somatom sessions 03
TRANSCRIPT
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s
Case Reports
from
multislice CT SOMATOM
Volume Zoom
SOMATOMS E S S I O N S
S P E C I A L I S S U E I I
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This is the second special issue of Siemens SOMATOM
Sessions with case reports from the early users of
our new multislice CT: SOMATOM Volume Zoom. This
special issue focuses on presenting the clinical results on
the improvement of the spatial resolution of the diagnostic
images especially by using the UHR (Ultra High Resolu-
tion) technique and 0.5 mm slice collimation. On the other
hand, it also shows you the improvement of the routine
applications on CTA and soft tissue studies.
As always we would appreciate your suggestions and
comments.
Special thanks to Dr. Roman Fishbach for his valuable
assistance.
Xiaoyan Chen, M.D.
Editor of SOMATOM Sessions
From the Editor
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Contents
Letter from the Editor Page 2
Petrous Bone (Case 1)
Ulrich Baum, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 4
Petrous Bone (Case 2)
Ulrich Baum, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 6
SinusesUlrich Baum, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 8
Lung Fibrosis
Micheal Lell, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 10
Thoracic Spine
Ulrich Baum, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 12
Thoracic Cord Herniation Through Ventral Dural Defect
Daniel A. Finelli, M.D.
Section of Neuroradiology,The Cleveland Clinic Foundation Page 14
Wrist
Micheal Lell, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 16
Bilateral Renal Angiomyolipoma
Cheng Hong, MD, Roland Bruening, MDKlinikum Grosshadern, University of Munich Page 18
Supraglottic and Glottic Larynx Cancer
Cheng Hong, MD, Roland Bruening, MD
Klinikum Grosshadern, University of Munich Page 20
Squamous Cell Carcinoma of the Oropharynx
Micheal Lell, MD
Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 22
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History:64-year-old female patient with a hearing deficit on
the right side for the last 6 months.The computed tomo-
graphy exam was performed in clinical suspicion of a
cholesteatoma on the right side.
Technical data:
Results:Computed tomography confirms the suspicion of a
cholesteatoma on the right side.There is a small formation
at the top of the middle ear and the external auditory
canal. The malleoincudal articulation is fixed by the tumor.
This is more impressive in the coronal plane than in the
axial plane. In axial plane there is only the suspicion of
fixation of the auditory ossicles over a short distance; in
the coronal plane you can clearly see that the malleolusis fixed by the tumor over a long distance.The anatomy of
the inner ear and the mastoid cells are normal.
Comments:In another case (case 2) we reported about a new special
scan mode called UHR (Ultra High Resolution) implemented
in the SOMATOM Volume Zoom. Ultra High Resolution
improves the spatial resolution in the scan plane but not in
the longitudinal axis. A further improvement implementedin the SOMATOM Volume Zoom is the reduced slice colli-
mation of 0.5 mm. 0.5 mm slices allow an improved spatial
resolution along the longitudinal axis. A slice thickness of
0.5 mm means nearly isotropic imaging of petrous bone
with a voxel size of 0.2 x 0.2 x 0.5 mm 3 and improves the
visibility of details in the multiplanar reconstructions.
Petrous Bone
Scan
Region Petrous bone
Scan length 40 mm
Slice collimation 2 x 0.5 mm
Table feed/rotation 1 mm
Pitch 1
Scan direction caudocranial
Rotation time 0.75 s
kV 140
mAs 200
Kernel U80
Scan time 62 s
Image reconstruction
Reconstructed slice width 0.5 mm
Reconstruction increment 0.3 mm
Postprocessing
Multiplanar reformations +
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Fig. 2: Multiplanar reformations.
Isotropic imaging allow high resolution MPR without
step artifacts. The MPR show the contact of the tumor
a b
Fig.1: Axial plane.
Sharp delineation of the malleoincudal articulation,
the inner ear, the canal for facial nerve and the mastoid.
Soft tissue formation at the top of the middle ear.
A differentiation of tumor parts in the external auditory
canal and the middle ear is not possible.
Osteodestruction cannot be excluded. Fixation of the
auditory ossicles is suspected.
to the auditory ossicles and the extent in the middle
ear and the external auditory canal.
ba
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History:54-year-old male patient with hearing deficiency
(more pronounced on the left side than on the right).
Technical data:
Results:The anatomy of the inner, middle ear and the mastoid cells
are normal. CT can rule out a capsular otosclerosis.
Comparison of high and ultra high resolution images
demonstrates a much better delineation of the ossicular
chain in the middle ear, the ossicular joints and the bone
structure of the mastoid.
Comments:UHR stands for Ultra High Resolution. This is a special
scan mode implemented in the SOMATOM Volume Zoom
the new multislice spiral CT scanner from Siemens. In
addition to the normal detector collimator, a special proce-
dure has been developed for fine collimation. This allows to
achieve the ultra high resolution of bony structures within
a 25 cm scan FOV. Besides, the shorter scan time (0.75 s)
also reduces the motion artifacts and improves the visibilityof detail (better delineation of the ossicular chain, the semi-
circular canals and the cochlea).
Petrous Bone
Scan
Region Petrous bone*
Scan length 46 mm
Slice collimation 4 x 1 mm
Table feed/rotation 2.7 mm
Pitch 2.7
Scan direction caudocranial
Rotation time 0.75 s
kV 140
mAs 140
Kernel U80/H70
Scan time 14.7 s
Image reconstruction
Reconstructed slice width 1 mm
Reconstruction increment 0.5 mm
Postprocessing
Multiplanar reformations +
* The same region was scanned twice with the same
parameter in UHR (Ultra High Resolution) mode and
normal HiRes mode.
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Fig. 1: Superiorsemicircular canal.Normal anatomy.
Fig. 1a without, Fig. 1b with UHR.
Fig. 2: Internal auditory canal and lateral semicircular.
Normal anatomy. Fig. 2a without,Fig. 2b with UHR.
Fig. 4: Cochlea and malleoincudal articulation.
Normal anatomy. Fig. 4a without,Fig. 4b with UHR.
Fig. 5: MPR (Coronal).
Fig. 5a without, Fig. 5b with UHR.
a b a b
Fig. 3: Malleoincudal articulation. Normal anatomy.
Fig. 3a without, Fig. 3b with UHR.
a b a b
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History:A 12-year-old male patient has a history of surgery on
bilateral cholesteatoma. CT was performed to rule
out a recurrent cholesteatoma. Furthermore a chronic
sinusitis was suspected.
Technical data:
Results:After prosthetic stapedectomy, a recurrent cholesteatoma
is found on the left side, while normal postoperative findings
after tympanoplasty on the right. Multiplanar reformations
of the paranasal sinuses allow ruling out thickening of the
mucosa or polyps in the sinuses.
Comments:The conventional rule of the petrous bone study with singleslice CT was oriented parallel to the orbito-meatal line,
and the sinus study was performed in the coronal plane in
order to visualize the fine bony structures in the axial plane
(floor of the orbit, cribrose plate). This was because the
image quality of the secondary multiplanar reformations was
not optimal, i. e. the stepping artifacts were not avoidable
completely. Therefore, the gantry tilt has to be applied, the
scan has to be performed twice (axial and coronal) and
the patient has to undergo a difficult positioning for coronalscan.
The UHR mode with the SOMATOM Volume Zoom allows
imaging of the petrous bone with Ultra High Resolution
in the axial plane as well as optimal coronal reformations
of the middle ear and the paranasal sinuses. The image
quality of the multiplanar reformations is comparable to the
direct coronal scan without noticeable stepping artifacts.
Assessment of bony structures parallel to the axial plane
becomes possible.Therefore, a second examination in theaxial and coronal plane is no longer necessary for studies
involving the midface and the petrous bone (axial slice
orientation) as well as the base of the skull, the floor of the
orbit or the hard palate (coronal slice orientation).
Sinuses
Scan
Region frontal sinus to alveolar
body of maxilla
Scan length 108 mm
Slice collimation 4 x 1mm (UHR mode*)
Table feed/rotation 2.7 mm
Pitch 2.7
Scan direction craniocaudal
Rotation time 0.75 s
kV 140
mAs 165
Kernel U80
Scan time 20 s
Image reconstruction
Reconstructed slice width 1 mm
Reconstruction increment 0.5 mm
Postprocessing
Multiplanar reformations +
* Ultra High Resolution mode
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Fig. 1: Axial image.
Ethmoidal sinuses. Normal anatomy.
Fig. 2: Coronal MPR.
Maxillary and ethmoidal sinuses. Assessment of the
base of skull and the orbital floor without stepping or
metal artifacts.
Fig. 4: Coronal MPR (right side).
Tympanoplasty Typ V.
Correct attachment of the tympanoplasty.
Fig. 3: Coronal MPR (left side).
Metallic stapes prothesis after postsurgical defect
of the auditory ossicles. Cholesteatoma around the
prothesis.
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ung Fibrosis
History:69-year-old female patient suffering from progressive
dyspnea since six months. Decreased physical performance
formonths, Raynauds phenomenon for over 20 years,
pronounced dryness of mouth and eyes. Slow recovery
after a febrile infection. The patient complains of left sided
discomfort associated with breathing, which is most
pronounced with deep inspiration.The conventional chest
X-ray shows an increased interstitial pattern in the leftlower lobe and a left sided pleural effusion. Unremarkable
bronchoscopy, increased lymphocyte count with increased
CD4/CD8 ratio in the bronchoalveolar lavage. Pulmonary
function test revealed a slightly decreased diffusion capacity.
Technical data: Results:Enlarged mediastinal and left hilar lymph nodes. Streaky
peribronchial thickening in the left lower lobe, left sided
pleural effusion. The high resolution images show bilateralmicro nodules and ground glass opacities.
Diagnosis: Pulmonary involvement in systemic sclerosis
with secondary Sjgrens syndrome. Pulmonary fibrosis
after left lower lobe pneumonia.
Comments:The so called Combi-Scan, the acquisition of a high
resolution volume data set with reconstruction of imagesof different slice thickness yields conventional and high-
resolution CT images from one scan.This results in
decreased radiation exposure, a gap free HR-CT data set,
and thus optimal conditions for 2D and 3D image post-
processing.
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Scan
Region apex of the lung to adrenal glands
Scan length 272 mm
Slice collimation 4 x1 mm
Table feed/rotation 6 mm
Pitch 6
Scan direction caudocranial
Rotation time 0.5 s
kV 140
mAs 165
Kernel B50/B30
Scan time 23.35 s
Contrast Injection
Volume 120 ml (non-ionic contrast medium)
Concentration 300 mg iodine/ml
Flow rate 2.5 ml/s
Start delay 50 s
Image reconstruction
Reconstructed slice width 1.25 mm/5 mm
Reconstruction increment 1 mm/2.5 mm
Postprocessing
Multiplanar reformations +
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Fig. 1a: Coronal MPR, slice width 1.25 mm.
Fibrotic changes in left lower lobe.
Clear delineation of bronchi and interlobes.
Fig. 2a: Enlarged lymph nodes in the upper
mediastinum.
Fig. 2b: Axial image (high resolution) showing
inhomogenous distribution of ground glass opacities
and fibrotic changes in left lower lobe.
Fig. 3: Sagittal MPR
Peribronchial thickening and ground glass opacities
indicating active process.
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a b
Fig. 1b: Coronal MPR, slice width 5 mm.
Degradation of image quality due to reduced
z-resolution.
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History:52-year-old female patient with known bone metastases
from breast carcinoma. The MR study of the thoracic spine
indicates loss of height of several vertebras in the middle
section. Forplanning of possible surgery or radiation therapy
a CT study of the spine was required.
Technical data:
Results:CT shows a diffuse mixed osteolytic and osteosclerotic
metastatic involvement of the entire thoracic spine,
predominately affected are the 2nd, 4th, 7th, 11th and 12th
vertebras. Metastases are found not only in the vertebral
bodies but also in the pedicles and spinous processes.
Sagittal MPRs show a slight ventral compression of the
anterior part of the 7th vertebra, but normal height of the
posterior part. Sagittal MPR further exclude significant lossof vertebral body height of the other vertebras.
Comments:Multislice spiral CT makes it possible to scan a large
section of the spine (e.g. the entire thoracic segment) with
high, almost isotropic resolution.This provides optimal
secondary image reformations (e.g. MPR, SSD).
Indications for large section with high resolution imaging
of the spine are found in trauma cases and for therapyplanning (surgery, radiation therapy) in bone metastases
as well.
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Thoracic Spine
Scan
Region first thoracic vertebra to
first lumbar vertebra
Scan length 273 mm
Slice collimation 4 x 1 mm
Table feed/rotation 4 mm
Pitch 4
Scan direction craniocaudal
Rotation time 0.75 s
kV 140
mAs 210
Kernel B60
Scan time 59 s
Image reconstruction
Reconstructed slice width 1 mm/3 mm
Reconstruction increment 1 mm/3 mm
Postprocessing
Multiplanar reformations +
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Fig. 1: Sagittal MPR.
The sagittal MPRs show diffuse osteolytic metastases
of the thoracic spine and additionally osteosclerotic
metastases of the 2nd, 4th, 7th, 11th and12th vertebral body.
Slight compression of the anterior part, but exclusion
of loss of height of the posterior part of the 7th vertebra
(b). Normal width of the spinal cord.
Fig. 3: Axial image.
Osteosclerotic metastases of the right part of the
vertebral body, both posterior pedicle and the left rib.
Normal width of the spinal canal.
Fig. 2: Axial image.
Osteosclerotic metastases of the body of the vertebral
body and the right posterior pedicle. No stenosis of the
spinal canal.
a
b
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History:The patient is a 67-year-old woman who had experienced
progressive left sided pain, numbness, and burning sen-
sation, extending from her mid chest level to the left leg and
foot over the past nine months. She also had right sided
leg weakness, especially in the knee and hip regions.These
symptoms were making it very difficult for the patient to
walk, and she had sustained several falls, though without
serious injury.The patient had been evaluated by severalneurology and spine surgery consultants at another insti-
tution, who felt her constellation of symptoms, referred to
as a Brown-Sequard Syndrome, suggested a right sided
spinal cord lesion at the T8-9 level.The patient had an
extensive workup including spinal tap, electromyographic
(EMG) studies, MRI scans of thoracic and lumbar spine,
and thoracolumbar myelogram with CT myelography,
without reaching a definitive diagnosis, but her physicians
felt they had excluded a compressive, neoplastic, or other
surgical lesion.
The patient was referred to CCF for another opinion, and
on neurologic examination was felt to again have symptoms
suggesting a Brown-Sequard Syndrome, however likely
at a higher level, approximately T4. Review of the outside
MRI studies demonstrated a local anterior and rightward
deviation in the position of the spinal cord at T4, with a
deformed local contour of the cord, and an associated thin
collection of fluid in the anterior epidural space; findings
which had not been appreciated previously.The outsidethoracolumbar myelogram and CT was found to have been
targeted at the T8 level, and did not include adequate
evaluation of the upper thoracic levels. The MR findings were
quite suspicious for the rare clinical condition of a ventral
spinal cord herniation through a dural defect.
Technical data:For optimal further evaluation, confirmation, and pre sur-
gical planning, the decision was made to perform another
thoracic myelographic study, targeted at the T4 level, with
post myelographic, high resolution spiral CT study on
the Siemens SOMATOM Volume Zoom scanner. The high
speed, high resolution attributes of the multislice array
allowed a1 mm spiral dataset to be obtained in a single
breathhold. This yielded an extremely detailed, artifact-freeset of images and multiplanar reconstructions for neuro-
radiologic analysis and surgical planning, far superior to the
patients prior CT or MRI studies.
Results:The study clearly demonstrated the ventral, right-sided
dural defect at T4-5, with contrast laden CSF both in the
thecal sac, and in the anterior, epidural CSF collection, thus
clearly outlining the dural margins. The thoracic spinal cordwas shown to be herniated into and partially through the
dural defect. The cord was deformed locally, with the CT
myelographic study clearly demonstrating a pinching
of the cord at the margins of the dural tear.The study also
showed that the T4-5 disk space was abnormal, with
evidence of a remote right sided disk herniation, which had
healed. This was likely the cause of the dural tear.
The patient was taken to surgery, where T4-5 laminectomy
was performed. The dorsal thecal sac dura was incised,exposing the spinal cord, which was carefully freed from
the herniation. A 2 cm long tear in the anterior dura was
found and repaired, and the dorsal dural incision was closed.
The patient had an uneventful post operative course,
and had an improvement in her neurologic deficits on the
first postoperative day. She is now three weeks post-op,
has undergone physical therapy, and has experienced near
complete resolution of her symptoms.
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Thoracic Cord Herniation Through Ventral Dural Defect
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Fig. 1a: Axial post-myelographic CT image at the
level of T6 demonstrates the anteriorextradural fluid
collection containing myelographic contrast-laden
cerebrospinal fluid, clearly outlining the ventral dura.
Fig. 1b: Axial CT image at T4-5,shows the ventral,
right-sided dural defect, with herniation of the thoracic
spinal cord through the defect, causing pinching and
local deformity of the cord.
Fig. 1c, and Fig. 1d: parasagittal multiplanar recon-
struction of the axial CT data shows the local deviation
and deformity of the spinal cord at T4-5,where it is
herniated through the 2 cm cranio-caudal dimension
d
ba
c
dural defect, centered at the disk space. Note the
deformity of the upper end plate of T5, and the mild
ventral impression due to remote disk protrusion,
which was suspected to be the cause of the dural tear.
Zoom, allowed the diagnosis of a rare spinal cord
abnormality, the treatment of which kept a patient from
becoming wheelchair bound.
SummaryIn this case, the combination of clinical, surgical, and neuro-
radiological expertise of CCF physicians, coupled with the
imaging capabilities of the Siemens SOMATOM Volume
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History:A 36-year-old patient who fell playing squash. Moderate
swelling and pain of the wrist, typical triggerpoint at
Tabatir. Suspected fissure of the scaphoid on conventional
X-ray. After temporary immobilization, a CT scan was per-
formed to confirm diagnosis.
Technical data:
Results:Fracture in the middle third of the scaphoid bone without
fragment dislocation.
CT scan was performed with patient lying prone, immo-
bilized arm over head, longitudinal axis of scaphoid in
scan plane. Despite plaster, good image quality could be
achieved. With the high resolution achieved by using
the Ultra High Resolution mode (UHR), subtle assessmentof the trabecular bone is possible. Thin slices with small
reconstruction increment is the basis for optimal 2D and
3D imaging. MPRs in sagittal and coronal plane allow easy
recognition of anatomy and exact assessment of joints.
Interactive volume rendering, especially with stereoscopic
view, creates a spectacular view of the anatomy and the
fragments, helping both patients and surgeons to visualize
the pathology in 3-dimension.
Wrist
Fig. 1: Axial images show fracture in the middle third
of the scaphoid.
Scan
Region distal radioulnar articula-
tion to metacarpal bones
Scan length 44 mm
Slice collimation 4 x 1mm (UHR* mode)
Table feed/rotation 3 mm
Pitch 3
Scan direction craniocaudal
Rotation time 0.75 s
kV 120
mAs 90
Kernel U80
Scan time 12.2 s
Image reconstruction
Reconstructed slice width 1 mm
Reconstruction increment 0.3 mm
Postprocessing
Multiplanar reformations +
VRT +
* Ultra High Resolution
1
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Fig. 2 and 3: Multiplanar reformations in planes
parallel to the radial bone and in the radio-ulnar plane,
Fig. 4 and 5: Volume rendering can create opaque and
transparent image of the scaphoid and the relation of
the fragments.
demonstrate fracture, allowing exact assessment of
the joints and fragments.
2 3
4 5
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Bilateral Renal Angiomyolipoma
History:A 34-year-old male presented with a one-year history of
abdominal pain. He described this pain as being cramping
at times, easing off when walking around. He felt that his
abdomen had become swollen and heavy over the previous
2 months. In the clinical examination, a huge soft mass
was found in the abdomen. Ultrasound examination showed
large masses in both kidneys. An abdominal CT was per-
formed.
Technical data:Abdominal spiral scanning with a multislice spiral CT scanner
(SOMATOM Volume Zoom, Siemens Medical Engineering,
Forchheim, Germany), and multiplanar reformations (MPR).
Results and comments:Angiomyolipomas are seen on CT as circumscribed renal
masses. The presence of intratumoral fat is almost diag-
nostic of angiomyolipomas. Problems in diagnosis occur
when angiomyolipomas are composed predominantly of
muscle or vascular tissue and contain only minimal amounts
of fat. Such small amounts of fat can be easily overlooked
unless searched for carefully in the CT study. The recentmultislice CT technology offers the potential to cover much
larger anatomic areas without sacrificing image resolution
or quality and to clearly identify the fat-containing areas
when compared to the single slice CT technology. This is
evident in this case (Fig.1).
The thin slice (4*1 mm) acquisition and reconstruction
(1.25 mm) with an increment of 0.8 mm (36 % overlap) pro-
vide the possibility to achieve a high quality coronal MPR
image (Fig. 2). This allowed us to evaluate the abdominalmass and determine the relationship between the mass
and its surrounding structures so that we could provide
clearer diagnostic information for the surgery planning.
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Scan
Region Abdomen (Venous phase)
Scan length 300 mm
Slice collimation 4 x1 mm
Table feed/rotation 6 mm
Pitch 6
Scan direction craniocaudal
Rotation time 0.5 s
kV 120
mAs 130
Kernel B20
Scan time 25.9 s
Contrast Injection
Volume 120 ml (non-ionic contrast medium)
Concentration 300 mg iodine/ml
Flow rate 3.5 ml/s
Start delay 70 s
Image reconstruction
Reconstructed slice width 1.25 mm
Reconstruction increment 0.8 mm
Postprocessing
Multiplanar reformations +
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Fig. 1: Patient with bilateral renal angiomyolipoma.
Coronal reformatted image shows huge multiple
bilateral renal masses.The kidneys are all displaced.
The lesions contain low-density areas consistentwith fat.
Fig. 2: Coronal reformatted image generated from
the axial data set.There is extensive involvement of
perinephric space by the bilateral angiomyolipomas.
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History:A 58-year-old male with history of smoking with swallow-
ing disorder of three months.
Technical data:Spiral scanning with a multislice spiral CT scanner
(SOMATOM Volume Zoom, Siemens, Forchheim, Germany),
and multiplanar reformations (MPR).
Results and comments:This case illustrates the advantages of multislice spiral CT.
It affords the ability to simultaneously evaluate the soft
tissue mass and the surrounding structures (Fig. 1). The
increasing pitch and subsecond scan time allowed cover-
age of the entire cervical region in one spiral. This shorter
examination time reduces the number of motion artifacts
and represents an advantage for patients who are not able
to cooperate. The kernels used ensure a high quality softtissue detail.
In this case, one could argue that multiplanar reformatted
images are actually more critical than the axial images
themselves. Coronal and sagittal reformatted image of axial
sections can be useful to evaluate the extent of different
lesions (Fig. 2). In special cases concerning the laryngeal
skeleton, high resolution CT with a slice width of 1 mm is
possible.
Supraglottic and Glottic Larynx Cancer
Scan
Region Hyoid to subglottic space
Scan length 160 mm
Slice collimation 4 x 1 mm
Table feed/rotation 4 mm
Pitch 4
Scan direction craniocaudal
Rotation time 0.5 s
kV 120
mAs 110
Kernel B30
Scan time 21.56 s
Image reconstruction
Reconstructed slice width 1.25 mm
Reconstruction increment 1.0 mm
Postprocessing
Multiplanar reformations +
Contrast Injection
Volume 80 ml (non-ionic
contrast medium)
Concentration 300 mg iodine/ml
Flow rate 3 ml/s
Start delay 40 s
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Fig. 1: Patient with right-sided supraglottic and glottic
carcinoma. Axial image demonstrates clearly soft
tissue detail, the infiltration of the pre-epiglottic fat and
the adjacent structures.
Fig. 2: The sagittal reformatted image displays the
extent of the tumor.Step artifacts are negligible due to
the thin collimation used to acquire the original axial
images.The extensive tumor spread cranially is well
documented.
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History:57-year-old male patient with progressive swallowing
disorder. History of nicotine and alcohol abuse.
Clinical examination raises suspicion of a tonsillar carcinoma
with infiltration of the tongue and enlarged right sided
cervical lymph nodes.
Technical data:
Results:The depth of the tumor infiltration is best visualised with
a combination of axial and reformated coronal and sagittal
images. MPR images minimize partial volume effects
and allow better tumor delineation. Critical areas like the
parapharyngeal, paralaryngeal, preepiglottic and preverte-
bral space can be visualised in their full extension.
Infiltration of the base of the skull with bone destruction
can be diagnosed without additional coronal scanning.Criteria for lymph node malignancy, known from ultra-
sound, like the L/T quotient (ratio of maximal longitudinal
to maximal axial diameter) are more practicable. This leads
to more accurate staging, and pathology can be better
demonstrated to the clinical partner, allowing easier imagi-
nation of the situs than with axial images.
Squamous Cell Carcinoma of the Oropharynx
Fig. 1: Tumor infiltrating right floor of the mouth, base
of the tongue and tonsillar space.Typical rim enhance-
ment of ipsilateral lymph node metastasis.
Calcified plaque dorsally in the left carotid bifurcation
leading to an asymptomatic internal carotid artery
stenosis.
Scan
Region base of skull to aortic arch
Scan length 260 mm
Slice collimation 4 x 1 mm
Table feed/rotation 6 mm
Pitch 6
Scan direction craniocaudal
Rotation time 0.5 s
kV 120
mAs 165
Kernel B30
Scan time 22.4 s
Image reconstruction
Reconstructed slice width 4 mm/1.25 mm
Reconstruction increment 2 mm/1 mm
Postprocessing
Multiplanar reformations +
Contrast Injection
Volume 150 ml (non-ionic
contrast medium)
Concentration 300 mg iodine/ml
Flow rate 2.5 ml/s
Start delay 80 s
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Fig. 2: Central hypodensity indicating tumor necrosis.
Tumor spreads close to the mandible,but there is no
bony destruction. Parapharyngeal space is obliterated
by tumor. Small lymph nodes along the great vessels
on both sides with no signs of malignancy.
Fig. 4: Sagittal image demonstrates size of tumor in
relation to intrinsic muscles of the tongue, the floor of
the mouth and the valleculae epiglotticae as well as
the hard and soft palate. Good delineation of the spatium
retropharyngeum, the hypodense space between the
prevertebral fascia and the pharynx.
Fig. 5: Sagittal images allow accurate assessment
of lymph nodes. Lymph node metastases ventral
of internal jugular vain, lymph nodes without signs
of malignancy dorsal.
Fig. 3: Coronal image clearly demonstrates
craniocaudal tumor spread and relation to adjacent
structures like the submandibular glands.
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8/14/2019 Somatom Sessions 03
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mpressum
his Issues Authors
Ulrich Baum, MD
Institute of Diagnostic RadiologyUniversity of Erlangen-NurembergMaximiliansplatz 1, D-91054 ErlangenGermany
Micheal Lell, MD
Institute of Diagnostic RadiologyUniversity of Erlangen-NurembergMaximiliansplatz 1, D-91054 ErlangenGermany
Cheng Hong, MD, Roland Bruening, MD
Department of Diagnostic RadiologyKlinikum of theLudwig-Maximilians-UniversityMarchioninistr. 15, D-81377 Munich
Germany
Daniel A. Finelli, MD
Section of NeuroradiologyThe Cleveland Clinic Foundation9500 Euclid Avenue, Cleveland,Ohio 44195USA
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