Cardiol Clin 21 (2003) 549–559

Clinical results of minimally invasive coronaryangiography using computed tomography

Stephan Achenbach, MDa,b,c,*, Dieter Ropers, MDc, Karsten Pohle,MDc, Katharina Anders, MDd, Ulrich Baum, MDd, Udo Hoffmann,

MDa, Fabian Moselewskib, Maros Ferencik, MDa,Thomas J. Brady, MDa

aDepartment of Radiology, Massachusetts General Hospital and Harvard Medical School,

55 Fruit Street, Boston, MA 02114, USAbDivision of Cardiology, Massachusetts General Hospital and Harvard Medical School,

55 Fruit Street, Boston, MA 02114, USAcDepartment of Internal Medicine II, University of Erlangen-Nurnberg, Ulmenweg 18, 91054, Erlangen, Germany

dDepartment of Diagnostic Radiology, University of Erlangen, Ulmenweg 18, 91054, Erlangen, Germany

Selective invasive coronary angiography isroutinely performed in a high number of patients.Coronary angiography has high temporal (�5 ms)

and spatial resolution (�0.2 mm), and very highcontrast between the coronary lumen and thesurrounding structures can be achieved because

undiluted contrast medium is selectively injectedinto the coronary arteries. Importantly, treatmentof coronary artery stenoses that were identifiedcan usually be performed in the same session. On

the other hand, the rate of complications ofinvasive coronary angiography, albeit low, is notnegligible, and the cost is high. This has led to

a search for less invasive and cheaper alternativesfor coronary artery visualization and detection ofstenoses. Because of the complex anatomy of the

coronary arteries, only tomographic techniquesare suitable for non-invasive coronary imaging.The small dimensions of the coronary arteries, in

Stephan Achenbach was supported by Deutsche

Forschungsgemeinschaft (DFG) [German Research

Foundation].

* Corresponding author. CIMIT Vulnerable Plaque

Program, Massachusetts General Hospital, 100 Charles

River Plaza, Suite 400, Boston, MA 02114.

E-mail address: Sachenbach@partners.org

(S. Achenbach).

0733-8651/03/$ - see front matter � 2003 Elsevier Inc. All rig

doi:10.1016/S0733-8651(03)00090-0

combination with their incessant and rapidmotion during the cardiac cycle, require highspatial and temporal resolution. In addition,

image acquisition must be synchronized to thecardiac cycle by way of ECG-gating since everyimage will only cover a small portion of the

coronary artery tree, and all images that representthe coronary tree of a given patient must beacquired at the same instance of the cardiac cycle.The potential of magnetic resonance imaging

(MRI) for coronary imaging is being intensivelyinvestigated and explored [1–5]. However, despitethe impressive advances that have been achieved

over the past decade, magnetic resonance stillrequires acquisition and averaging of data overseveral (� 40) heartbeats to generate one image,

which can substantially limit image quality [6]. Inaddition, a sufficient signal-to-noise ratio can onlybe achieved with relatively thick (1.5 mm) slices

that do not provide adequate spatial resolution.Computed tomography (CT) techniques constitutean attractive alternate approach to tomographiccoronary angiography. In particular, electron

beam computed tomography (EBCT) and multi-detector spiral CT (MDCT) have the necessaryspatial and temporal resolution for coronary

imaging. Over the past several years, these techni-ques have evolved to a degree that permits reliablecoronary artery imaging in suitable subsets of

hts reserved.

550 S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

patients, including visualization of the coronaryartery lumen and detection of stenoses. However,the diagnostic accuracy for the presence or absence

of stenoses is limited if image quality is poor.

Methods

EBCT

EBCT is a cross-sectional CT technique thathas very high temporal resolution because nomechanical parts are involved in image acquisi-

tion. Instead, X-rays are created by an electronbeam, which sweeps across fixed tungsten targetsarranged in a semicircular manner around the

patient [7]. Thus, one high-resolution image canbe acquired in 50 to 100 ms. The slice thickness is1.5 or 3.0 mm, with an in-plane resolution of

approximately 7 to 9 line pairs per cm.

MDCT

Modern MDCT systems have an X-ray gantryrotation time of 500 ms or less. Reconstruction

algorithms have been developed which allowcross-sectional image reconstruction from dataacquired during only a part of the X-ray-tube

rotation. Either little more than one-half rotation(= half-scan algorithms) or even smaller portionsof several subsequent rotations (= multi-phase

algorithms) are needed for image reconstruction[8,9,10]. Images can be reconstructed to representcertain time instances during the cardiac cycle byusing the simultaneously recorded ECG informa-

tion. With half-scan reconstruction algorithms,image acquisition windows of approximately 210to 250 ms can be achieved with image data

acquired during one heart beat. This can be suf-ficient to obtain images free of motion artifact inmany patients if the data reconstruction window

is positioned during a suitable phase of the cardiaccycle. Modern MDCT scanners permit simulta-neous data acquisition in 16 parallel cross-sections

with collimations of less than 1 mm. The in-planespatial resolution is approximately nine line pairsper cm.

Patient preparation and data acquisition

Because reliable ECG triggering and a constantlength of the cardiac cycle are crucial for imagequality both in EBCT and MDCT, only patients

in stable sinus rhythm are suitable for CTcoronary angiography. In EBCT studies, the heartrate does not have critical influence on imagequality, but in MDCT, the heart rate should be

less than 60 to 65 beats per minute. Therefore,

many investigators have suggested to routinelyuse premedication with b-receptor–blockingagents. Intravenous injection of X-ray contrast

medium is necessary, therefore, the usual contra-indications and side effects of iodinated contrastmedia apply. The patients should be fasting andmost investigators have suggested the administra-

tion of sublingual nitroglycerine immediatelybefore the scan, to achieve vasodilation of thecoronary arteries. Data acquisition for tomo-

graphic coronary angiography with either CTmethod is performed in two steps. In a first step,a bolus of iodinated contrast agent (eg, 10 mL)

is injected into an antecubital vein to measurethe contrast agent transit time from injection toenhancement of the coronary arteries. Serialimages acquired after the injection permit de-

tection of the onset of opacification within thelumen of the ascending aorta, thus providinga measure of the transit time. In a second step,

a volume image data set is acquired which coversthe complete coronary artery tree. Usually,between 100 and 160 mL of iodinated contrast

agent are injected into an antecubital vein at a flowrate of approximately 4.0 mL/s. Image acquisitionis performed during inspiratory breathhold. After

the initiation of contrast injection, image acquisi-tion begins at the previously determined contrastagent transit time.

In EBCT, serial, overlapping cross-sectional

images are acquired with 3.0 or 1.5 mm slicethickness, prospectively triggered by the ECG(Fig. 1). Images can be acquired up to 5 times

within one cardiac cycle, with the table beingadvanced to a new level after every QRS complex.Thus, approximately 40 to 50 cardiac cycles are

necessary to cover the volume of the heart.Depending on the patient’s heart rate, an EBCTcoronary angiography will typically take between30 and 40 seconds. In MDCT, a continuous spiral

data set is acquired with a collimation between 1.0mm (4-slice systems) and 0.5 mm (16-slice sys-tems). Acquisition of the spiral data set typically

requires approximately 35 s (4-slice systems) to 20s (16-slice systems). The duration of imageacquisition does not depend on the patient’s heart

rate, only on the axial length of the body volumethat needs to be covered (usually �120 mm).Overlapping images are reconstructed with a thick-

ness of 1.0 to 1.3 mm and an increment of 0.5 to1.0 mm (Fig. 2). The diagnosis of coronary arterystenoses is usually made based on the transaxialcross-sectional images and on multiplanar recon-

structions, using interactive display and naviga-

551S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

Fig. 1. (A) Transaxial EBCT image after intravenous injection of contrast agent shows the left main coronary and

bifurcation into left anterior descending coronary artery (large arrow) and circumflex coronary artery (small arrow).

(B) 3-Dimensional shaded surface display (arrow: left anterior descending coronary artery).

tion through the data set on dedicated image

processing workstations. Other 2-dimensional or3-dimensional reconstruction techniques add littleincremental diagnostic value but may be helpful in

presenting the data.

Results

EBCT

Several investigators have compared the accu-racy of EBCT for the detection of coronary arterystenoses to invasive coronary angiography in

various subsets of patients [11–21]. Because theauthors used slightly different image acquisitionprotocols, different forms of image reconstruc-

tion, and different definitions of coronary arterysegments and severity of stenosis, the results ofthese studies cannot be directly compared. Ingeneral, however, the clinical studies have shown

that EBCT can be effective for detection ofcoronary stenoses and occlusions in the proximaland middle segments of coronary vessels. The

sensitivity of EBCT ranged from 74% to 92%with specificities from 66% to 94%. As a majorlimitation, a substantial number of coronary ar-

tery segments could not be evaluated for the pre-sence or absence of stenosis in most of thesestudies because of insufficient image quality. Thiswas in most cases because of either motion artifact

or severe coronary calcifications, and it affected

between 11% and 28% of all coronary artery

segments (Table 1) [12–21]. Consistently, allclinical studies of CT coronary angiographyreported high negative predictive values for the

exclusion of coronary stenoses. All studies pub-lished to date have been performed on oldergenerations of EBCT scanners. In addition, allpublished studies have used 3.0 mm slices, not 1.5

mm slices. The recent introduction of a newEBCT scanner (e-Speed, GE Medical Systems,Milwaukee, Wisconsin) promises further improve-

ments of image quality because of its highertemporal and spatial resolution and reducedimage noise. The effects of these improvements

on diagnostic accuracy remain to be investigated.

MDCT

Since the initial reports on the visualization ofcoronary artery lumen by mechanical multidetec-tor spiral CT in the year 2000 [22,23], several

investigators have contributed to this field andassessed the accuracy of MDCT for the detectionof coronary artery stenoses with 4-slice and

16-slice systems (Table 2) [24–33] in comparisonto selective, invasive angiography (Fig. 3) [33].Again, these studies were performed in differing

patient groups and with various image acquisitionand reconstruction protocols, making these stud-ies difficult to compare. The sensitivity of MDCT

for the detection of significant stenoses ranged

552 S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

Fig. 2. (A) Transaxial 4-slice MDCT image after intravenous injection of contrast agent shows the left main coronary

artery bifurcation into the left anterior descending and left circumflex coronary artery (arrow). (B) Maximum intensity

projection over a slab thickness of 10 mm shows a longer segment of the left anterior descending coronary artery (large

arrow) with side branches (small arrow: diagonal branch). (C) 3-Dimensional, surface-weighted volume rendering

reconstruction viewed from an anterior and cranial aspect shows the left anterior descending coronary artery (large

arrow) and diagonal branch (small arrow).

from 72% to 95%, with specificities from 84% to

97%. Up to 32% of coronary arteries had to beexcluded from analysis, in most cases because ofmotion artifact or, less frequently, because of

calcification (Fig. 4). Several investigators wereable to show that a slow heart rate is a prerequisitefor good image quality in MDCT [28,34–36].

Usually, at heart rates higher than 60 to 65 beatsper minute good image quality and reliabledetection of coronary stenosis cannot be achieved.

Most investigators therefore suggest to routinely

administer b-receptor–blocking agents before thescan to reduce the patient’s heart rate. MostMDCT image reconstruction algorithms use data

from several heartbeats if the heart rate exceedsapproximately 65 to 70 beats per minute. Thefinding that image quality and diagnostic accuracy

tend to be poor with such multisector reconstruc-tions, although the nominal length of the dataacquisition window may be well below 200 ms,

553S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

Table 1

Sensitivity and specificity of contrast-enhanced EBCT for the detection of significant coronary artery stenoses

(comparisons to invasive coronary angiography)

Author Patients Sensitivitya Specificitya Not evaluable

Nakanishi [12] 37 74% 95% –

Schmermund [13] 28 82% 88% 28%

Reddy [14] 23 88% 79% –

Rensing [15] 37 77% 94% 19%

Achenbach [16] 125 92% 94% 25%

Budoff [17] 52 78% 71% 11%

Achenbach [18] 36 92% 91% 20%

Leber [19] 87 78% 93% 24%

Ropers [20] 118 90% 66% 24%

Nikolaou [21] 20 85% 77% 11%

a in evaluable segments.

emphasizes that averaging data of several heartbeats can have deleterious influence on image

quality. The recent introduction of 16-slicesystems has resulted in several significant im-provements [32,33]. The ability to acquire data

with thinner slice collimation improved spatialresolution. Faster rotation times (420 ms) improvetemporal resolution and, along with the largervolume coverage during each gantry rotation,

substantially reduce the overall duration of thescan (from �35 to �20 seconds). This reduces theamount of contrast agent that must be adminis-

tered and greatly shortens the breathhold for thepatient.

Clinical applications

Invasive coronary angiography is not only thecurrent gold standard for the detection ofcoronary stenoses, but also permits interventional

treatment of stenoses immediately following the

diagnostic angiogram. Non-invasive tomographicimaging modalities for coronary artery visualiza-

tion obviously provide no opportunity for treat-ment. Thus, CT coronary angiography seems oflimited value in patients with a high pre-test

likelihood of having stenotic coronary disease (eg,patients with typical chest pain or a positive stresstest). On the other hand, the pre-test likelihood ofcoronary artery stenosis may be lower in other

patient subsets (eg, younger women with atypicalchest pain). If CT coronary angiography permitsreliable exclusion of coronary stenoses, it may be

of potential diagnostic use in such patients.Carefully designed clinical studies will have toaddress this issue. Non-invasive methods for

coronary visualization should be evaluated fortheir use to avoid ‘‘negative’’ invasive coronaryangiograms (ie, angiograms showing findings thatdo not require revascularization therapy).

In addition, EBCT and MDCT have beenshown to reliably permit assessment of coronary

Table 2

Sensitivity and specificity of MDCT (4-slice systems and 16-slice systems) for the detection of coronary artery stenoses

in comparison to invasive coronary angiography

Author Patients Sensitivitya Specificitya Not evaluable

4-slice MDCT

Nieman [25] 31 81% 97% 27%

Achenbach [26] 64 91% 84% 32%

Knez [27] 42 78% 98% 6%

Herzog [28] 42 72% 92% –

Kopp [29] 102 86%–93% 96%–97% 18%

Becker [30] 28 78% 71% 11%

Nieman [31] 53 82% 93% 30%

16-slice MDCT

Nieman [32] 59 95% 86% 0%

Ropers [33] 77 92% 93% 12%

a in evaluable segments.

554 S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

Fig. 3. Patient with a stenosis of the left anterior descending coronary artery (LAD). (A) Transaxial MDCT image

showing the proximal LAD with a partly calcified lumen reduction (arrow). (B) Multiplanar reconstruction orthogonal

to the LAD yields a tomographic view of the lesion (arrow) and shows the eccentric, partly calcified plaque and residual

lumen filled with contrast agent. (C) Invasive angiogram of the same patient which shows the eccentric stenosis of the

LAD. (From Ropers D, Baum U, Pohle K, Anders K, Ulzheimer S, Ohnesorge B, et al. Detection of coronary artery

stenoses with thin-slice multi-detector row spiral computed tomography and multiplanar reconstruction. Circulation

2003;107:664–6; with permission.)

artery bypass grafts for patency versus occlusionand for the presence of stenoses in the body of thegrafts (Fig. 5) [37–41]. Therefore, if the clinical

situation requires assessment only of bypassgrafts, non-invasive imaging might be an option.Assessment of stent patency and of in-stent

restenosis, important questions from a clinicalpoint of view, have been addressed in severalstudies. Despite several optimistic reports [42–45],

it currently appears that stents cannot be reliably

assessed with CT imaging, because artifactscaused by metal prevent adequate visualizationof the vessel lumen inside the stent (similar to the

difficulty of visualization of severely calcifiedcoronary segments). Furthermore, EBCT andMDCT imaging permit reliable visualization

and assessment of anomalous coronary arteriesand coronary fistulas [46–51]. Along with MRI,CT techniques can be regarded the first-line test

for the workup of suspected coronary anomalies.

555S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

Fig. 4. Reasons for inability to evaluate coronary arteries. (A) MDCT: motion artifacts at the level of the mid-segment

of the right coronary artery (arrow). (B) EBCT: severe calcifications in the course of the left anterior descending coronary

artery (arrow).

EBCT imaging also permits reliable visualizationof coronary artery aneurysms in Kawasaki disease

and of aneurysmatic bypass grafts [52,53]. Finally,the use of EBCT and MDCT to evaluate thecoronary venous system has been described [54–

56]. The exact definition of venous anatomy maybe important in the context of new interventional

Fig. 5. Bypass graft visualization. The 3-dimensional

display generated from EBCT image data shows a patent

sequential saphenous vein jump graft to the diagonal

branch (large arrow) and left anterior descending

coronary artery and a patent saphenous vein graft to

the right coronary artery (small arrow).

treatment strategies for coronary artery diseaseand for some electrophysiologic procedures.

Visualization of non-calcified plaque

Recent studies have shown that contrast-

enhanced CT permits the visualization of non-calcified coronary plaque. Even in the absence ofobstructive luminal narrowing, atherosclerotic

lesions could be depicted in contrast-enhancedMDCT and EBT scans (Fig. 6). Leber et al [57]found the ratio of calcified to non-calcifiedplaques to be significantly different in patients

with stable coronary artery disease than in pa-tients with acute myocardial infarction, witha higher prevalence of non-calcified plaques in

myocardial infarction patients. One report in 12patients demonstrated that CT could identifyvarying densities in coronary atherosclerotic

plaques in vivo (Fig. 7) [58]. The investigatorsfound that plaques characterized as ‘‘soft’’ byintravascular ultrasound (IVUS) had a lower

mean CT attenuation (14 � 26 HU) than plaquescharacterized as ‘‘fibrotic’’ (91� 21 HU) or‘‘calcified’’ (419 � 194 HU) [58]. These initial in-vivo observations are corroborated by ex-vivo

data: in 21 specimens of carotid arteries, lipid-richplaques could be distinguished from fibrousplaques by their mean CT attenuation (39 � 12

HU versus 90 � 24 HU) [59] and in ex-vivo heartspecimen, densities of 47 � 9 and 104 � 28 HU,respectively, were found for 33 lipid-rich and

556 S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

Fig. 6. Visualization of a partially calcified atherosclerotic plaque in the left circumflex coronary artery by contrast-

enhanced EBCT (A) (arrow) and of a non-calcified plaque in the left anterior descending coronary artery by MDCT (B)

(arrow).

fibrous plaques [60]. Even though these findings

are intriguing and seem to indicate an opportunityto detect and analyze coronary atheroscleroticplaques non-invasively by CT, it must be empha-

sized that the current knowledge is preliminary.There are no data yet on the sensitivity andspecificity of CT for the direction of non-calcified

plaque or on the ability to quantify non-calcified

Fig. 7. Visualization of a non-calcified atherosclerotic

plaque in the proximal left anterior descending coronary

artery by 4-slice MDCT and corresponding intravascu-

lar ultrasound (IVUS) image (longitudinal reconstruc-

tion of plaque by mechanized IVUS pullback). IVUS

shows a lipid-rich plaque (From Schroeder S, Kopp AF,

Baumbach A, Meisner M, Kuettner A, Georg C, et al.

Noninvasive detection and evaluation of atherosclerotic

coronary plaques with multislice computed tomography.

J Am Coll Cardiol 2001;37:1430–5; with permission.)

plaque, and it is not clear whether non-calcified

plaque assessment will provide a better measure ofoverall coronary atherosclerotic plaque burdenthan the quantification of coronary calcium.

However, given the clinical need for improvedrisk stratification, intensive further research in thisarea is undoubtedly warranted.

Summary

Fast, high-resolution CT techniques, such as

EBCT and MDCT permit imaging of the coro-nary arteries. Continuous improvements in thecapabilities of both technologies for visualization

of the coronary lumen and detection of coronaryartery stenoses are being made. Image qualitycurrently is not robust enough in all patients to

consider non-invasive coronary angiography byEBCT and MDCT a routine clinical tool. Inselected patients and carefully performed, how-ever, they show promise as means to exclude the

presence of coronary artery stenoses in a non-invasive fashion. This may become a beneficialand important application of these technologies.

Other possible applications pertain to smallerpatient subsets, such as patients with anomalouscoronary arteries, fistulas or aneurysms. The

development of techniques to visualize non-calcified plaque is interesting with respect toassessment of coronary risk, but this requires

further investigation.

557S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

References

[1] Manning WJ, Li W, Edelman RR. A preliminary

report comparing magnetic resonance coronary

angiography with conventional angiography. N

Engl J Med 1993;328:828–32.

[2] van Geuns RJ, de Bruin HG, Rensing BJ, Wielo-

polski PA, Hulshoff MD, van Ooijen PM, et al.

Magnetic resonance imaging of the coronary arteries:

clinical results from three dimensional evaluation of

a respiratory gated technique.Heart 1999;82:515–93.

[3] Wielopolski PA, van Geuns RJM, de Feyter PF,

Oudkerk M. Breath-hold coronary MR angiograpy

with volume-targeted imaging. Radiology 1998;209:

209–19.

[4] Regenfus M, Ropers D, Achenbach S, Kessler W,

Laub G, Daniel WG, et al. Noninvasive detection

of coronary artery stenosis using contrast-enhanced

three-dimensional breath-hold magnetic resonance

coronary angiography. J Am Coll Cardiol 2000;

36:44–50.

[5] Kim WY, Danias PG, Stuber M, Flamm SD, Plein

S, Nagel E, et al. Coronary magnetic resonance

angiography for the detection of coronary stenoses.

N Engl J Med 2001;345:1863–9.

[6] Achenbach S, Daniel WG. Noninvasive coronary

angiography - an acceptable alternative? N Engl J

Med 2001;345:1909–10.

[7] Gould RG. Principles of ultrafast computed to-

mography: Historical aspects, mechanism, and

scanner characteristics. In: Stanford W, Rumberger

JA, editors. Ultrafast computed tomography in

cardiac imaging: principles and practice. Mt Kisko,

New York: Futura; 1992. p. 1–16.

[8] Kachelrieß M, Ulzheimer S, Kalender WA. ECG-

correlated image reconstruction from subsecond

multi-slice spiral CT scans of the heart. Med Phys

2000;27:1881–90.

[9] Flohr T, Ohnesorge B. Heart-rate adaptive optimi-

zation of spatial and temporal resolution for ECG-

gated multi-slice spiral CT of the heart. J Comput

Assist Tomogr 2001;25:907–23.

[10] Flohr T, Bruder H, Stierstorfer K, Simon J, Schaller

S, Ohnesorge B. New technical developments

in multislice CT, part 2: Sub-millimeter 16-slice

scanning and increased gantry rotation speed for

cardiac imaging. Fortschr Rontgenstr 2002;174:

1022–7.

[11] Moshage W, Achenbach S, Seese B, Bachmann K,

Kirchgeorg M. Coronary artery stenoses: three-

dimensional imaging with electrocardiographically

triggered, contrast agent-enhanced, electron beam

CT. Radiology 1995;196:707–14.

[12] Nakanishi T, Ito K, Imazu M, Yamakido M.

Evaluation of coronary artery stenoses using

electron-beam CT and multiplanar reformation.

J Comp Assist Tomogr 1997;21:121–7.

[13] Schmermund A, Rensing BJ, Sheedy PF, Bell MR,

Rumberger JA. Intravenous electron-beam com-

puted tomographic coronary angiography for seg-

mental analysis of coronary artery stenoses. J Am

Coll Cardiol 1998;31:1547–54.

[14] Reddy GP, Chernoff DM, Adams JR, Higgins CB.

Coronary artery stenoses: assessment with contrast-

enhanced electron-beam CT and axial reconstruc-

tions. Radiology 1998;208:167–72.

[15] Rensing BJ, Bongaerts A, van Geuns RJ, van

Ooijen P, Oudkerk M, de Feyter PJ. Intravenous

coronary angiography by electron beam computed

tomography. A clinical evaluation. Circulation

1998;98:2509–12.

[16] Achenbach S, Moshage W, Ropers D, Nossen J,

Daniel WG. Value of electron-beam computed

tomography for the detection of high-grade coro-

nary artery stenoses and occlusions. N Engl J Med

1998;339:1964–7.

[17] Budoff MJ, Oudiz RJ, Zalace CP, Bakhsheshi H,

Goldberg SL, French WJ, et al. Intravenous three-

dimensional coronary angiography using contrast-

enhanced electron beam computed tomography.

Am J Cardiol 1999;83:840–5.

[18] Achenbach S, Ropers D, Regenfus M, Muschiol G,

Daniel WG, Moshage W. Contrast-enhanced elec-

tron-beam CT to analyze the coronary arteries in

patients after acute myocardial infarction. Heart

2000;84:489–93.

[19] Leber AW, Knez A, Mukherjee R, White C, Huber

A, Becker A, et al. Usefulness of calcium scoring

using electron beam computed tomography and

noninvasive coronary angiography in patients with

suspected coronary artery disease. Am J Cardiol

2001;88:219–23.

[20] Ropers D, Regenfus M, Stilianakis N, Birke S,

Kessler W, Moshage W, et al. A direct comparison

of noninvasive coronary angiography by electron

beam tomography and navigator-echo-based

magnetic resonance imaging for the detection of

restenosis following coronary angioplasty. Invest

Radiol 2002;37:386–92.

[21] Nikolaou K, Huber A, Knez A, Becker C, Bruening

R, Reiser M. Intraindividual comparison of con-

trast-enhanced electron-beam computed tomogra-

phy and navigator-echo-based magnetic resonance

imaging for noninvasive coronary artery angiogra-

phy. Eur Radiol 2002;12:1663–71.

[22] Ohnesorge B, Flohr T, Becker C, Kopp AF,

Schoepf UJ, Baum U. Cardiac imaging by means

of electrocardiographically gated multisection

spiral CT: initial experience. Radiology 2000;217:

564–71.

[23] Achenbach S, Ulzheimer S, Baum U, Kachelriess

M, Ropers D, Giesler T, et al. Noninvasive

coronary angiography by retrospectively ECG-

gated multislice spiral CT. Circulation 2000;102:

2823–8.

[24] Gerber TC, Kuzo RS, Lane GE, O’Brien PC,

Karstaedt N, Morin RL, et al. Image quality in a

standardized algorithm for minimally invasive

558 S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

coronary angiography with multislice spiral

computed tomography. J Comp Assist Tomogr

2003;27:62–8.

[25] Nieman K, Oudkerk M, Rensing BJ, van Ooijen P,

Munne A, van Geuns RJ, et al. Coronary angi-

ography with multi-slice computed tomography.

Lancet 2001;357:599–603.

[26] Achenbach S, Giesler T, Ropers D, Ulzheimer S,

Derlien H, Schulte C, et al. Detection of coronary

artery stenoses by contrast-enhanced, retrospectively

ECG-gated, multi-slice spiral CT. Circulation 2001;

103:2535–8.

[27] Knez A, Becker CR, Leber A, Ohnesorge B, Becker

A, White C, et al. Usefulness of multislice spiral

computed tomography angiography for determina-

tion of coronary artery stenoses. Am J Cardiol

2001;88:1191–4.

[28] Herzog C, Abolmaali N, Balzer JO, Baunach S,

Ackermann H, Dogan S, et al. Heart-rate-adapted

image reconstruction in multidetector-row cardiac

CT: influence of physiological and technical pre-

requesite on image quality. Eur Radiol 2002;12:

1670–8.

[29] Kopp AF, Schroeder S, Kuettner A, Baumbach A,

Georg C, Kuzo R, et al. Non-invasive coronary

angiography with high resolution multidetector-row

computed tomography. Results in 102 patients. Eur

Heart J 2002;23:1714–25.

[30] Becker CR, Knez A, Leber A, Treede H, Ohnesorge

B, Schoepf UJ, et al. Detection of coronary artery

stenoses with multislice helical CT angiography.

J Comp Assist Tomogr 2002;26:250–5.

[31] Nieman K, Rensing BJ, van Geuns RJ, Munne A,

Ligthart JM, Pattynama PM, et al. Usefulness

of multislice computed tomography for detecting

obstructive coronary artery disease. Am J Cardiol

2002;89:913–8.

[32] Nieman K, Cademartiri F, Lemos PA, Raaijmakers

R, Pattynama PM, de Feyter PJ. Reliable non-

invasive coronary angiography with fast submilli-

meter multislice spiral computed tomography.

Circulation 2002;106:2051–4.

[33] Ropers D, Baum U, Pohle K, Anders K, Ulzheimer

S, Ohnesorge B, et al. Detection of coronary artery

stenoses with thin-slice multi-detector row spiral

computed tomography and multiplanar reconstruc-

tion. Circulation 2003;107:664–6.

[34] Giesler T, Baum U, Ropers D, Ulzheimer S,

Wenkel E, Mennicke M, et al. Noninvasive

visualization of coronary arteries using contrast-

enhanced multidetector CT: Influence of heart rate

on image quality and stenosis detection. Am J

Roentgenol 2002;179:911–6.

[35] Schroeder S, Kopp AF, Kuettner A, Burgstahler C,

Herdeg C, Heuschmid M, et al. Influence of heart

rate on vessel visibility in noninvasive coronary

angiography using new multislice computed tomog-

raphy. Experience in 94 patients. Journal of Clinical

Imaging 2002;26:106–11.

[36] Nieman K, Rensing BJ, van Geuns RJ, Vos J,

Pattynama PM, Krestin GP, et al. Non-invasive

coronary angiography with multislice spiral com-

puted tomography: impact of heart rate. Heart

2002;88:470–4.

[37] Achenbach S, Moshage W, Ropers D, Nossen J,

Bachmann K. Noninvasive, three-dimensional visu-

alization of coronary artery bypass grafts by

electron beam tomography. Am J Cardiol 1997;

79:856–61.

[38] Ropers D, Ulzheimer S, Wenkel E, Baum U,

Giesler T, Derlien H, et al. Investigation of

aortacoronary artery bypass grafts by multislice

spiral computed tomography with electrocardio-

graphic-gated image reconstruction. Am J Cardiol

2001;88:792–5.

[39] Ha JW, Cho SY, Shim WH, Chung N, Jang Y, Lee

HM, et al. Noninvasive evaluation of coronary

artery bypass graft patency using three-dimensional

angiography obtained with contrast-enhanced elec-

tron beam CT. Am J Roentgenol 1999;172:1055–9.

[40] Hoshi T, Yamauchi T, Kanauchi T, Konno M,

Imai K, Suwa J, et al. Three-dimensional computed

tomography angiography of coronary artery bypass

graft with electron beam tomography. J Cardiol

2001;38:197–202.

[41] Lu B, Dai RP, Zhuang N, et al. Noninvasive

assessment of coronary artery bypass graft patency

and flow characteristics by electron-beam tomogra-

phy. J Invasive Cardiol 2002;14:19–24.

[42] Lu B, Dai R, Bai H, Budoff MJ. Detection and

analysis of intracoronary artery stent after PTCA

using contrast-enhanced three-dimensional electron

beam tomography. J Invasive Cardiol 2000;12:1–6.

[43] Pump H, Mohlenkamp S, Sehnert CA, Schimpf SS,

Schmidt A, Erbel R, et al. Coronary arterial stent

patency: assessment with electron-beam CT. Radi-

ology 2000;214:447–52.

[44] Mohlenkamp S, Schmermund A, Haude M, Baum-

gart D, Gorge G, Gronemeyer D, Seibel R, et al.

Non-invasive assessment of coronary Palmaz-Schatz

stents by contrast enhanced electron beam computed

tomography. Eur Heart J 1996;17:1546–53.

[45] Storto ML, Marano R, Maddestra N, Caputo M,

Zimarino M, Bonomo L. Multislice spiral com-

puted tomography for in-stent restenosis. Circula-

tion 2002;105:2005.

[46] Ropers D, Moshage W, Daniel WG, Jessl J,

Gottwik M, Achenbach S. Visualization of coro-

nary artery anomalies and their anatomic course by

contrast-enhanced electron beam tomography and

three-dimensional reconstruction. Am J Cardiol

2001;87:193–7.

[47] Ropers D, Gehling G, Pohle K, Maeffert R,

Regenfus M, Moshage W, et al. Anomalous course

of the left main or left anterior descending coronary

artery originating from the right sinus of valsalva -

identification of four common variants by electron

beam tomography. Circulation 2002;105:e42–43.

559S. Achenbach et al / Cardiol Clin 21 (2003) 549–559

[48] Lee ML, Chiu IS, Chen SJ, Chaou WT. Imaging

characteristics of anomalous left coronary artery

from the pulmonary artery. J Thorac Imaging

2002;17:96–100.

[49] B Brandt-Pohlmann M, Achenbach S, Pougratz G,

Moshage W, Wortmann A. Non-invasive diagnosis

of a congenital coronary artery fistula. Int J Card

Imaging 1998;14:211–4.

[50] Schiele TM, Weber C, Rieber J, Konig A, Theisen

K, Leinsinger G, et al. Images in cardiovascular

medicine. Septal course of the left main coronary

artery originating from the right sinus of Valsalva.

Circulation 2002;105:1511–2.

[51] Yoshimura N, Hamada S, Takamiya M, Kuribaya-

shi S, Kimura K. Coronary arteries anomalies

with a shunt: evaluation with electron-beam CT.

J Comput Assist Tomogr 1998;22:682–6.

[52] Tomita H. Intravascular ultrasound and electron

beam tomography of developing coronary artery

aneurysms after Kawasaki disease. Catheter Car-

diovasc Interv 1999;47:114–5.

[53] Johnson PR, Truitt TD. Saphenous vein coronary

artery bypass graft aneurysm demonstrated by

electron beam CT. J Comput Assist Tomogr

1994;18:488–91.

[54] Gerber TC, Sheedy PF, Bell MR, Hayes DL,

Rumberger JA, Behrenbeck T, et al. Evaluation of

the coronary venous system using electron beam

computed tomography. Int J Cardiovasc Imaging

2001;17:65–75.

[55] Schaffler GJ, Groell R, Peichel KH, Rienmuller R.

Imaging the coronary venous drainage system using

electron-beam CT. Surg Radiol Anat 2000;22:

35–9.

[56] Gerber TC, Kuzo RS. Persistent left superior vena

cava demonstrated with multislice spiral computed

tomography. Circulation 2002;105:e79.

[57] Leber A, Knez A, White CR, Becker A, von Ziegler

F, Muehling O, et al. Composition of coronary

atherosclerotic plaques in patients with acute

myocardial infarction and stable angina pectoris

determined by contrast-enhanced multislice com-

puted tomography. Am J Cardiol 2003;91:714–8.

[58] Schroeder S, Kopp AF, Baumbach A, Meisner M,

Kuettner A, Georg C, et al. Noninvasice detection

and evaluation of atherosclerotic coronary plaques

with multislice computed tomography. J Am Coll

Cardiol 2001;37:1430–5.

[59] Estes JM, Quist WC, Lo Gerfo FW, Costello P.

Noninvasive characterization of plaque morphol-

ogy using helical computed tomography. J Cardio-

vasc Surg (Torino) 1998;39:527–34.

[60] Becker CR, Nikolaou K, Muders M, Babaryka G,

Crispin A, Schoepf UJ, et al. Ex vivo coronary

atherosclerotic plaque characterization with multi-

detector-row CT. Eur Radiol 2003;9:2094–8.