syngo.via has really been designed for practitioners.

Would you recommend purchasing a SOMATOM Perspective to colleagues?

Sekillioglu: Yes, absolutely. When considering a new CT system for your practice, you have to take so many elements into account: Do you need to carry out modifi-cations, make structural changes, or replace the air con-ditioning system? Can you afford to procure a high-end system? None of these were an issue with the SOMATOM Perspective. The device fit into the previous space and was installed very quickly. It is now part of the practice and I notice how much I enjoy the examinations simply because I can do so much more.

Ulmer: It is also an investment in the future. With the SOMATOM Perspective, we have managed to expand into the field of cardiology without having to make large advance payments. The revenue from public healthcare has decreased by over fifty percent in the past decade in Germany, and it is difficult to anticipate what will happen in the future. It would have been too great a risk to invest into a high-end system specifically for cardiology. The SOMATOM Perspective provided an economically viable yet future-oriented option. With the 64-slice configuration, we can deliver high-quality images for cardiology. If demand increases, we can upgrade to the 128-slice version for a reasonable price.

The Center for Radiological Diagnostics (ZRD) provides care for patients across the entire Rhine-Neckar region with its 2.3 million inhabitants.

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When Space is at a Premium – Compact High Quality Scanning By Tomoko Fujihara, Computed Tomography, Siemens Healthcare, Tokyo, Japan

Masaaki Senoo, MD, director of Senoo Hospital in Hiroshima understands the problems of limited space: The scanning room at his hospital is only 12.8 square meters. When considering purchasing a new, more powerful CT, the SOMATOM® Perspective 64-slice configuration appeared to be the ideal option: A CT that can be installed easily – even in compact spaces – while still offering efficiency, low dose, and high image quality. Senoo Hospital was the first in Japan to install the scanner. Masaaki Senoo, MD, and chief radiological technologist Toshihiko Oguma reported on their experience of installation and initial use.

CT for cardiac scanning

Senoo Hospital located in Hiroshima, Japan, is run accord-ing to the principle of “patient-centered medicine with respect for each individual”. This chimes well with Siemens’ concept of patient-centered device development and so when the time came to decide on a new CT scanner, hos-pital director Masaaki Senoo looked immediately to the SOMATOM range. Having heard positive feedback from nearby hospitals and from his colleagues on Siemens devices, the decision came down to a 16-slice or 64-slice CT scanner. One opinion was that the 16-slice was adequate in terms of cost performance and installation space, but the 64-slice would be much better suited for heart CT scans.

SOMATOM Perspective

While options were still being considered, the Siemens SOMATOM Perspective 64-slice configuration came onto the market – at just the right time to meet the needs of Senoo Hospital. Director Senoo explained, “Above all, the device itself is compact and it offers a 64-slice CT scanner with superior cost performance.” It was precisely the factor of compact size versus powerful performance and efficient running costs that finally sealed the decision.

Installation in small space

In the past, maintaining a 64-slice CT scanner in a limited space was unthinkable. Due to a new space-saving design, the SOMATOM Perspective could be installed at Senoo Hospital without any need for room modifications or power source installation work. Once it was up and running in the scanning room, staff were surprised again at the truly compact size. “It even feels smaller than the single slice CT device we were using before,” said Senoo.

Initial experience and advantages

In addition to the advantage of its small size, staff soon noticed the quietness of the SOMATOM Perspective. Work-flow has also become noticeably more efficient with a reduc-tion in the time required for the examination. Patients, too,

appreciate not having to wait long for their CT examination. Both Director Senoo, MD, and his chief radiological tech-nologist, Oguma, agree that it was a choice well made: If they had to decide again which high-power CT best fit their needs, they would choose the SOMATOM Perspective without a shadow of a doubt.

The installation diagram shows the limited space for a new CT system at Senoo Hospital. However after the SOMATOM Perspective 64-slice configu-ration was installed, the staff were very surprised at its compact size.

For Masaaki Senoo, MD, director of Senoo Hospital in Hiroshima (right) and chief radiological technologist Toshihiko Oguma (left) it was precisely the factor of compact size versus powerful performance and efficient run-ning costs that confirmed the decision in favor of a SOMATOM Perspective 64-slice configuration.

Operations Room

2.85 m

4.50 m

Scanning Room

SOMATOM Perspective


treated with percutaneous transluminal coronary angioplasty and stenting of the mid LAD with an excellent angio-graphic result (Fig. 4).

CommentsCTA can detect calcified plaques of the coronary arteries; however, the severity of the stenosis might not be interpretable if the coronary artery is extensively calcified. Adenosine-Stress Dynamic Myocardial CT Perfusion per-mits evaluation of the hemodynamic significance caused by the stenosis, and assists in the decision-making pro-cess for optimal patient treatment.

DiagnosisCTA images showed multiple calcified plaques in all three coronary arteries, most extensively in the proximal and mid segments of the LAD (Figs. 1 and 2). It was therefore impossible to determine conclusively the severity of the stenosis. After the administra-tion of adenosine, the ECG showed no significant abnormality at all.

Stress perfusion images (Fig. 3) showed a significant reduction in the myocardial blood flow in the LAD territory, compared with the CFX or RCA territories. The findings depicted a significant ischemia in this region.

In the cath lab, the mid LAD stenosis was confirmed and the patient was

History A 66-year-old male patient, complain-ing of evolutive exertional dyspnea for the past few months, presented himself for a cardiac check-up. He was once a heavy smoker but has not smoked for the past 7 years. He had moderate dyslipidemia, controlled by statin. The classical examinations, carried out at the consultation, were normal with exception of the bicycle-stress test, which showed objective dyspnea at the peak exercise of 110 watts without ECG abnormalities. Since the stress test was non-conclu-sive, CTA was proposed to complete the examinations.

Case 1

Myocardial Ischemia Assessment using Adenosine-Stress Dynamic Myocardial CT PerfusionBy Dikraniant T.¹, MD; Ghijselings L.², MD; Vargas Lobos M.², MT; Genard L.², MT; Derauw O.², MT; Deconinck D.², MT

1 Internal Medicine Department-Cardiology, Europa Clinics, Brussels, Belgium 2 Medical Imaging Department, Europa Clinics, Brussels, Belgium

VRT (Fig. 1A) and curved MPR (Fig. 1B) images demon-strate the extensively calcified LAD.

1

1B1A

Clinical Results Cardiovascular


Examination Protocol

Scanner SOMATOM Definition Flash

Scan area Heart

Scan mode VPCT

Scan length 70 mm

Scan direction Cranio-caudal

Scan time 31 s

Tube voltage 100 kV

Tube current 125 eff. mAs

Dose modulation CARE Dose4D

CTDIvol 78.2 mGy

DLP 562 mGy cm

Effective dose 7.9 mSv

Rotation time 0.28 s

Slice collimation 32 x 1.2 mm

Slice width 3 mm

Reconstruction increment

2 mm

Reconstruction kernel

B23f

Contrast

Volume 50 mL contrast + 40 mL saline

Flow rate 6 mL/s

Start delay Determined by test bolus

2A 2B

4B

Curved MPR images show multiple calcified plaques in the Cx (Fig. 2A) and RCA (Fig. 2B).

Perfusion images reveal myocardial perfusion defects (in blue) in the LAD territory.

Angiographic images confirmed the mid LAD stenosis (Fig. 4A). The patient was treated with PTCA and stenting of the mid LAD with an excellent angiographic result (Fig. 4B).

2

3

4

Cx RCA

3

4A

Cardiovascular Clinical Results


The use of a lower tube voltage (70 kV) scanning protocol leads to a significant increase in mean attenuation and mean contrast enhancement of the coronary arteries as well as significantly higher image noise. The contrast enhancement allows minimizing the amount of con-trast media and the image noise can be solved perfectly with the application of SAFIRE technique. Dual Source CT Flash mode with very high pitch spiral scan-ning, can not only shorten acquisition time, but also reduce the radiation exposure and the necessary amount of contrast medium (in this case, 0.39 s, 0.19 mSv and 45 mL).

CommentscCTA is a valuable non-invasive imag-ing examination with high diagnostic accuracy. Technological advances allow not only dose reduction but also improvement in the image acquisi-tion. The SOMATOM Definition Flash scanner has several technical advan-tages, including the Stellar detector and Sinogram Affirmed Iterative Reconstruction (SAFIRE) – the first raw data-based iterative reconstruc-tion application. Both make it possible to use lower tube voltage in cCTA examinations with excellent image quality.

History A 61-year-old female patient was referred to the hospital complaining of chest pain and shortness of breath. A coronary CT Angiography (cCTA) was requested to rule out coronary artery disease.

DiagnosisThe CT images demonstrated a mild stenosis, from soft plaque, in the proximal left anterior descending artery (LAD), and a myocardial bridge in the middle LAD with no evidence of stenosis. The circumflex (Cx) was small in caliber but showed no evi-dence of stenosis. The right coronary artery (RCA) appeared normal.

Case 2

Coronary CTA with Reduced Contrast and Radiation Dose of 0.19 mSvBy Yining Wang, MD, Jian Cao, MD

Department of Radiology, Peking Union Medical College, Beijing, P.R. China



Scan area Heart Slice collimation 128 × 0.6 mm

Scan length 115 mm Slice width 0.75 mm

Scan direction Cranio-caudal Temporal resolution 75 ms

Scan time 0.39 s Reconstruction increment 0.5 mm

Tube voltage 70 kV Reconstruction kernel I26f

Tube current 270 eff.mAs Patient heart rate 57 – 69 bpm

CTDIvol 0.78 mGy Contrast

DLP 13.7 mGy cm Volume 45 mL

Effective dose 0.19 mSv Flow rate 3.5 mL/s

Rotation time 0.28 s Start delay Test Bolus Peak Trigger + 21 s

Pitch 3.4



Curved MPR (Fig. 1A), MIP (Fig. 1B), and VRT (Fig. 1C) images demonstrate the LAD with mild stenosis (arrows) from soft plaque, and a myocardial bridge (arrowheads) in the middle LAD with no evidence of stenosis. The Cx (dashed arrow) and the RCA (double arrows) appear to be normal, although the Cx is small in caliber.

1

1A 1B

1C


In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task.


hemodynamically insignificant and are usually found incidentally.[2, 3] Congenital abnormalities of the coro-nary arteries are an uncommon but important cause of chest pain. Rare hemodynamic abnormalities may lead to sudden cardiac death. An Electro-cardiographic-(ECG) gated multi detector CT is superior to conventional angiography in delineating the ostial origin and the path of an anomalous coronary artery. Familiarity with the CT appearances of various coronary artery anomalies and an understand-ing of the clinical significance of these anomalies are essential for a correct diagnosis and planning patient treat-ment. Bicuspid aortic valves are the most common cardiac valvular anom-aly, occurring in 1–2% of the general population. This is twice as common in males as in females.[4]

History A 43-year-old male patient, clinically diagnosed with aortic stenosis, was referred for pre-operative evaluation. He complained of restlessness, chest pain, breathlessness, and heart palpi- tations.

DiagnosisThe CT images revealed calcified bicuspid aortic valves with severe aortic stenosis and left ventricular hypertrophy (Figs. 1 and 2) associated with ischemic changes in the myocar-dium. There was additional evidence that the right conus artery arose from the right aortic sinus and communi-cated with the main pulmonary artery anteriorly (Fig. 3). These findings suggested an anomalous coronary artery fistula. The remainder of the coronary arterial system and cardiac anatomy was normal. The patient suc-cessfully underwent an aortic valve replacement with a mechanical pros-thesis and suturing of the coronary artery fistula.

CommentsCoronary-pulmonary artery fistulas are uncommon cardiac anomalies, usually congenital, with an estimated incidence of 0.002% in the general population.[1] Most coronary-pulmo-nary artery fistulas are clinically and

Case 3

Bicuspid Aortic Valve with Anomalous Coronary Artery Fistula – A Rare Incidental CoincidenceBy Kamal K. Sen MD, Professor & Head, Sudhakar P. DMRD, Senior Resident, Kannan G. MBBS, Junior Resident

Department of Radiology & Imaging, PSG Institute of Medical Sciences & Research, Coimbatore 64004, Tamil Nadu, India


Scanner SOMATOM Definition Edge

Scan mode ECG-gated spiral scan

Scan area Heart

Scan length 172.5 mm


Scan time 7.5 s

Tube voltage 100 kV

Tube current 79 eff. mAs


Pitch 0.17


Slice width 0.6 mm


0.3 mm

Temporal Resolution

75 ms


I26f, SAFIRE

CTDIvol 14.69 mGy

DLP 286 mGy cm

Effective Dose 4 mSv

Contrast

Volume 70 mL

Flow Rate 5.5 mL/s

Start delay 6 s

References[1] Burch GH, Sahn DJ. Congenital coronary

artery anomalies: the pediatric perspec-tive. Coron Artery Dis 2001;12:605–16.

[2] A. Tomasian,M. Lell, J Currier,J Rahman, M.S.Krishnam, Coronary artery to pulmonary artery fistulae with multiple aneurysms... The British Journal of Radiology, 81(2008), e218–e220.

[3] A.R Zeina, J Blinder, U Rosenschein E Barmeir. Coronary-pulmonary artery fistula diagnosed by multidetector computed tomography: Postgrad Med J. 2006 July; 82(969): e15.

[4] Tzemos N, Therrien J, Yip J et al. (September 2008). “Outcomes in adults with bicuspid aortic valves”. JAMA 300 (11): 1317–132



A non-enhanced CT axial image shows calcification in the bicuspid aortic valve.

1

1

VRT images reveal the origin (dashed arrows) and the course (arrows) of the coronary artery fistula.

3

3A

3B

3C

2

Post-contrast cCTA image demonstrates the aortic stenosis, the left ventricular hypertrophy and a section of the conus artery fistula course (arrow).

2


shown in Table 1. Time to Drain (TTD) and Time to Start (TTS) were also sig-nificantly increased (Fig. 5A).

A direct bypass procedure by anasto-mosis of the left superficial temporal artery (STA) to the middle cerebral artery (MCA) was performed (Fig. 4).

After successful surgery, VPCT images showed a partially restored reserve capacity in the left MCA territory indi-cated by normalized CBF and dimin-ished increase of CBV and MTT as shown in Table 2. The increase of TTD and TTS also diminished in magnitude and spatial extent (Fig. 5B).

The patient recovered completely from his speech impediment. His right arm, however, remained weaker than the left, but muscle strength improved from III (at admission) to V (at discharge).

CommentsMoyamoya disease is characterized by a progressive steno-occlusive vasculopathy of the terminal portion of the internal carotid artery and its main branches. It is associated with the development of dilated, fragile collateral vessels at the base of the brain, which are termed “Moyamoya vessels”. These collateral vessels have the appearance of a “puff of smoke”. Most patients suffer from recurrent ischemic attacks. Dynamic VPCT can be used to evaluate the details of cerebral hemodynamic changes in

HistoryAn 11-year-old boy was admitted to the hospital complaining of progres-sive weakness of the right arm for the past 6 days and unclear enunciation, accompanied by nausea and vomiting for the past 2 days. An MR examina-tion raised questions as to a cerebral infarction of the left parietal and frontal lobe, which was confirmed by a CT 11 days later (Fig. 1). DSA images (Fig. 2) indicated the possibility of the Moyamoya disease. CTA and Vol-ume Perfusion CT (VPCT) examina-tions were ordered for pre-operative planning.

DiagnosisPrior to the operation, CTA images (Fig. 3) showed that the ACA A1 seg-ment was occluded on the left, and had severe stenoses on the right. The MCA M1 segments were highly stenosed on both sides. The bilateral vertebral arteries, the posterior cere-bral arteries (PCA), and the basilar artery were unusually enlarged. The left posterior communicating artery (PCOM) was noticeably dilated in com-parison with the one on the right.

VPCT images showed an exhausted reserve capacity in the left MCA territory indicated by the increase of cerebral blood volume (CBV), the reduction of cerebral blood flow (CBF) and the strong increase of mean tran-sit time (MTT) (above the frequently used penumbra threshold of 145% for relative MTT used in stroke) as

Case 4

Dynamic Volume Perfusion CT in a Case of Childhood Moyamoya Disease before and after Surgical RevascularizationBy Zhenlin Li, Chief Technologist, Prof. Bin Song, MD, Jin Zhao, Technologist, Kai Zhang, Technologist, Bing Wu, MD, Xi Zhao*, MD

Department of Radiology, Huaxi University hospital, Chengdu, Sichuan, P.R. China *Siemens Healthcare China



Scan area Head

Scan length 100 mm

Scan direction Adaptive 4D Spiral

Scan time 36 s

Tube voltage 70 kV

mAs per image 100

Dose modulation n. a.

CTDIvol 56.42 mGy

DLP 665 mGy cm



Pitch 0.55


Slice width 3 mm


2 mm


H20f

Contrast

Volume 32 mL + saline

Flow rate 4.0 mL/s

Start delay 5 s

patients with Moyamoya disease before and after surgery. Cerebral CTA is useful for assessing the abnormali-ties of the intracranial arteries and the patency of bypass grafts.

Clinical Results Neurology


Left Right Diff.

CBF 47.7 51.7 -8%

CBV 3.39 2.70 +26%

MTT 5.19 3.38 +54%

Table 1: Pre-operative – Exhausted reserve capacity indicated by increase of the CBV, the reduction of CBF and the strong increase of MTT (54% increase is above the frequently used penumbra threshold of 145% for relative MTT used in stroke).

Left Right Diff.

CBF 54.5 53.4 +2%

CBV 3.32 2.80 +16%

MTT 4.19 3.25 +29%

Table 2: Post-operative – Partially restored reserve capacity indicated by normalized CBF and diminished increase of CBV and MTT.

1

3D TTD (Fig. 5A) and TTS (Fig. 5B) maps showed the full extent of the hemodynamic disturbance before surgery and the significant postoperative improvement.

5The post-operative overlaid CTA images showed the course of the STA (arrow) MCA bypass (arrowheads).

4

MR images acquired at admission showed infarction of the left parietal and frontal lobe. CT images acquired 11 days later confirmed the infarction although with very subtle signs (arrows).

1 Pre-operative DSA images demon-strated that the ACA A1 segment was stenosed on the right (R, arrow), and occluded on the left (L, arrow). The MCA M1 segments were highly stenosed on both sides (arrowheads). The dilated PCOM and the collateral vessels from PCA to ACA were also seen on the left (L, dashed arrow).

2 Pre-operative CTA images demon-strated the vascular changes of ACA A1 and MCA M1 as described in Fig. 2. In addition, it also showed that the bilateral vertebral arteries (arrows), PCA (arrow-heads), basilar artery (curved arrow) and the left PCOM (dashed arrow) were unusually dilated.

3

3A

3B

1 2

4 5A 5BPre

LR

Post Pre Post

Neurology Clinical Results



Case 5

Differentiating an Intracranial Hemorrhage from Iodine in Acute Stroke after Intra-arterial RecanalizationBy Alida A Postma, MD, Paul AM Hofman, MD, Joachim E Wildberger, MD

Dept. of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands

Non-contrast CT axial images demonstrated a small focus of

subarachnoid hemorrhage in a right parietal sulcus (Fig. 1A, arrows), and a faint loss of gray-white matter differen-tiation with effacing of the sulci in the right (MCA) territory (Fig. 1B).

1

1B

1A

2B

VRT images show an occluded right proximal MCA (Fig. 2A, arrow), and a successful recanalization (Fig. 2B).

2

2A

MCA (Fig. 2A). Perfusion CT (Fig. 3) revealed a mismatch of reduced cere-bral blood flow (CBF) and cerebral blood volume (CBV) which indicated the existence of a penumbra. Time to drain (TTD), mean transit time (MTT) and time to peak (TTP) were increased indicating a delayed blood supply.

Following a successful intra-arterial thrombectomy, a large mixed hyper-dense area in the cortical and subcor-tical zones in the MCA territory, at the level of the basal ganglia, was shown in the mixed images (comparable to conventional CT images) of a Dual Energy (DE) CT scan (Fig. 4). This posed a critical question – is it a hemorrhage as a reperfusion complication in a patient with pre-IAR intracranial hem-orrhage? Or is it an iodine extravasa-tion in the brain parenchyma due to

History

A 57-year-old male patient was pre-sented to an external hospital with a left-sided grade 1 paralysis. This resulted from a large infarction in the right middle cerebral artery (MCA) territory. Treatment with intravenous rtPA was started but then suspended due to the suspicion of a small hem-orrhage in the non-contrast CT. The patient was referred to a tertiary center for intra-arterial recanalization (IAR).

Diagnosis

The non-contrast CT images demon-strated a small focus of subarachnoid hemorrhage in a right parietal sulcus (Fig. 1A). A faint loss of gray-white matter differentiation and effacing of the sulci in the MCA territory was seen (Fig. 1B). CTA images showed an occlusion of the right proximal

the breakdown in the blood brain bar-rier in a patient who had received con-trast during IAR? DE scan was helpful for differential diagnosis. The hyper-density in the right MCA territory at the level of basal ganglia was shown in the iodine overlay maps (IOM) and the iodine images, but was not seen in the virtual non-contrast (VNC) images (Fig. 4). Therefore, a contrast extra-vasation was confirmed and a hemor-rhage was excluded. Consistent with the pre-IAR scan, the small focus of hyperdensity in the subarachnoid space of a right parietal sulcus (Fig. 5) appeared again in the mixed and VNC images with only a minor density increase, but was not seen in the IOM and the iodine images, suggesting a remaining hemorrhage.

Follow-up CTs, at day 1 and day 5, showed no signs of hemorrhage in the MCA territory (Fig. 6), which confirmed the interpretation of contrast extra-vasation due to the breakdown of the blood brain barrier. At discharge, the patient had partially recovered but there remained a grade 4 paresis of the right arm and leg as well as a dis-crete facial asymmetry.

Comments

In patients undergoing IAR, hemor-rhages are feared complications and therefore a post-procedural CT is stan-dard practice. However, iodine had been administered in this patient group during the intervention. Therefore, the differentiation of intracranial hemor-rhage from a contrast extravasation is difficult with conventional CT within the first 24 hours after IAR due to the similarity of the Hounsfield densities of hemorrhages and iodine.

Clinical Results Neurology


CBF

TTD

CBV

MTT

MIP

TTP

3

Volume-perfused CT images show a mismatch between the reduced CBF and CBV representing an existing penumbra (MIP, in yellow) in the right MCA territory. TTD, MTT and TTP are elevated, demonstrating a delayed blood supply.

3

4

lodineVNC

IOM

Follow-up non- contrast CT, at day 1,

shows an infarction in the right MCA territory (Fig. 6B), despite success-ful recanalization. No hemorrhage was present.

6

6A

6B

DECT images show the hyperdensity in the subarachnoid space (arrows) in the mixed and the VNC images, but not in the IOM and the iodine image, suggestive of hemor-rhage, consistent with the pre-IAR scan.

5

IOM

VNC lodine

Mixed5

On the other hand, iodine and hemor-rhages have a different attenuation at lower kV levels. This is used in 3-material decomposition after scan-ning at two different energy levels (80 kV / Sn 140 kV). Using the “Brain hemorrhage” application, the differen-tiation between iodine and hemor-



Scan area Head

Scan mode Dual Energy (post IAR)

Scan length 155 mm


Scan time 9 s

Tube voltage 80 kV / Sn 140 kV

Tube current 392 / 196 mAs


CTDIvol 36.43 mGy

DLP 615 mGy cm

Effctive dose 1.29 mSv

Rotation time 0.5 s


Slice width 1 mm


1 mm


D26f

rhages becomes possible. In this patient, hyperdense areas were pres-ent after recanalization and a large hemorrhage was feared. However, IOM convincingly showed the density to be iodine, while VNC showed no signs of hemorrhage in this area. Therefore, an antiplatelet therapy

could be continued. DECT is helpful in determining the nature of a hyper-dense area, by discriminating between hemorrhages or iodine. This aids in the clinical decision-making and allows for early adjustment of the patient’s therapy treatment.

DECT images show the hyperdensity in the right MCA territory at the level of basal ganglia in the mixed, IOM, and iodine images, but not in the VNC image, suggestive of contrast enhancement due to breakdown of the blood brain barrier.

4

Mixed

Neurology Clinical Results


DiagnosisThe examination was performed on a SOMATOM Definition AS 64 sliding gantry system, equipped with CARE kV. The images were acquired at 100 kV, as suggested by the scan-ner, resulting in a total DLP of only 329 mGy cm (4.6 mSv). Image quality was excellent in all anatomical areas, with a high level of enhancement in all parenchymal organs and vessels. Hereby, the diagnosis of a splenic rupture with free abdominal fluid was reliably made. Injuries of other parenchymal organs, vessels, the lungs and the spine were as well confidently excluded. The patient was immedi-ately transferred to the operating room.

HistoryAn 11-year-old girl had fallen off a horse and had been hit by the horse’s hoof. The paramedics found her complaining of abdominal pain and with a tense abdominal wall. She was transferred to the hospital’s trauma room. Here an interdisciplinary team of pediatricians, anesthesiologists, trauma and abdominal surgeons as well as radiologists examined the young patient according to standard-ized algorithms, based on the ATLS (advanced trauma life support) guide-lines. An early abdominal ultrasound revealed free abdominal fluid espe-cially in the Koller’s and Morrison’s pouch. This led to the decision to con-duct a thoraco-abdominal contrast-enhanced trauma CT.

Case 6

Diagnosis of Splenic Rupture in an 11-year-old Girl using a Sliding Gantry CTBy Claudia Frellesen, MD, J. Matthias Kerl, MD, Thomas J. Vogl, MD, Ralf W. Bauer, MD

Department of Diagnostic and Interventional Radiology, Goethe University, Frankfurt, Germany

View of our trauma room with a sliding gantry solution. In the back, the sliding gantry is in its normal position in the standard CT examination room. The CT suite and the trauma room are separated by a sliding X-ray-proof (background) door. If CT is required for a trauma patient, the door opens and the gantry slides over. The patient is scanned without the need for any further relocation.

CommentsBlunt abdominal trauma can lead to life-threatening injuries. Integrating whole body CT early in the manage-ment of polytrauma patients results in improved survival and facilitates early triage for adequate therapy.[1] In the previous trauma room solution, with a stationary conventional 16-slice scan-ner, the patient needed to be relocated from the trauma room to the CT suite and back. This caused delay in diagno-sis and treatment and bore the risk of dislocating tubes and lines and aggra-vating spine injuries. The current two room sliding gantry solution elegantly overcomes these drawbacks. The trauma patient remains stationary on the examination table and the gantry slides over if required. Another benefit of this solution is that the down time of the standard CT suite and subsequent delays for regularly scheduled in- and outpatients can be reduced to a mini-mum and daily throughput increases. Together with the state-of-the-art dose reduction strategies, such as CARE kV and SAFIRE, image quality improves while dose exposure is effectively reduced. The precision of the system is equivalent to a conventional CT with stationary gantry and moving table, facilitating submillimeter high-resolu-tion imaging e.g. of the temporal bone as well as the coronary arteries with a temporal resolution of 150 ms.

References[1] Huber-Wagner S, Lefering R, Qvick L-M,

et al. Effect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study. Lancet. 2009;373:1455–61

Clinical Results Acute Care


1

Excellent image quality in the upper abdomen with very good iodine enhancement at 100 kV and no artifacts compro-mising the diagnosis of splenic rupture. Pancreas, kidneys, and liver appear normal.

1

Coronal 3 mm MPR shows the ruptured spleen and lots of free abdominal fluid while liver and kidneys appear normal. There is no detectable difference in image quality to a stationary gantry with moving table.

2

Excellent image quality to confirm no spine injury.

3

2

3


Scanner SOMATOM Definition AS 64 Sliding Gantry System

Scan area Chest / Abdomen Rotation time 0.5 s

Scan length 63 cm Pitch 1.2

Scan direction Cranio-caudal Slice collimation 64 x 0.6 mm

Scan time 12 s Slice width 1.0 / 5.0 mm

Tube voltage 100 kV Reconstruction increment 0.5 / 5.0 mm

Tube current 261 mAs Reconstruction kernel B30f, B60f, B75f

Dose modulation CARE Dose4D Contrast

CTDIvol 5.75 mGy Volume 75 mL

DLP 329 mGy cm Flow rate 2 mL/s

Effective dose 4.6 mSv Start delay 70 s

Acute Care Clinical Results


CTPA (Fig. 2). The global pulmonary perfused blood volume (PBV) was 27%. For comparison, figure 3 dem-onstrates homogenous pulmonary perfusion and normal PBV in a patient without pulmonary embolism.

CommentsThe “Lung PBV” application of the syngo.CT DE Lung Analysis software allows for an automated quantifica-tion of pulmonary perfused blood volume as a surrogate for pulmonary perfusion. PBV values are calculated by relating the pulmonary parenchy-mal iodine content to the enhance-ment of a reference input vessel. In addition to a global analysis, PBV val-ues are also generated for each lung as well as for the upper, middle and lower zones of each lung separately, thereby demonstrating the regional distribution of pulmonary perfusion abnormalities. Age-specific norm val-ues for pulmonary PBV have recently been published.[1] PBV quantification can be used to assess the severity of an acute pulmonary embolism [2–4] and the regional distribution of pul-monary perfusion abnormalities in emphysema.[5]

History

A 75-year-old male patient presented to the emergency department com-plaining of a sudden onset of severe dyspnea and chest pain. The patient had a history of prostate cancer. A physical examination revealed that the patient was normotensive (118/60 mmHg), tachycardic (93 bpm) and his oxygen saturation was 94% at room air. Troponin I serum levels (0.46 ng/mL) as well as D-dimers plasma levels (21.5 mg/L) were ele-vated. The patient was referred to the radiology department for a Dual Energy CT pulmonary angiography (CTPA) to rule out pulmonary embolism.

DiagnosisThe CTPA demonstrated filling defects in both the left and right main pul-monary arteries as well as bilaterally in the lobar, segmental and sub-seg-mental pulmonary arteries (Fig. 1). This confirmed the diagnosis of severe acute pulmonary embolism. Multiple wedge-shaped parenchymal perfusion defects were visualized in both lungs on the iodine distribution maps derived from the Dual Energy

Case 7

Automated Quantification of Pulmonary Perfused Blood Volume in Acute Pulmonary Embolism using Dual Energy CTPABy Felix G. Meinel, MD, Anita Graef, MD and Thorsten R. C. Johnson, MD

Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Germany

References[1] Meinel FG, Graef A, Sommer WH,

Thierfelder KM, Reiser MF, Johnson TR. Influence of vascular enhancement, age and gender on pulmonary perfused blood volume quantified by dual-energy-CTPA. Eur J Radiol. May 24 2013.

[2] Nagayama H, Sueyoshi E, Hayashida T, Ashizawa K, Sakamoto I, Uetani M. Quan-tification of lung perfusion blood volume (lung PBV) by dual-energy CT in pulmonary embolism before and after treatment: preliminary results. Clin Imaging. May-Jun 2013;37(3):493-497.

[3] Meinel FG, Graef A, Bamberg F, et al. Effectiveness of Automated Quantification of Pulmonary Perfused Blood Volume Using Dual-Energy CTPA for the Severity Assessment of Acute Pulmonary Embolism. Invest Radiol. Mar 20 2013.

[4] Sueyoshi E, Tsutsui S, Hayashida T, Ashizawa K, Sakamoto I, Uetani M. Quan-tification of lung perfusion blood volume (lung PBV) by dual-energy CT in patients with and without pulmonary embolism: preliminary results. Eur J Radiol. Dec 2011; 80(3):e505-509.

[5] Meinel FG, Graef A, Thieme SF, et al. Assessing pulmonary perfusion in emphysema: automated quantification of perfused blood volume in dual-energy CTPA. Invest Radiol. Feb 2013;48(2):79-85.

Clinical Results Pulmonology


1A 1B

2A 2B

3A 3B

The CTPA images demonstrate filling defects in both the left and right main pulmonary arteries as well as bilaterally in the lobar, segmental and sub-segmental pulmonary arteries.

1

Multiple wedge-shaped parenchymal perfusion defects are visualized in both lungs on the iodine distribution maps derived from the Dual Energy CTPA. The global pulmonary perfused blood volume (PBV) is 27%.

2

Normal PBV in a patient without pulmonary embolism demonstrates homogenous pulmonary perfusion. The global pulmonary perfused blood volume (PBV) is 101%.

3



Scan area Thorax / Chest Rotation time 0.28 s

Scan length 313 mm Pitch 0.55

Scan direction Caudo-cranial Slice collimation 64 x 0.6 mm

Scan time 8.5 s Slice width 1.5 mm

Tube voltage 100 kV / Sn 140 kV Reconstruction increment 1 mm

Tube current 145 eff. mAs / 120 eff. mAs Reconstruction kernel Q30f

Dose modulation CARE Dose4D Contrast 370 mg/mL

CTDIvol 11.9 mGy Volume 70 mL contrast + 100 mL saline

DLP 391 mGy cm Flow rate 4 mL/s

Effective dose 5.47 mSv Start delay Bolus triggering in the pulmo-nary trunk with a threshold of 100 HU and an additional delay of 7s

Pulmonology Clinical Results


tions. Her family history was unre-markable. An ultrasound examination was primarily performed for the kid-neys and bladder. There were no signs of either hydronephrosis or calculi in the urinary system. A Dual Energy (DE) CT was then ordered for further clarification.

History A 27-year-old female patient pre-sented herself to the hospital with acute flank pain. She complained of recurrent back pain for the past two years and was recently treated with antibiotics for a urinary infection which improved without complica-

Case 8

Diagnosing Small Renal Calculi using Low Dose Dual Energy CT at 0.8 mSvBy Hilton Muniz Leao Filho, MD, Caroline Bastida de Paula, BM, Vinicius Zim Henrique, PM

Department of Radiology of Hospital do Coração, Brazil



Scan area Abdomen / Pelvis

Scan length 422 mm


Scan time 5 s


Tube current 35 / 14 eff. mAs


CTDIvol 1.21 mGy

DLP 54 mGy cm



Pitch 0.6

Slice collimation 128 × 0.6 mm

Slice width 1 mm

Reconstruction increment 0.7 mm

Reconstruction kernel D30f

DiagnosisThe entire abdominal region was scanned and two small renal calculi, measuring up to 3 mm, were depicted on the left side. The calculi were characterized as non-uric acid exhibit-ing densities of up to 515 HU. Neither hydronephrosis nor ureteral calculi were shown. The evaluation of the rest of the region was unremarkable.

CommentsExcellent detection and characteriza-tion of urinary calculi are achievable using a very low dose protocol. The homogeneous blue color in the bones indicates that the algorithm works very well even using such a low dose. However, it should also be noted that the patient’s body weight and habitus are important factors to consider when choosing the right dose. This patient was young and had a BMI of 19 kg/m2. Such small calculi could be wrongly colored or even remain undetectable if a similar low dose were applied to a heavier patient, mainly due to increased image noise.

Clinical Results Urology


1B1A

Oblique MPR images show two tiny renal calculi on the left. One is about 3 mm in diameter (arrows), and the other one is even smaller (dashed arrows).

1

2B2A

DE images reveal two renal calculi on the left. The bigger one (arrows) exhibits densities of up to 515 HU, and both were classified as non-uric acid.

2

Urology Clinical Results


contain no molecules with a greater atomic number than oxygen. This explains why, like uric acid, stents are distinguishable from non-uric acid stones.[2, 3] If a different type of stent is used, the differentiation from uri-nary calculi will depend on whether its molecular composition is signifi-cantly different to that of common calculi.

History

A 36-year-old male patient, with two indwelling ureteric stents (Double J stents) placed in both ureters, was admitted to the hospital. Prior to the removal of the stents, a CT examina-tion was ordered to evaluate if the prior stones had been all cleared and if any new stones had formed.

DiagnosisA few kidney stones in each kidney were detected. Two of the stones were clinically significant. Both were calcium-based stones measuring 5 mm in diameter. One of these stones was in the lower pole of the left kidney and the other in the upper pole of the right kidney, located within the curve of the ureteric stent (Fig. 1). On conventional CT images, the renal calculus is isodense with the ureteric stent and nearly impossible to differentiate if they are touching. The Dual Energy scan allowed to this stone to be resolved from the adja-cent ureteric stent (Figs. 2–4).

CommentsThe proposed method shows great promise for distinguishing non-uric acid stones from ureteric stents. The method is expected to be valid for at least 90% of nephrolithiasis cases based on the current type of urinary stents.[1] Current Double J stents are generally made of polyurethane. Thus, like uric acid (C5H4N4O3), they

Case 9

Differentiating Stent from Stone: A New Approach using Dual Energy CTBy Boris Waldman BSc, LLB, Eddy Rizk BRadSci, Joseph Sanki MBBS

Superscan Radiology, New South Wales, Australia

References[1] Moe OW. Kidney stones: pathophysiology

and medical management. Lancet;367:333-44.

[2] Manglaviti G, Tresoldi S, Guerrer CS, et al. In vivo evaluation of the chemical compo-sition of urinary stones using dual-energy CT. AJR American Journal of Roentgenology;197:W76-83.

[3] Stolzmann P, Kozomara M, Chuck N, et al. In vivo identification of uric acid stones with dual-energy CT: diagnostic perfor-mance evaluation in patients. Abdominal Imaging;35:629-35



Scan area Abdomen / Pelvis

Scan length 439.5 mm


Scan time 13.5 s


Tube current 268 / 204 eff. mAs


CTDIvol 8.25 mGy

DLP 394 mGy cm


Rotation time 0.5 s

Pitch 0.85


Slice width 0.75 mm

Reconstruction increment 0.5 mm

Reconstruction kernel Q30f

Clinical Results Urology


Coronal MPR images show one stone in the lower pole of the left kidney (arrow), and the other one in the upper pole of the right kidney which is difficult to distinguish from the stent.

1 VRT image generated from the DE scan shows the stone (in blue) located within the curve of the right ureteric stent.

2

Coronal MPR images demonstrate that the stone located within the curve of the right ureteric stent is much easier to see on the DE image (Fig. 3B, in blue).

3 Axial images show that the stone located within the curve of the right ureteric stent is much easier to see on the DE image (Fig. 4B, in blue).

4

1A

3A

1B

3B 4A

4B

2


DiagnosisThe CT images demonstrated a tracheal stenosis between the innom-inate artery and the oesophagus (Figs. 1 and 2). Both lungs showed no abnormalities and the course of the thoracic aorta and its branches were normal (Fig. 3). An aortopexy was considered for further treatment.

CommentsDue to the critical situation of the baby, sedation was not an option. Therefore, the scanning was per-formed with free-breathing using

History A 10-week-old baby girl with con-genital tracheomalacia was admitted to the hospital due to acute obstruc-tive bronchitis. She was suffocating and unconscious with notable lip cyanosis. After emergency treatment, a bronchoscopy was performed reveal-ing a long segmental tracheomalacia. During the examination, the trachea completely collapsed. A thoracic CT was ordered for pre-operative planning.

Case 10

Diagnosing Tracheal Stenosis in a 10-week-old Baby without Sedation By Prof. Oliver Mohrs, MD, Barbara Brecher, MD, Andrej Jörg,* Christoph Lauff*

Radiologie Darmstadt at Alice-Hospital, Darmstadt, Germany *Siemens Germany, Business Management CT



Scan area Thorax Rotation time 0.28 s

Scan length 104 mm Pitch 3

Scan direction Cranio-caudal Slice collimation 128 x 0.6 mm

Scan time 0.26 s Slice width 0.6 mm

Tube voltage 80 kV Reconstruction increment 0.3 mm

Tube current 40 mAs Reconstruction kernel B31f

Dose modulation CARE Dose4D Contrast

CTDIvol 0.84 mGy Volume 7 mL

DLP 11 mGy cm Flow Rate 1 mL/s

Effective dose 0.99 mSv Start delay Bolus tracking

the Flash mode. The required scan time was only 0.26 s and the image quality was fully diagnostic. In order to lower the patient dose, 80 kV was selected for the scanning which resulted in a higher contrast to noise ratio and a dose of only 0.99 mSv.

The Flash mode provides very short scan time and therefore enables CT examination for babies without seda-tion. Combined with lower kV settings, sufficient diagnostic information is obtained even with a very low dose.

Clinical Results Pediatrics


The posterior view of the VRT images demonstrates the tracheal stenosis (arrows) and the innominate artery running across the front of the trachea.

1

1A 1B

A VRT image reveals the normal course of the thoracic aorta and its branches.

3

3

An axial image shows the tracheal stenosis (arrow) between the innominate artery and the oesophagus.

2

2

Pediatrics Clinical Results


In parts I and II of this series, the key image parameters in Computed Tomography (CT) were discussed for low and high contrast resolution. In this third part, the most common artifacts in CT images, their origin, and possible ways to correct them are in focus.

The term “artifact” originally derived from the Latin phrase “arte factum” which translates as “(something) made with skill”. In radiology, “artifact” refers to unwanted structures in the image that are artificially created, are not normally present, and therefore do

not represent the real anatomy or pathology of the patient.

Artifacts in CT are usually based on imperfections in the data or a mis-interpretation of the measured pro-jection data due to various physical phenomena. As CT images are still generally derived by means of filtered back-projection,[1] artifacts not only occur at the originating location as common in conventional radiography, but may also affect the entire image. For example, a thin metallic wire causes streak artifacts emanating from its origin, but also disturbs a larger part of the surrounding area.

Beam-hardening artifacts

The most prominent beam-hardening artifact is known as the “Hounsfield bar”, a dark band between the petrous bones in the base of the skull obliterat-ing the mid portion of the brain stem (Fig.1A). During a CT scan, the tube emits a polychromatic X-ray spectrum that contains photons of differing energies.

Attenuation of X-rays depends on the energy, but this attenuation decreases with higher photon energy. Therefore, the spectral consistency of X-rays changes as they pass through an object:

Science

Image Quality in Computed TomographyPart III: Artifacts

By Stefan Ulzheimer, PhD and Rainer Raupach, PhD


Beam-hardening artifacts: Hounsfield bar, the dark band between the petrous bones in the base of the skull obliterating the mid portion of the brain stem (Fig. 1A). Fig. 1B shows the same slice as Fig. 1A: Improvement with beam-hardening correction.

1

1A 1B


Radiation behind the object contains a higher proportion of high-energy photons than the primary beam, but fewer low-energy photons. The signals measured at the detector, however, represent an averaged attenuation over all energies resulting in averaged data. As a result, reconstructed images show dark areas or streaks, for instance between dense bones.

The strength of this “beam-hardening effect” depends significantly on the atomic composite, the size of the object, and the voltage used. Heavy atoms such as calcium in bones cause a more distinct effect than soft tissue. A lower voltage with a lower peak energy in the X-ray photons intensifies the artifacts. It follows then that dense bones, very concentrated iodine contrast media, or implanted metals may cause signifi-cant beam-hardening artifacts.

Correction of this effect for soft tissue is routinely performed during data processing to provide a homogeneous soft tissue level over the entire object. However, simultaneous beam-harden-ing correction for a combination of soft tissue, bone, etc. requires more sophis-ticated algorithms, such as iterative reconstruction approaches.

Siemens CT systems provide dedicated reconstruction algorithms enabling almost complete removal of artifacts in brain scans. On top of that dedicated algorithms are also available for cardiac

imaging that consider the two com-ponents, soft tissue and bone.[2]

Partial volume artifacts

Partial volume artifacts occur when the edge of a high contrast structure, for example bone or metal, partly overshadows a particular channel when projecting onto the detector. In this case, the signal measured is the cumulated intensity of the rays passing exclusively through the object and the environmental tissue. This applies to in-plane projections as well as to the z-direction. The data acquired is then incorrect, because the signal attenuation is measured, but CT images are reconstructed by means of a filtered back-projection of attenuation integrals.[1] Here, artifacts are typically streak-shaped and may look very similar to beam-hardening artifacts.

As detector channels in multislice computed tomography (MSCT) are small in width, sampling artifacts occur only at the edges of objects with very high attenuation coefficients, such as metallic objects or small dense calcifications. Thinner collimation reduces the level of partial volume artifacts, because contours are sam-pled more precisely. All Siemens MSCT systems have scan modes with sub-millimeter collimation that should be used where high contrast structures are present.

Artifacts in a thorax scan from breathing and movement of the heart (Fig. 2A).Improvement with a motion artifact correction algorithm (Fig. 2B).

2

Spiral or “windmill” artifacts without z-Sharp (Fig. 3A).No windmill artifacts with z-Sharp (Fig. 3B).

3

2A

3A

3B

2B

Science


Science

Motion artifacts

CT images are reconstructed in a par-ticular segment of projections. Move-ment of an object or patient during this time leads to inconsistent data. Artifacts typically occur as streaks, blurred or double contours (Fig. 2A). Protocols for critical examinations may include special motion correction algorithms to suppress such artifacts (Fig. 2B).

Generally, a fast gantry rotation speed is recommended to minimize motion artifacts. The SOMATOM Definition Flash and Edge offer rotation times down to 0.28 seconds per 360 degrees, fast enough to freeze physiological processes. Dedicated cardiac recon-struction algorithms can be used to display sub-millimeter structures near to the heart, for example coronary arteries. These use information from an ECG taken in parallel to determine optimized temporal windows and require only 180 degrees of data to reconstruct a CT image with improved temporal resolution. Temporal resolu-tion can be further improved with Dual Source technology on the SOMATOM Definition Flash. Even uncooperative patients and children can be scanned without the appearance of motion artifacts using Dual Source. Siemens’ latest generation of Dual Source CT –

the SOMATOM Force – increases the rotation speed even to 0.25 seconds per rotation, allowing a large number of patients to be scanned without breathhold.

Spiral artifacts (windmill artifacts)

CT scanners acquire raw data from finite detector channels. All spiral reconstruction algorithms require an interpolation in the z-direction of this data to axially aligned projections. This induces errors in cases of high contrast objects, such as bones or metals, compared with the idealized situation of an arbitrarily fine grid of sampled data points. Resulting arti-facts appear as windmill-like structures near to their sources (Fig. 3A) and seem to rotate around the center when scrolling through the stack of axial images.

Spiral artifacts can be reduced effec-tively by improving the sampling pattern in the z-direction. Siemens’ proprietary z-Sharp technology with double z-sampling [3] is an advanced approach that can completely over-come this well-known issue with MSCT systems (Fig. 3B). Other vendors need to offer fixed low pitch protocols to improve sampling; however, Siemens z-Sharp allows the pitch to be adjusted over a wide range to continuously

Artifacts caused by metal implants (Fig. 4A). Dual Energy based metal artifact reduction (MAR) in 140 keV monoenergetic images (Fig. 4B). VRT of the metal prosthesis with MAR (Fig. 4C).

4

adapt scanning speed to the clinical task. This technology is therefore superior to other approaches to reduc-ing spiral artifacts through scan and reconstruction parameters. z-Sharp is provided for all Siemens CT systems using the renowned STRATON tube, as well with the latest tube generation, the VECTRON tube introduced with SOMATOM Force.

Cone artifacts

Cone artifacts arise due to an approxi-mation of the measured slices of MSCT systems to truly parallel planes. If the detector width in the z-direction increases, then deviations from this simplified description will also increase resulting in characteristic artifacts. Given that the misfit extends away from the center of rotation, cone artifacts are strongest typically at the periphery, for example near the ribs. Siemens MSCT scanners provide effective cone correction or cone beam reconstruc-tion, when required, depending on the number of detector rows.

Nevertheless, excessive increase in detector coverage as seen with several recent product introductions in the industry, comes along with a signifi-cant increase of these cone and also scatter artifacts. At such an extend, the disadvantages outweigh the clinical benefits of covering large volumes,

4A 4B 4C


especially as the volume coverage can be achieved more effectively with fast acquisition speeds.

Metal artifacts

Metal artifacts are a combination of almost all of the effects described above. The particular effect that may occur depends on the alloy, shape, size, and position. Generally, the transition from tissue to metal is very abrupt compared with the size of the detector channels. So partial volume effects or sampling errors contribute to metal-induced artifacts, which appear as thin streaks emanating from the edges.

As the size of the metallic object increases, so does the attenuation of the X-rays. Beam hardening becomes relevant. Moreover, the absolute signal measured in certain detector elements behind the implant becomes so low that the reading is no longer reliable due to the high level of noise. Both effects may completely destroy the image con-tent for rays passing through a large amount of metal. Using a higher voltage reduces beam hardening as well as a lack of detector signal due to smaller attenuation at higher photon energies. Selecting higher mAs, on the other hand, does not improve the situation significantly but will increase radiation

dose. Intelligent automatic exposure controls such as Siemens CARE Dose4D exclude metallic objects when calcu-lating optimal mAs settings, because no benefit is observed with regard to image quality compared with the higher dose. Dual Energy scanning – which is available on the SOMATOM Force, SOMATOM Definition Flash, the SOMATOM Definition Edge, all SOMATOM Definition AS systems, and now also for SOMATOM Perspective scanner family – can also be used to reduce metal artifacts efficiently by calculating monoenergetic images – another form of advanced beam-hardening correction (Fig. 4A/B). Fur-thermore, all Siemens CT scanners apply advanced filters to the raw data to reduce disturbing noise structures.

Objects outside the field of measurement

The relation between CT raw data and reconstructed images causes arti-facts if objects are inside the gantry, but exceed the field of measurement. Patients larger than the maximal scan-ning field or arms lateral to the body likewise produce artificial hyperdense edges (Fig. 5A) if not accounted for in the reconstruction. The latest Siemens scanners automatically apply advanced

Patient exceeding the field of measurement without correction (Fig. 5A). Same slice as in Fig. 5A reconstructed with HD FoV reconstruction (Fig. 5B).

5

extrapolation-type algorithms (HD FoV) in order to reduce those artifacts con-siderably (Fig. 5B). Moreover, they offer special reconstruction techniques to display objects located outside the field of measurement with high accu-racy. This is especially important in radiation therapy planning where treat-ment plans are based on the correct measurement of CT numbers and parts of the patient are frequently located outside the field of measure-ment due to fixation devices. There are diverse origins of artifacts in CT imaging. Solutions need to be equally diverse to intelligently deliver diag-nostic results.

5A 5B

References[1] Kalender WA: Computed Tomography,

Publicis MCD: 22ff (2000)[2] Herman GT, Trivedi SS. A Comparative

Study of Two Postreconstruction Beam Hardening Correction Methods, IEEE Transactions on Medical Imaging. 1983 Sep; Vol MI-2; No 3: 128-135

[3] Flohr T, Stierstorfer K, Raupach R, Ulzheimer S, Bruder H. Performance evaluation of a 64-slice CT system with z-flying focal spot. Rofo. 2004 Dec;176(12):1803-10.

Science


When refining innovative tools for dose management it is critical to achieve the highest technical perfor-mance to meet the needs of both patients and medical staff. Further-more – influenced by European Com-mission research on the subject – most European countries have now started to regulate the dissemination of good ALARA (As Low As Reason-ably Achievable) practice in medical imaging. So Siemens scored a bull’s eye when it launched CARE Analytics. Being a free of charge application

embedded in the comprehensive Dose Management Program “DoseMAP”, it perfectly ties into the overall “Com-bined Applications to Reduce Exposure” (CARE) philosophy of Siemens.

“I am responsible for radiation hygiene at the Albert Schweitzer Hospital,” explains Jeroen Bosman, medical physicist. “The specific technical regu-lations brought out by our govern-ment cover the safe use of ionizing radiation in all hospitals. They are part of a larger family of radiation protec-tion laws surrounding the use, con-

trol, and equipment producing ioniz-ing radiation, and thus affect most of our scanners and technical equipment. Our hospital must keep to these regu-lations to optimize radiation doses, meaning lowering the dose as much as possible, and also to perform quality control on patient doses.”

Simple and efficient

The measurement and calculation of radiation dose is important for efficient dose management, not only in CT but also for all areas where X-ray exposure

Science

Medical physicists carry a significant responsibility for their patients. Facilitating and establishing a safety culture in a medical environment is therefore one of their main priorities. The Albert Schweitzer Hospital in Dordrecht, the Netherlands, uses Siemens CARE Analytics on a daily basis to keep a check on safety and radiation doses for the radiology and cardiology department equipment.

Radiation Hygiene – Transparent and Easy

“Thanks to the free CARE Analytics tool, we are now able to simplify the rather complex handling of data measure-ment and analysis.”

Jeroen Bosman, Albert Schweitzer Ziekenhuis, Dordrecht, the Netherlands

By Erika Claessens


is used. “Thanks to the free CARE Ana-lytics tool provided by Siemens, my staff and I are now able to simplify the rather complex handling of data mea-surement and analysis,” says Bosman. “Our hospital handles approximately twenty thousand CT scans a year. Before 2012, we had to derive the exact infor-mation from a massive database by asking our staff to manually fill in huge amounts of numbers on paper questionnaires.”

“Those days are over,” Bosman points out, smiling. “Work is now simplified to a huge extent. Moreover, the infor-mation is optimized, filtered by indi-vidually chosen parameters and all the numbers are brought together in simplified colored graphics. Seeing the affect of adjusting a scan protocol doesn’t take a long time anymore.”

Increased transparency

“CARE Analytics was very easy to install on our computers. Our hospital scan-ning equipment contains comprehen-sive data for each irradiation event, the accumulated dose in CT, and informa-tion about the context of the exposure. Until now, this data was only archived in dose structured reports and not pro-cessed any further. The data is now sent to the software tool on our desk-top, where it is stored and processed. With CARE Analytics, we can evaluate and analyze the information in a stan-

dard file format, such as Microsoft Excel for example. This helps us when it comes to optimizing scan protocols and working to reduce dosages. I can also easily provide data information on received patient doses for different systems over a series of examinations to the government inspection officer or other third parties. In the future, dose reporting between multiple hos-pitals could also be made possible. The increased transparency lets us improve our working practices and be more sparing with the doses given than in the past.”

Exploring trends

“In terms of gaining time, installing CARE Analytics was an eye-opener. But my interest is more in using the data gathered to detect unusual situations and trends. Before, it was impossible to clearly disentangle such deviant information. With this software tool, I can zoom in and have a closer look at the information. I can explore it widely and do significant research to work out exactly what happened. This can lead to a protocol adaptation or a new way of working with the CT equipment. Or it could reveal a tech-nical problem we were formerly not aware of. I can adjust scan protocols, choosing from about ten different parameters for scan protocols, with a primary goal of lowering the dose

without compromising image quality. This would never have been possible before when processing the data and adjusting the scanning protocols by hand,” he says. “My work has become more interesting now, as the soft-ware tool offers so many possibilities and opportunities to analyze the numbers.”

Protecting patients and medical staff from unnecessary radiation is a major concern. Today, thanks to advanced technologies and applications, out-comes for diagnosis and intervention can be optimized at the same time as reducing radiation.

CARE Analytics offers many possibilities and opportunities to Jeroen Bosman and his team for efficient dose management.

The Albert Schweitzer Hospital in Dordrecht, the Netherlands, uses Siemens CARE Analytics soft-ware on a daily basis to keep a check on safety and radiation doses for their radiology and cardiology department equipment.

Science

Further Information

www.siemens.com/care-right

Erika Claessens has contributed as a journalist and editor to numerous print and online publications in both Belgium and the Netherlands. Her principal topics are entre-preneurial innovation and technology. She works from Antwerp, Belgium.



introduced into clinical practice, the impact on image quality and radiation dose reduction was studied using a quality image phantom (Catphan 500). Several acquisitions were performed at different kV settings (from 80 to 140 kV), different mAs (from 50 to 350 mAs) and at two pitches (0.8 and 1.2). After each CT scan acquisition, the CTDIvol was recorded and the raw data was reconstructed with filtered back projection and SAFIRE at a strength of 5 for three reconstruction thicknesses and two different filters (B30/I30 and B70/I70). In total, 2,016 parameter combinations were evalu-ated. syngo.via was used to measure the signal and noise for a standard-ized ROI with five different inserts (air, low density polyethylene, water, acrylic, teflon) and an in-plane spatial resolution (MTF 10%).

Calculations of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) showed significantly decreased noise with increasing levels of SAFIRE, without any change in the signal and modular transfer function (MTF). It could be concluded that increasing SAFIRE levels improve the image qual-ity indices with identical radiation doses (qualitative advantage). There-fore, if parameters are optimized during acquisition to reduce patient dose, SAFIRE can compensate for the increase in noise and deliver the same high quality image as before (quanti-tative advantage).

over 28,000 CT scans and traditional X-rays were performed by 22 technol-ogists and 13 radiologists.

As part of a drive to improve workflow efficiency and clinical practice, Joel Greffier, medical physicist, and Jean-Paul Beregi, MD, head of radiology at CHU Carémeau – conducted a series of studies. Important parameters for improvement were patient manage-ment, image availability and quality, radiation dose, and reproducibility. The main objective was to investigate new dose reduction technologies in routine CT scanning.

Before Siemens Sinogram Affirmed Iterative Reconstruction (SAFIRE) was

The CHU Carémeau is part of the university of Nîmes in the south of France. It facilitates 1,200 beds and the hospital provides healthcare to 450,000 inhabitants. Emergency care is available 24 hours a day, 7 days a week. With an average of 63,000 emergency admissions per year, scans are required day and night for all indications – bones, brain, abdomen or cardiovascular – regardless of how acute the case. In 2011, a new SOMATOM® Definition AS+ CT scanner for use mainly in emergency cases and for in-patients replaced the pre-vious device. A second CT scanner (acquired in 2009) was upgraded to the same level as the first one. In 2012,

1

Radiation dose reduction in daily practice showed no adverse impact on image quality. Radiation dose reduced by 15% and then 30% in reference mAs (compared with previous practice) was applied in all thoracic and abdomino-pelvic protocols.

1

The “Centre Hospitalier Universitaire Carémeau” (CHU Carémeau) is a large and busy hospital in the south of France. Maintaining workflow efficiency while keeping investigations and diagnosis safe is a major challenge in the current circumstances. Results from a series of studies conducted on-site have been successfully integrated into daily practice. This has enabled smoother workflows and a clear decrease in radiation dose.

Radiation Protection Scientifically Proven for Routine Practice

By Jean-Paul Beregi, MD, PhD, and Joel Greffier

Department of Radiology at Centre Hospitalier Universitaire Carémeau, France

Science


Science

Table 1: Radiation Dose used in Nîmes vs. Recommendations by French authorities

CTDIvol (mGy)

Exam Frenchrecommendations

Nîmes2012

Nîmes2013

Nîmes2012 vs. 2013

French recommendationsvs. Nîmes 2013

Chest 15mGy 4.2mGy 2.5mGy – 40.5% – 83.3%

Abdominal 17mGy 7.5mGy 5.1mGy – 32.0% – 70.0%

Lumbar Spine 45mGy 16.2mGy 8.8mGy – 45.7% – 80.4%

Head 65mGy 48.8mGy 36.3mGy – 25.6% – 44.2%

The same methodology was then applied to an anthropomorphic phan-tom (Rando) and results were com-pared to those obtained with the Catphan 500. In practice, all CT scans were executed with CARE Dose4D activated and with CARE kV activated or semi-activated (depending on local-ization and exam type) to reduce radi-ation dose. Furthermore, a systematic reduction in mAs was applied by the percentage reductions in the reference. The kV was kept constant to avoid sig-nal variation and so as not to change the pitch since there was no effect on radiation dose. Both kVp and pitch were adapted to the location and type of exam. With a decrease in the refer-ence mAs, a parallel reduction in the effective mAs during acquisition was observed. This reduction in effective mAs was linear to radiation dose reduction.

This decrease in mAs was introduced into daily practice gradually over two months to allow all radiologists to adapt and also to be entirely sure that there was no impact on image quality for routine diagnosis. A 15% and then 30% reduction in reference mAs

patients whose weight is not known. There is, however, some space for improvement. The team is now work-ing to optimize the protocol to fit the specific needs of the physician request-ing the exam. For example, they have a new protocol for urinary stones where irradiation can be decreased (<70%). Abdominal structures present more noise, but it is possible to see urinary calculi without any change in accuracy (Fig. 2).

Our results show that medical person-nel and patients at the CHU Carémeau radiology department benefit from using SAFIRE in clinical routine – which we were able to confirm through studies. Offering the clinical staff the chance to become familiar with the functionalities of SAFIRE increased acceptance and convinced them firmly of the advantages of using SAFIRE in daily practice.

(compared with previous practice) was applied in all thoracic and abdomino-pelvic protocols. Iterative reconstructions with two levels of SAFIRE (strength 3 and strength 4) were offered to radiologists (strength 2 was the initial choice before dose reduction). During this period, we observed that routine workflow remained unchanged. Radiologists were surprised by the change in the image, but there were no cases of mis- interpretation or difficulties in evalu-ating nodules or infiltrations. Radiolo-gists were given some training to help them to understand the benefits of the dose reduction technologies and to convince them of the choice (Fig. 1).

In routine practice, radiation dose reduction has now been introduced for all scan protocols and SAFIRE (mainly level 3 or 4 according to the protocol) is used. The choice was to have the lowest dose for all patients, especially for pregnant women where radiologists do not need a specific protocol (Tab. 1). For the moment, there is no weight-adapted kVp proto-col to standardize acquisitions or for

In an optimized protocol for urinary stones, irradiation was decreased by more than 70 percent (Fig. 2B) compared with previous protocols (Fig. 2A). Urinary calculi can be detected without any change in accuracy.

2

2A 2B

The statements by Siemens customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical” hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.


In syngo.via VA20 syngo.CT Vascular Analysis and MM Reading, the bone removal function can be used to create an individual isolation of high intensity structures, such as bones and contrast-enhanced vessels. This function allows, for example, to remove only the joint socket for a view of a fractured joint.

Define structures

When using the Bone & Vessel Isola-tion mode for the first time, the bone removal edit mode is automatically

started. In the edit mode, the func-tions provided to define an individual removal mask can be used. It makes manual marking of individual bone and vessel structures possible in order to apply a user-specific bone mask for each dataset. Unlike the other bone removal options, this mode starts with an unmarked volume and allows the user to define structures. After finishing the removal mask, the edit-ing mode has to be deactivated. The editing results are retained in the removal mask. By clicking the “Bone

& Vessel Isoltion” icon, the removal mask can be displayed or hidden. To further modify the removal mask, the bone removal mask has to be started again.

Optimized view

Based on the structures that are marked as bones in the bone mask, bone structures can be highlighted in MPR and VRT images. The highlighting functions can be used to optimize the bone removal masks. In the editing mini toolbar, click the “Hide marked structures” icon or “Show marked structures” icon.

In the VRT segment, an adjustable semi-transparent view of the bones can be displayed. This view is based on the structures that are marked or unmarked as bone in the bone removal mask. From the upper left corner of the VRT segment, choose “Bone Opacity”. In the bone opacity mini toolbar at the bottom of the segment, the marked /unmarked slider can be dragged to the left or to the right to change the opacity level of the structures.

1

2

“Bone Opacity” from the upper left corner of the VRT segment allows to view the marked and unmarked structures.

1

In the VRT segment all identified bone structures are hidden. Clicking on a structure (displayed in transparent blue) allows to add (blue plus sign) or remove (red minus sign) it from the removal mask. In the editing mini toolbar, marked structures can be shown or hidden.

2

Customer Excellence

Tips & Tricks: Easy Bone and Vessel Isolation By Patricia Jacob, Computed Tomography, Siemens Healthcare, Forchheim, Germany


Clinical Workshops 2014As a cooperation partner of many renowned hospitals, Siemens Healthcare offers continuing CT training programs. In a wide range of workshops clinical experts share latest experiences and options in clinical CT imaging.

Workshop Title / Special Interest

Date Location Course Language

Course Director/Organizer Link

SCCT CTA Academy 2014 January 11 – 12, 2014

Hawaii, USA

English

Siemens Healthcare Prof. Stephan Achenbach, MD Suhny Abbara, MD

www.scct.org/training/cta/

Clinical Workshop on Dual Energy

February 14 – 15, 2014

Forchheim, Germany

EnglishSiemens Healthcare Prof. Thorsten Johnson, MD

www.siemens.com/SOMATOMEducate

Workshop for PhysicistsMarch 18 –19, 2014

Forchheim, Germany

English Siemens Healthcarewww.siemens.com/SOMATOMEducate

Coronary CTA Interpretation Workshop

March 27 – 28, 2014

Erlangen, Germany

EnglishSiemens Healthcare Prof. Stephan Achenbach, MD


Hands-on at the ESGAR Workshop/Colonography

April 24 – 26, 2014

Oslo, Norway

EnglishESGAR Anders Drolsum, MD

www.esgar.org

Advanced Cardiovascular CT April 29 – May 2, 2014

London, UK

English

Imperial College London: Ed Nicol, MD; Simon Padley, MD and Sujal Desai, MD

www.imperial.ac.uk

Hands-on at the ESGAR Congress/Colonography

June 18 – 21, 2014

Salzburg, Austria

EnglishESGAR Prof. Gerhard Mostbeck, MD

www.esgar.org

Oncology Imaging Course 2014/Oncology

June 26 – 28, 2014

Dubrovnik, Croatia

EnglishOICProf. Maximilian Reiser, MD

www.oncoic.org

Workshop for PhysicistsSeptember 23 – 24, 2014

Forchheim, Germany

English Siemens Healthcarewww.siemens.com/SOMATOMEducate

Hands-on at the ESGAR Workshop/Colonography

October 8 – 10, 2014

Leeds, UK

EnglishESGARDamian Tolan, MD

www.esgar.org

Coronary CTA Interpretation Workshop

November 6 – 7, 2014

Erlangen, Germany

EnglishSiemens Healthcare Prof. Stephan Achenbach, MD


In addition, you can always find the latest CT courses offered by Siemens Healthcare at www.siemens.com/SOMATOMEducate

Customer Excellence


Upcoming Events & Congresses 2013/2014

Short Description Date Location Title Contact

Radiological Society of North AmericaDecember 01 – 06, 2013

Chicago, USA RSNA www.rsna.org

Internationales Symposium Mehrschicht CT

January 22 – 25, 2014

Garmisch- Partenkirchen, Germany

Mehrschicht CT

www.ct2014.org

Arab HealthJanuary 27 – 30, 2014

Dubai, UAE Arab Health www.arabhealthonline.com

European Society of RadiologyMarch 06 – 10, 2014

Vienna, Austria ECR www.myesr.org

European Society for Radiotherapy & Oncology

April 04 – 08, 2014

Vienna, Austria ESTRO www.estro.org

Cardiac Magnetic Resonance Imaging & Computed Tomography

April 11 – 13, 2014

Cannes, FranceCardiac MRI & CT

http://cannes2014.medconvent.at

European Conference on Interventional Oncology

April 23 – 26, 2014

Berlin, Germany ECIO www.ecio.org

European Stroke ConferenceMay 06 – 09, 2014

Nice, France esc www.eurostroke.eu

American Society of Clinical OncologyMay 30 – June 03, 2014

Chicago, USA ASCO www.am.asco.org

European Society of Pediatric RadiologyJune 02 – 06, 2014

Amsterdam, The Netherlands

ESPR www.espr.org

International Society for Computed Tomography

June 09 – 12, 2014

San Francisco, USA ISCT www.isct.org

European Society of Thoracic ImagingJune 12 – 14, 2014

Amsterdam, The Netherlands

ESTI www.myesti.org

European Society of Gastrointestinal and Abdominal Radiology

June 18 – 21, 2014

Salzburg, Austria ESGAR www.esgar.org

Society of Cardiovascular Computed Tomography

July 10 – 13, 2014

San Diego, USA SCCT www.scct.org

European Society of CardiologyAugust 30 – September 02, 2014

Barcelona, Spain ESC www.escardio.org

American Society for Radiation OncologySeptember 14 – 17, 2014

San Francisco, USA ASTRO www.astro.org

European Society for Medical OncologySeptember 26 – 30, 2014

Madrid, Spain ESMO www.esmo.org

Radiological Society of North AmericaNovember 30 – December 05, 2014

Chicago, USA RSNA www.rsna.org

Customer Excellence


A bi-annual conference for CT practitio-ners, the 11th SOMATOM World Summit took place for the first time in the United States in Orlando, Florida. Under the inspiring theme “Connecting Knowl-edge”, this year’s conference offered another unique opportunity to connect medical staff from around the world to share their experience and understand-ing of the latest developments in CT.

State-of-the art technology was the focus of the conference with a special emphasis on dose management and patient care in optimizing the clinical workflow in daily routine. An impres-sive range of experts gave lectures covering the following clinical themes:

Right Dose CT imaging Acute care New horizons in Dual Energy Synergies in CT for better patient care Vascular Cardiology Neurology Pediatrics Oncology Therapy

Established products such as Dual Energy, SAFIRE, and FAST CARE (including CARE kV, CARE Child) and the new Stellar detector technology were analyzed from a clinical per-spective. Each subject was illustrated with practical examples from routine hospital settings or during clinical trials. One example was the use of the Stellar detector in combination with CARE Dose4D to reduce radia-tion dose while providing excellent image quality.

The most up-to-date information about technical innovation in CT is shared in clinical conferences, workshops, and supporting material. Siemens Healthcare offers an established and comprehensive clinical platform with a wide range of educational programs. They include informative and inter-esting publications, a series of “How to” flyers with useful expert advice, webinars, training programs (fellow-ships, workshops, and hands-on tutorials) to extend and consolidate knowledge.

Connecting Knowledge in Orlando, Florida: Listening to the latest innovation in CT

Siemens’ educational platform offers additional valuable information on ways to improve clinical skills and usage of Siemens CT systems to their full potential. The new DVD of the SOMATOM World Summit featuring recordings of the presentations is now ready for delivery. This e-learning method is an excellent way to learn about state-of-the-art CT at one’s own pace and at a time and place conve-nient. True to the motto “Connecting Knowledge”, a free copy can be ordered through the following link:

Further Information


Customer Excellence

Free DVD of the 11th SOMATOM World Summit in OrlandoBy Katrin Seidel, Computed Tomography, Siemens Healthcare, Forchheim, Germany


STAR is an acronym for Specialized Training in Advances in Radiology. It is an international educational program for practicing radiologists. In 2013, twenty years of success in driving and sharing knowledge with STAR were celebrated. STAR events include a reg-ular forum to share opinions on and experiences of the latest developments in radiology together with an eminent faculty of independent experts. The two-day format has proved popular over the years and includes 13 lectures (45 min.) complemented by five one-hour workshops for detailed case dis-cussions. Pathological conditions in all body organs and all modalities are covered. An excellent advisory board of 21 leading radiologists from all over the world supports the STAR program with valued expertise. STAR is jointly sponsored by Siemens and Bayer Healthcare and is run as a non-com-mercial educational initiative.

Country-specific programs

An important feature of STAR is cooper-ation with national radiology societies. They are involved in defining topics appropriate to the needs of the respec-tive countries – be it the healthcare system, access to radiology equipment or training on a specific subject. Rep-resentatives of the societies also play an active role as program chairs. Atten-dance at STAR meetings varies greatly with countries sending between

STAR event in New Delhi, India, 2012

Further Information

www.star-program.com

Customer Excellence

Enthusiastic feedback

The most convincing evidence of the STAR programʼs success is the enthusi-asm of its participants. Feedback is given after each event to assess its educa-tional value, the quality of the speakers, and the interest of the participants in attending future STAR meetings. Visiting radiologists appreciate “the high quality of the conference”, and the “practical knowledge that you can never find in the literature”, and the chance “to learn from the best of the best international faculty”. STAR meetings are in constant demand and are often repeated in coun-tries where previous programs have been held.

To learn more about STAR please visit the following website.

100–500 participants. Programs are held at locations around the world to facilitate participation and allow for a customized approach according to local needs and reflecting national charac-teristics. To date, 169 STAR events have been held in 36 countries across the globe, attended by almost 27,000 radiologists, and supported by around 200 faculty members. The next STAR events are scheduled for January 2014 in Vietnam and Thailand.

The total numbers of countries, sites, and participants show the continuous expansion of the STAR program over 20 years.

Accumulated number of participants30000

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Twenty Years of STAR – A Successful Educational Program for RadiologistsBy Axel Lorz, Computed Tomography, Siemens Healthcare, Forchheim, Germany


SOMATOM Sessions has grown steadily. For more than 12 years, the printed magazine has delivered the latest news from the world of computed tomography. People’s reading habits, however, are changing radically and the customer magazine adapts, too.

In June 2011, the online equivalent of SOMATOM Sessions was launched. This online version offers all articles available in print as well as exclusive content at www.siemens.com/SOMATOM-Sessions. Readers can com-ment on and forward articles, find arti-cles relating to a topic and interesting links to further information. Addition-ally topics can be sorted and organized by clinical interest. The online platform makes the very latest content – such as reports from trade fairs – available to readers quickly.

In 2012, by multiple requests the SOMATOM Sessions app was developed for Apple and Android to add even

more value. Both website and app offer new multi-media content and opportunities for interaction.

In the app, users can configure their start page according to their interests, bookmark content to read later offline, rate articles and share content easily. Download the app from iTunes or the Google Play Store for free – keyword: “CT Sessions.”

Further Information

www.siemens.com/SOMATOM-Sessions

There is a SOMATOM Sessions for everyone – see which one suits you best.

With a broad base of readers, the Siemens customer magazine for computed tomography now has a range of formats – to suit everyone.

From January 22 – 25, 2014, the 8th International Symposium for Multislice CT will take place in Garmisch-Parten-kirchen, Germany. In keeping with the concept of “Life Long Learning”

emphasis will be placed on practical, hands-on training. Another focus will be the latest scientific developments and technical innovations in the field of computed tomography (CT), that in all probability will strongly affect quality of future clinical practice. Sym-posium events will demonstrate ways in which to combine clinical research and practical application in CT more effectively. Leading experts will guide participants through a high-level pro-gram including clinical lectures and refresher courses. Specific case stud-ies and results from cardiology, acute diagnostics, neurology, ENT, oncology and other fields will be presented and discussed in the round. A new inter-active file-reading session will take place for the first time. In this session,

Further Information

http://www.ct2014.org

From January 22–25, 2014, the 8th Inter- national Symposium for Multislice CT will take place in Garmisch-Partenkirchen, Germany.

leading experts in various medical fields will provide live analysis of cases with opportunities for the audience to take part and work out solutions together.

The symposium is accredited by the Bavarian “Landesärztekammer” so participants will have the option of registering for CME credits. The conference language is German.

2014 Multislice CT Symposium in GarmischBy Monika Demuth, PhD, Computed Tomography, Siemens Healthcare, Forchheim, Germany

Customer Excellence

From Print to App: SOMATOM Sessions for EveryoneBy Sandra Kolb, Computed Tomography, Siemens Healthcare, Forchheim, Germany

Subscription


Siemens Healthcare PublicationsOur publications offer the latest information and background for every healthcare field. From the hospital director to the radiological assistant – here, you can quickly find information relevant to your needs.

Medical Solutions Innovations and trends in healthcare. The magazine is designed especially for members of hospital man-agement, administration personnel, and heads of medical departments.

MAGNETOM Flash Everything from the world of magnetic resonance imaging.

Heartbeat Everything from the world of sustainable cardiovascu-lar care.

AXIOM Innovations Everything from the world of interventional radiology, cardiology, and surgery.

Imaging Life Everything from the world of molecular imaging innovations.

SOMATOM Sessions Online The online version includes additional video features and greater depth to the articles in the printed SOMATOM Sessions magazine. Read online at: www.siemens.com/SOMATOM-Sessions

For current and past issues and to order the magazines, please visit www.siemens.com/healthcare-magazine

© 2013 by Siemens AG, Berlin and Munich, All Rights Reserved

Publisher: Siemens AG, Healthcare Sector Henkestrasse 127, 91052 Erlangen, Germany

Chief Editors: Monika Demuth, PhD; Stefan Ulzheimer, PhD

Clinical Editor: Xiaoyan Chen, MD

Project Management: Miriam Kern; Sandra Kolb

Responsible for Contents: Peter Seitz

Editorial Board: Xiaoyan Chen, MD; Monika Demuth, PhD; Andreas Fischer; Jan Freund; Julia Hölscher; Axel Lorz; Peter Seitz; Stefan Ulzheimer PhD

Authors of this issue: Bastida de Paula, Caroline, Department of Radiology of Hospital do Coração, Brazil

Bauer, Ralf W., MD, Department of Diagnostic and Interventional Radiology, Goethe University, Frankfurt, Germany

Beregi, Jean-Paul, MD, PhD, Department of Radiology at CHU Carémeau, France

Brecher, Barbara, MD, Radiologie Darmstadt at Alice-Hospital, Darmstadt, Germany

Cao, Jian, MD, Department of Radiology, Peking Union Medical College, Beijing, P.R. China

Deconinck, D., MT, Medical Imaging Department, Europa Clinics, Brussels, Belgium

Derauw, O., MT, Medical Imaging Department, Europa Clinics, Brussels, Belgium

Dikraniant, T., MD, Internal Medicine Department-Cardiology, Europa Clinics, Brussels, Belgium

Frellesen, Claudia, MD, Department of Diagnostic and Interventional Radiology, Goethe University, Frankfurt, Germany

Genard, L., MT, Medical Imaging Department, Europa Clinics, Brussels, Belgium

Ghijselings, L., MD, Medical Imaging Department, Europa Clinics, Brussels, Belgium

Graef, Anita, MD, Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Germany

Greffier, Joel, Department of Radiology at CHU Carémeau, France

Hilton Muniz, Leao Filho, MD, Department of Radiology of Hospital do Coração, Brazil

Hofman, Paul AM, MD, Dept. of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands

Zim Henrique, Vinicius, PM, Department of Radiology of Hospital do Coração, Brazil

Irène Dietschi, science and medical writer, Switzerland; Erika Claessens, journalist and editor, Belgium; Philipp Grätzel von Grätz, MD, freelance writer and book author, Germany; Sameh Fahmy, MS, freelance medical and technology reporter, USA; Christian Rayr, freelance journalist, France; Philipp Braune, Kommpagnons, Germany

Peter Aulbach; Arjen Bogaards, PhD; Monika Demuth, PhD; Jochen Dormeier, MD; Ivo Driesser; Heidrun Endt, MD; Jan Freund; Tomoko Fujihara; Florian Hein; Susanne Hölzer, Patricia Jacob; Andrej Jörg; Sandra Kolb; Christoph Lauff; Axel Lorz; Jürgen Merz, PhD; Dominik Panwinkler; Rainer Raupach, PhD; Andreas Rumpp; Katrin Seidel; Philip Stenner, PhD; Stefan Ulzheimer, PhD; Xi Zhao, MD

Photo Credits: Anna Schroll / fotogloria; Wolfram Schroll / fotogloria; Franck Ferville / Agence Vu, Matti Immonen; Miquel Gonzalez / laif, Philipp Braune / Kommpagnons

Production and PrePress: Norbert Moser, Kerstin Putzer, Siemens AG, Healthcare Sector Reinhold Weigert, Typographie und mehr ... Schornbaumstrasse 7, 91052 Erlangen

Proof-reading and translation: Sheila Regan, uni-works.org

Design and Editorial Consulting: Independent Medien-Design, Munich, Germany In cooperation with Primafila AG, Zurich, Switzerland Managing Editor: Mathias Frisch Photo Editor: Julia Berg Layout: Claudia Diem, Mathias Frisch, Pia Hofmann, Heidi Kral, Irina Pascenko All at: Widenmayerstraße 16, 80538 Munich, Germany

The entire editorial staff here at Siemens Healthcare extends their appreciation to all the experts, radiologists, scholars, physicians and technicians, who donated their time and energy – without payment – in order to share their expertise with the readers of SOMATOM Sessions.

SOMATOM Sessions on the Internet: www.siemens.com/SOMATOM-Sessions

Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system.SOMATOM Sessions with a total circulation of 25,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their application as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and discusses their clinical potential.The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher.The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the prac-tice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Solutions to be used for any purpose in that regard.

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary.Partial reproduction in printed form of individual contributions is permitted, pro-vided the customary bibliographical data such as author’s name and title of the contribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article.We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and information are always welcome; they are carefully examined and submitted to the editorial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

Johnson, Thorsten R. C., MD, Institute for Clinical Radiology, Ludwig-Maximilians University Hospital Munich, Germany

Kannan, G., Department of Radiology & Imaging, PSG Institute of Medical Sciences & Research, Tamil Nadu, India

Kerl, J. Matthias, MD, Department of Diagnostic and Interventional Radiology, Goethe University, Frankfurt, Germany

Li, Zhenlin, Department of Radiology, Huaxi University Hospital, Chengdu, Sichuan, P.R. China

Meinel, Felix G., MD, Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Germany

Postma, Alida A., MD, Dept. of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands

Prof. Mohrs, Oliver, MD, Radiologie Darmstadt at Alice-Hospital, Darmstadt, Germany

Prof. Song, Bin, MD, Department of Radiology, Huaxi University Hospital, Chengdu, Sichuan, P.R. China

Rizk, Eddy, Superscan Radiology, New South Wales, Australia

Sanki, Joseph, Superscan Radiology, New South Wales, Australia

Sen, Kamal K., MD, Department of Radiology & Imaging, PSG Institute of Medical Sciences & Research, Tamil Nadu, India

Sudhakar, P., Department of Radiology & Imaging, PSG Institute of Medical Sciences & Research, Tamil Nadu, India

Vargas Lobos, M., MT, Medical Imaging Department, Europa Clinics, Brussels, Belgium

Vogl, Thomas J., MD, Department of Diagnostic and Interventional Radiology, Goethe University, Frankfurt, Germany

Waldman, Boris, BSc, Superscan Radiology, New South Wales, Australia

Wang, Yining, MD, Department of Radiology, Peking Union Medical College, Beijing, P.R. China

Wildberger, Joachim E., MD, Dept. of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands

Wu, Bing, MD, Department of Radiology, Huaxi University Hospital, Chengdu, Sichuan, P.R. China

Zhang, Kai, Department of Radiology, Huaxi University Hospital, Chengdu, Sichuan, P.R. China

Zhao, Jin, Department of Radiology, Huaxi University Hospital, Chengdu, Sichuan, P.R. China

Imprint


www.siemens.com/SOMATOM-Sessions

Order No. A91CT-41020-07M1-7600 | Printed in Germany | CC CT 1655 ZS 1113/25. | © 11.13, Siemens AG Not for distribution in the US.

Global Siemens Healthcare Headquarters

Siemens AG Healthcare Sector Henkestrasse 127 91052 Erlangen Germany Phone: +49 9131 84-0 www.siemens.com/healthcare

Global Siemens Headquarters

Siemens AG Wittelsbacherplatz 2 80333 Munich Germany

On account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some/All of the features and products described herein may not be available in the United States.

The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases.

Siemens reserves the right to modify the design, packaging, specifications and options described herein without prior notice. Please contact your local Siemens sales represen tative for the most current information.

Note: Any technical data contained in this document may vary within defined tolerances. Original images always lose a certain amount of detail when reproduced.


Local Contact Information

Asia/Pacific: Siemens Medical Solutions Asia Pacific Headquarters The Siemens Center 60 MacPherson Road Singapore 348615 Phone: +65 6490 - 6000 www.siemens.com/healthcare

Canada: Siemens Canada Limited Healthcare Sector 2185 Derry Road West Mississauga ON L5N 7A6 Canada Phone: +1 905 819 - 5800 www.siemens.com/healthcare

Europe/Africa/Middle East: Siemens AG Healthcare Sector Henkestraße 127 D-91052 Erlangen Germany Phone: +49 9131 84 - 0 www.siemens.com/healthcare

Global Business Unit

Siemens AG Medical Solutions Computed Tomography & Radiation Oncology Siemensstraße 1 91301 Forchheim Germany Phone: +49 9191 18 - 0 www.siemens.com/healthcare

Latin America: Siemens S.A. Medical Solutions Avenida de Pte. Julio A. Roca No 516, Piso 7 C1067ABN Buenos Aires Argentina Phone: +54 11 4340 - 8400 www.siemens.com/healthcare

USA: Siemens Medical Solutions U.S.A., Inc. 51 Valley Stream Parkway Malvern, PA 19355 -1406 USA Phone: +1-888-826 - 9702 www.siemens.com/healthcare

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