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Clinical 3D Imaging Has Its Time Finally Arrived?
Case Reportson Volume Imaging
SOMATOMS E S S I O N S
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This is the eighth issue of Siemens SOMATOMSessions.
It provides insights from clinical 3D imaging together with
case reports from Siemens SOMATOM Volume Zoom users.
This issue focuses on the many improvements made
possible through volume imaging.
As always we would appreciate your suggestions and
comments.
Xiaoyan Chen, M.D.
Editor of SOMATOM Sessions
CONTENTS
FROM THE EDITOR
Letter from the Editor Page 2
Clinical 3D Imaging
Has Its Time Finally Arrived? Page 3
An arteriovenous malformation involving
the second and third digits of the left foot Page 10
MSCT diagnosis on conductive hearing loss Page 12
Pancreatic Carcinoma Page 14
Chronic Intestinal Ischemia:
Superior and Inferior Mesenteric Artery
Stenosis Depicted by Multislice CT Page 16
Axillary Deep Venous Thrombosis after
PORT-A-CATH Insertion Page 19
Multislice Spiral CT: Phlebography of the upper
extremity in a patient with shunt thrombosis Page 21
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
but not limited to the parameters selected during image acquisition and
postprocessing and any drugs and doses prescribed in connection with
such use.
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Three-dimensional imaging (3D) for CT applications was
introduced shortly after clinical CT scanning became a reality
in the late1970s. Whether through work done by Gabor
Herman and associates at the University of Pennsylvania or
Mike Vannier and associates at the Mallinckrodt Institute
of Radiology, 3D imaging was viewed as a way of extract-
ing more information from a series of transaxial CT scan
slices. Not surprisingly early applications involved bone espe-
cially in areas like the skull and craniofacial regions (regions
of high CT contrast and anatomic zones less affected by
patient motion or breathing). Although most radiologists
at the time were not enthusiastic about 3D reconstructions,
our referring physicians found them extremely helpful in
patient management decisions in complex cases. Over the
next15 or so years, 3D imaging continued to evolve with
the introduction of faster computer processing times, lower
priced workstations with better price/performance profiles,
and new rendering algorithms (i.e., volume rendering).
Yet, despite these and many other advances, 3D imagingcontinued to be a study performed in a select group of
institutions for a limited set of applications.
It is debatable why the progress of 3D imaging in the
radiologic environment was so slow but a number of reasons
have been suggested including:
High cost of workstations. Perceived notion that 3D had limited clinical applications.
3D was felt to be of value only to the referring physicianbut not to the radiologist.
Difficulty in using 3D workstations due to poor systemdesign and limited functionality.
A killer app (application) had not been developed todrive 3D imaging into the mainstream.
Major equipment vendors like Siemens Medical Systemsand GE did not push 3D as a mainstream product.
Poor reimbursement for 3D studies (especially thephysician component).
What really began to change the equation was the devel-
opment of spiral CT and the ability to obtain true volume
data sets which were ideal for 3D or volume imaging. With
the continued development of spiral CT scanning from a
technology where one could acquire 12 seconds of data to
a technology that could acquire up to 100 seconds of data,
things really began to change. New applications for CT
began to develop based on these new technologies and
capabilities. The role of 3D imaging was becoming more
of a core function of CT and inseparable especially with
applications like CT angiography and virtual endoscopy. The
introduction of multidetector CT and its advances for vas-
cular imaging continued this development cycle which has
been driving 3D imaging to become more of a standard
exam rather than a unique procedure. In fact, every scanner
manufacturer now recommends or ships a workstation
capable of 3D imaging with their high-end scanners (multi-
detector CT scanners (MDCT). Yet, there is still the feeling
among some radiologists that 3D imaging is not yet suitable
for their practice.This seeming contradiction may seem
hard to explain but is based in great part on the resistance
of radiology and radiologists to change.
In our experience, the biggest limitations to the use of
3D imaging (and otherpostprocessing tools) in the clinical
environment include:
A lack of understanding of the advantages provided bythese techniques both from a clinical and patient care
perspective.
A lack of understanding of how to use these newtechniques including a lack of understanding on how to
use the workstation.
A lack of understanding of how to merge new technolo-gies into a busy clinical practice that already may be
overwhelmed by the volume of work and/or a staffing
shortage (both radiologists and technologists).
Resistance to change especially changes in workdistribution and flow.
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These limitations can be translated into a need for:
Education Training Clarification of workflow issues Staffing
None of these problems however is insurmountable.
I believe that education can come from any of several
sources including:
CME courses including courses with hands-on sessions.For example, the RSNA as part of its annual meeting
has hands-on sessions on the use of computers including
medical workstations. Siemens Medical Systems has
sponsored a hands-on course using the 3DVirtuoso work-
station the past two years in Orlando and will have a third
meeting May 18-20, 2001, also in Orlando, Florida.
Reading the radiologic literature (and pertinent literaturefrom other subspecialties) and noting the clinical role of 3D
imaging especially as it applies to CT angiography.
Getting information from the vendor of your workstationincluding detailed hands-on training on the use of the work-
station and better system documentation. The Somatom
Sessions is an example of vendor supplied information that
is valuable for your daily clinical practice.
Web-based educational sites like www.CTISUS.comwhere all of the 3D protocols are available including a large
teaching file of illustrated 3D cases.
Training reflects more on the ability to obtain technical
expertise on a 3D imaging system. Although every work-
station vendor provides some form of hands-on training
it usually is but two-days duration and this may be unsatis-
factory for either the radiology technologist or radiologist.
It is not suprising that the most common complaint about
a workstation and its use is lack of sufficient training. This
problem can be solved by either the 3D vendors providing
enhanced training (including through web-based training)
on or off-site or for the interested parties to go to sites with
similar equipment and learn in a more hands-on method.
Unless there is improvement in the training available the
use of 3D imaging will continue to lag other technologies.
Progress has been made as for example Siemens Medical
Systems has begun to focus 3D training in a centralized
location in Cary, North Carolina, USA.
Workflow issues and staffing are both separate but closely
intertwined problems. The decision as to who does the
3D imaging (radiologist vs. technologist) and where the
workstation is located are decisions that are made by indi-
vidual institutions. Although my experience is one where
the radiologists do the actual 3D imaging (including creat-
ing the images and filming them), other sites have found
a dedicated technologist (with radiologist supervision) to
be an ideal strategy. The advantages of the radiologist only
works in cases where the radiologist(s) is dedicated to
committing the necessary time and effort to the enterprise.
This is becoming more of an issue where most institutions
are understaffed and trying to cope with the clinical load
without adding new studies. However, this is shortsighted
as using a technique like CT angiography will decrease the
staffing (both radiologist and technologist) needed for more
invasive procedures like classic angiography. In addition,
our view that the future of imaging revolves around direct
3D viewing replacing axial CT scanned based imaging,
which will require primary radiologist participation. One
factor that will increase the radiologists willingness to be
the primary person for the 3D-image analysis is the avail-
ability of true real-time volume rendering. The Siemens
3DVirtuoso with the VolumePro upgrade will make this
wish a reality.The real-time rendering of this system allows
the radiologist to analyze even the most complicated cases
in a matter of minutes.
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Other sites have found that a dedicated technologist can
perform most of the routine studies and the radiologist
works in a more supervisory role as well as doing the more
difficult/complex cases. Advantages of this workflow relate
to less of a commitment of the radiologists time and may
provide more continuity especially in those groups where
a radiologist is not based at any one hospital or office. In
this model selection of the technologist is critical as they
should be an individual who is willing to learn what the pur-
pose of each study is and is committed to continuing edu-
cation. The person must be self-motivated and committed
to the project. The technologist will also need people-skills
to deal with both the radiologist and the referring physician.
This workflow issue is critical to the success of any 3D
program and will need to be decided on a case to case basis.
Although it would be ideal to have multiple workstations
connected over a high-speed network capable of doing 3D
imaging this is rarely the case today.The decision as to
where to physically place the workstation is therefore
critical. I have found that it is ideal to have the workstation
away from the scanner suite in a separate room or office.
This allows consultation with referring physicians without
interrupting the primary function of the CT scanner which
is to scan patients.
This separate 3D suite or lab allows for the centralization
of function especially when a number of different scanners
and/or modalities are networked to a single workstation.
For example, at Hopkins our 3D lab is connected by a
100 megabyte backbone to scanners in the hospital, the
adjacent outpatient center, the adjacent oncology center,
the emergency room and a remote site 10 miles away.
All images seamlessly reach the workstation for postpro-
cessing. However, with our 3D volumes increasing to over
10 cases per day as well as the need for rapid image turn-
around (minutes rather than days), the location of the
workstation will soon have to be closer to the scanners and
reading room.
Workflow issues are obviously a critical factor in the
success of a 3D operation. The timely performance of a
CT scan will be negated if there is a time lag until the 3D
images are generated. Although many 3D studies do not
require an immediate turnaround, other applications are
very time-sensitive.These applications include acetabular
fracture repair (in select cases), suspected mesenteric
ischemia, and suspected aortic dissection.Training of enough
staff members to cover these off-hours cases is needed
to provide the 24/7 coverage demanded today. The use of
3D imaging in the acute setting is rapidly increasing.
Another problem with placing a workstation in a single
central location as 3D visualization becomes a primary
interpretation tool is that it would need to be located in the
scanner suite or in the area where films are interpreted.
This would potentially require a number of workstations
which would be cost-effective if used to enhance the
primary interpretation. Implementation of this paradigm is
beginning especially with the new design of the 3DVirtuoso
and its increased capabilities as a primary display and
analysis center.
Multidetector CT is probably the final brick that will push
3D imaging into the mainstream. Although I will not dis-
cuss the specific clinical advantages of MDCT, it is easy to
conclude that any 3D application that could be done pre-
viously can be done better due to a combination of factors
including narrower collimation, higher resolution imaging
and faster scan times.
MDCT also has resulted in many new applications for
CT now becoming a clinical reality. These include topics like
mesenteric angiography for ischemia, coronary artery
angiography and peripheral CT angiography. However, even
more than that is the practical reality of MDCT. While in
the prespiral era, a scan sequence of 35-50 images were
the rule, with multidetector spiral CT a typical study may be
anywhere from 150-600 slices.
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Even if film cost and storage were not an issue, the radio-
logist may become fatigued from looking at so many
images. 3D imaging or volume imaging may prove to be an
alternative. Viewing the entire data set as a volume with
an interactive 3D real time display may be ideal. The ability
to interactively segment out organs or organ systems will
help with more accurate detection of disease as well as
quantification of disease volumes. The use of an interactive
mode will also speed up the viewing process forboth the
radiologist and the referring physician. Another practical
factor is that studies like CT angiography cannot be truly
evaluated as axial images.The CT display must be more
like a classic angiogram and display the vessels in the for-
mat that show the vessels in a true vascular map. Volume
rendering is ideal for this task and provides breath-taking
images using the 3DVirtuoso.
6
Fig. 1: Pancreatic cancer with vessel displacement:
3D CT angiograms demonstrate displacement of both
the gastroduodenal artery and the celiac axis.
ba
Although a detailed analysis of specific 3D applications is
beyond the scope of the article, a brief listing of the direction
we are going will give you the feel of how 3D imaging will
become not only mainstream but a central part of imaging
in the 21st century. Although classic 3D imaging tended
to focus on orthopedic imaging like acetabular fractures or
tibial plateau fractures the hottest areas of interest focus
on vascular imaging. The applications include:
Oncologic imaging 3D mapping of tumors for betterstaging of disease as well as for surgical planning. Specific
applications include staging pancreatic cancer (figure 1),
renal cell carcinoma (figure 2), primary liver tumors as well
as lung cancer.
This is shown both with volume rendering technique
(a) and MIP (b) techniques.
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Fig. 2: Renal cell carcinoma:
CT angiography is used to determine eligible candi-
ba
Fig. 3: Mesenteric ischemia: (a-b)
This CT angiogram demonstrates occlusion of the
SMA and IMA and collateralization through the celiac
ba
dates for a partial nephrectomy. The patients right
renal cell carcinoma was successfully resected.
axis and gastroduodenal artery through the artery of
Drummond.
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Fig. 4: Renal donor:
This dual phase CT angiogram provides definition of
both the potential donors renal artery(s) (a) as well as
the venous anatomy (b).
ba
This study is used as the guide for laparoscopic
nephrectomy. Note the two left renal arteries.
Vascular imaging in addition to the evaluation of aorticaneurysms and dissection we are now doing CT angio-
grams for mesenteric ischemia (figure 3) and to look at
bowel activity in Crohns disease. Evaluation of carotid or
renal artery stenosis are two other strong applications.
CT is at least 40% cheaper than a conventional angiogram.
Organ donor imaging 3D CT angiography is the goldstandard for the preoperative evaluation of potential renal
donors (figure 4). It is also our study of choice for evaluat-
ing patients who are potential living related organ donors
or transplant recipients.
ConclusionThe modification of an established workflow pattern is
difficult and at times will seem impossible. This is especially
true if the old system worked well and its members are
satisfied with its performance. To paraphrase an old saying
everyone wants progress but no one wants change. It
is only when the system becomes unworkable orunsatis-
factory that the window for change opens.The introductionof MDCT and the new real-time capabilities and functio-
nality of the 3DVirtuoso will provide the impetus by creating
an environment where a new paradigm will be needed.
We look forward to these changes and the potential inno-
vative solutions that will be its result.
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Table 1The factors, which are driving 3D imaging into the realm
of a commonly used and accepted clinical study (by the
radiologic community) include:
A better understanding of the clinical value addedby 3D imaging.
The growth of CT angiography and the demand forclinical studies by the referring physicians.
Better reimbursements for 3D. Wealth of supporting data in the radiologic literature. Easier to use 3D workstations.
Table 23D CT Imaging: WorkFlow Issues.
Where Should the 3D Image Processing be Done?
A dedicated 3D lab. Anywhere there is space to put a workstation. In the CT reading area. In the referring physicians office, clinic and/or the O.R. Near the CT scanner.
Table 3The biggest limitations to the use of 3D imaging and other
post-processing tools are:
A lack of understanding of the advantages providedby these techniques.
A lack of understanding of how to use these newtechniques.
A lack of understanding of how to merge new techno-logies into a busy clinical practice that already may be
overwhelmed by the volume of work and/or a staffing
shortage (both radiologists and technologists).
References
www.CTISUS.com contains all the CT protocols for single
and multidetector CT as well as complete references for
all of the clinical applications. A lecture series on volumetric
3D imaging and Siemens MDCT is also available on the
site.
Elliot K. Fishman, M.D.
Professor of Radiology and Oncology
Johns Hopkins University School of Medicine
Baltimore, Maryland
U.S.A.
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An arteriovenous malformation involving theecond and third digits of the left foot
History55-year-old female patient with painful swelling of the
left lower foot. A CT angiogram was performed to assess
fora vascular malformation.
Technical Data
ResultsComputed tomography confirms the presence of an arterio-
venous malformation involving the second and third digits of
the left foot. Digital subtraction arteriography demonstrated
two major feeders from the dorsalis pedis artery as well
as multiple smaller feeders from the posterior tibial artery.
The CT angiogram demonstrates the complex arteriovenous
malformation with tremendous clarity when compared to
digital subtraction arteriography.The CTangiogram is limitedby the simultaneous visualization of the feeding arteries
and draining veins, however there is less staining of the nidus
of the AVM.Volume rendered views facilitate appreciation
of the three-dimensional relationships of this complex lesion
and were useful in planning embolotherapy.
CommentsMultislice spiral CT combined with 0.5 second gantry
rotation allowed imaging of the arterial supply of the left
leg from the knee through the toes with near isotropic
spatial resolution.As a result, small arteries and veins can
be visualized that were previously not identifiable by CT
scanning.
Maximum intensity projections provide a similar appearance
to that of the digital subtraction angiogram, while volume
rendering facilitates appreciation of three dimensional
relationships.
ScanRegion Foot
Scan length 480 mm
Slice collimation 4 x 1.0 mm
Table Feed/rotation 6 mm
Pitch 6
Scan direction craniocaudal
Rotation time 0.5 s
kV 140
mAs 120
Kernel uncertainScan time 40 s
Image Reconstruction
Reconstruction slice width 1.25 mm
Reconstruction increment 0.5 mm
Postprocessing
Maximum intensity projections and volume rendering
Geoffrey D. Rubin, M.D.
Associate Professor, Radiology
Stanford University School of Medicine,
Stanford, California, USA
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Fig. 1: AP and lateral maximum intensity projections
with an inverted gray scale demonstrate the entire
scan volume.The popliteal artery and the branches of
its trifurcation are demonstrated to enhance intensely
in the lateral aspect of the upper leg while early filling
of the saphenous venous system is observed medially.
Fig. 2: Detailed view comparing DSA and MIP-CTA
views of the forefoot. The AVM nidus is clearly seen on
the DSA examination involving the second and third
digits. Although the nidus is not opacified to the same
level on the CTA, its position is inferred by the manysmall vessels observed over the entire second digit in
the region of the metatarsal head as well as over the
medial aspect of the third digit.The DSA view is a com-
pilation of two views acquired five seconds apart show-
ing during the arterial and venous phases of the study.
The two views were added together to create a view
that is comparable to the CT, showing both arterial and
venous anatomy.
Fig. 3: Left and right lateral and AP volume renderings
of the forefoot demonstrate the three dimensional
relationships of this complex AVM. Vessels with grea-
test enhancement are encoded in white, followed
by intermediately enhancing vessels in red and less
enhancing vessels encoded in magenta.
3a 3b
3c
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Fig. 1: Axial image Fig. 2: MPR image
Fig. 3: VRT image Fig. 4: VRT image
Fig. 5: VRT image
Fig. 1-4: Ossicular interruption.
VRT images were generated from MPR images.
Fig. 5-6: Normal anatomical structure of the inner ear.
Fig. 6: VRT image
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Pancreatic Carcinoma
History65-year-old female patient with painless jaundice and
back pain for ten days. Ultrasound revealed stones in the
gallbladder, an extra- and beginning intrahepatic cholestasis
and an enlarged head of the pancreas with suspected
hypodense formation in the head of the pancreas. Lab works:
slightly incrased amylase and lipase, elevated phosphatase
and bilirubin and CA 19-9.
ERCP: Filiform stenosis of the common bile duct in the head
of the pancreas indicates carcinoma of pancreatic head.
Dilated pancreatic duct.
Technical Data
Patient preparationOral contrast medium:
1000 ml iodinated oral contrast material 1 h prior to
the examination, 500 ml water 10 minutes prior to the
examination.
Right side position for 5 minutes before scanning;
Spasmolysant immediately before scanning;
Supine position during scanning.
ResultsT1 carcinoma of the pancreatic head (histologically con-
firmed). Dilated common bile duct, slightly dilated pancreatic
duct. Small circular hyperdensity in the head of pancreas
surrounded by a small hypodense mass, which can not be
delineated from the portal vein and the superior mesenteric
vein on tansverse images. Coronal and sagittal MIP and
MPR confirm that the circular hyperdensity is the enhancing
wall of the bile duct, surrounded by a small hypodense
T1-tumor. Sagittal plane demonstrates the encasement of
the portal vein of less than one quarter of the circumference.
Therefore according to the criteria published by Lu et al.
1997 infiltration of the portal vein can be excluded. These
findings (T1 stage; no infiltration of the peripancreatic
vessels) were confirmed intraoperatively.
ReferencesLu DSK, Reber HA, Krasny RM, Kadell BM, Sayre J (1997)
Local staging of pancreatic cancer: criteria forunresectability
of major vessels as revealed by pancreatic-phase,
thin-section helical CT. AJR 1997; 168:1439-1443.
Scan
Region upper abdomen
Scan length 156 mm
Slice collimation 4 x 1 mmTable feed / rotation 4 mm
Pitch 4
Scan direction caudocranial
Rotation time 0.5 s
kV 120
mAs 165
Kernel B30
Scan time 23 s
Contrast Injection
Volume 120 ml (non-ionic contrast medium)
Concentration 370 mg iodine/ml
Flow rate 4 ml/s
Start delay 35 s
Image Reconstruction
Reconstructed slice width 1.25 mm/3 mm
Reconstruction increment 1 mm/3 mm
Postprocessing
Multiplanar reformations +
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Fig. 1: Axial image
This image shows a hypodense tumor in the head
of the pancreas, the enhancing common bile duct, the
slightly dilated pancreatic duct and the encasement of
the superior mesenteric vein for less than one quarter
of the circumference.
Fig. 2: Coronal MIP-reconstruction
This image shows normal calibre of the superior
mesenteric vein and the portal vein, the dilatation and
the enhancing wall of the common bile duct.
Pay attention to the small line of fatty tissue between
the portal vein and the carcinoma.
No suspicion of vascular infiltration on coronal MIPs.
Fig. 3: Sagittal MPR
This image shows the tumor in the pancreatic head
and the encasement of the portal vein for less than one
quarter of the circumference. Slight irregularity of the
lumen of the portal vein.
Ulrich Baum, MD
Institute of Diagnostic Radiology
University of Erlangen-Nuremberg
Maximiliansplatz 1
D-91054 Erlangen
Tel. ++49/9131/8 53-6066
Fax ++49/9131/853-6068
e-mail: [email protected]
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Chronic Intestinal Ischemia: Superior and InferiorMesenteric Artery Stenosis Depicted by Multislice CT
HistoryA 64-year-old woman has complained of chronic perium-
bilical pain for six months. The pain appeared half an hour
after each meal. She had a history of hypertension, heavy
smoking and right carotid bifurcation surgery. The pain was
also diffusing to her back. She lost 10 kg in 6 months. No
abnormality was detected by the sonography of the upper
abdomen, gastroscopy and coloscopy and the biology.
A multislice CT of the abdomen was performed to rule outvascular mesenteric lesions.
Technical DataThe spiral CT was acquired with a multislice spiral CT
(SOMATOM Volume Zoom, Siemens Medical Engineering,
Forchheim, Germany).
The following scan parameters were used:
Clinical comments and summaryThe angiographic criteria of a chronic mesenteric ischemia
consist in the presence of significant stenosis or obliteration
of 2 of the 3 main gastrointestinal arteries. For this patient,
the only large and safe artery of the intestine is the celiac
trunk. This case illustrates the ability of the Volume Zoom
to provide a precise vascular mapping and detect the arterial
lesions in the intestinal arteries. The 3D reconstructions
obtained with the Volume Wizard (MIP, MPR, SSD) superblydemonstrate the collateral vascular supply. Since the effi-
cacy of CT in the diagnosis of acute intestinal ischemia has
been demonstrated in comparison to angiography, further
studies will have to determine its performance and role in
the diagnosis of chronic intestinal ischemia for which angio-
graphy is still the imaging modality of choice.
References[1] Klein, H. M., Lensing, R., Klosterhalfen, B., Tons, C.,
Gunther, R.W.: Diagnostic imaging of mesenteric infarc-
tion. Radiology 1995 Oct; 197(1):79-82
[2] Yamada, K.,Saeki, M., Yamaguchi, T., Taira, M., Ohyama,Y.,
Ashida, H., Sakuyama, K., Ishikawa, T.: Acute mesenteric
ischemia. CT and plain radiographic analysis of 26 cases.
Eur Radiol 1999;9(7):1267-76
[3] Boley, S. J., Brandt, L. J., Veit, F. J.: Ischemic disorders
of the intestine. Curr Prob Surg, 1978, 15: 1-85.
[4] Rogers, A. L., Cohen,J.L.: Ischemic bowel disease.
Gastroenterology, 4ed.,vol.3, Editor: J. E. Berk. Philadelphia,
Saunders, 1915-1935.
KV 120mAs 90
Slice collimation 4 x 1 mm
Slice thickness 1.5 mm
FOV 37.9 cm
Recon increment 1 mm
Rotation time 0.5 s
Feed per rotation 8 mm
Total acquisition time 19.7 s
Reconstruction algorithm B20
Total number of images 313Injection protocol: brachial vein,
Nonionic contrast medium at
350 mg I/100 ml. Injection volume 100 ml
Injection rate 4 ml/s
Start delay 40 s
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Fig. 1: Maximum Intensity Projection (MIP, Fig. 1a)
and Volume Rendering Technique (VRT, Fig.1b) images
in a saggital oblique orientation demonstrating a
superior mesenteric artery stenosis.
Fig. 2: Left obliquely oriented coronal MIP (Fig. 2a)
and VRT (Fig. 2b) views showing collateral vascular
supply to the superior and inferior mesenteric arteries
originating from the celiac trunk and its branches.
1a 2a
2b1b
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Fig. 3: Obliquely oriented axial multiplanar reconstruc-
tion (MPR) at the level of the origin of the superior
mesenteric artery. A luminal interruption is observed
with an intramural blood clot (white arrow).
Fig. 4: Saggital oblique MPR showing a stenosis at the
origin of the inferior mesenteric artery (white arrow).
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Chronic Intestinal Ischemia: Superior and InferiorMesenteric Artery Stenosis Depicted by Multislice CT
Denis Tack, M. D.
Department of Radiology C.H.U. de Charleroi
Boulevard Janson 92
B-6000 CHARLEROI/BELGIUM
Phone: (32 71) 25 1525
Fax: (32 71) 25 17 09
E-mail: [email protected]
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Axillary Deep Venous Thrombosis afterPORT-A-CATHInsertion
HistoryA 53-year-old woman complained of swelling of the left
arm for 24 hours. One week before, a Port-A-Cath
device had been inserted in her left jugular vein. She was
treated with chemotherapy for a gastric carcinoma.
Technical DataThe spiral CT was acquired with a multislice spiral CT
(SOMATOM Volume Zoom, Siemens Medical Engineering,
Forchheim, Germany).
The following scan parameters were used:
Clinical comments and summaryCentral venous access devices are often essential for the
administration of chemotherapy to patients with malignancy,
but its use has been associated with a number of compli-
cations, mainly thrombosis (1). Its sequelae include septic
thrombophlebitis, loss of central venous access and pulmo-
nary embolism. Phlebography is the imaging modality of
choice to demonstrate the venous thrombosis. However,
it is not appropriate to delineate precisely innominatal veincompressions that occur in the antero-posterior direction
as lymphadenopathies do in the anterior uppermediastinum
(Figure 1).This case shows the ability of multislice CT to
depict the venous thrombosis and its causes, the insertion
of a catheter in a compressed left innominatal vein.The
MIP images obtained with the Volume Wizard perfectly
demonstrate the collateral vascular supply to the chest
wall and obviate the need for venography. Essential to the
technique is the injection of an iodine contrast of low
concentration in both forearms.This allows opacification ofthe bilateral thoracic veins simultaneously. The dilution is
essential to avoid artifacts in the superior vena cava. Some
authors recommend a preventive treatment of venous
thrombosis related to Port-A-Cath device with a low mole-
cular weight heparin (2).
References[1] Lersch, C., Eckel, F., Sader, R., Paschalidis, M.,
Zeilhofer, F., Schulte-Frohlinde, E., Theiss,W.:
Initial experience with Healthport miniMax and other peri-
pheral arm ports in patients with advanced gastrointestinal
malignancy. Oncology 1999; 57(4):269-75
[2] Monreal, M., Alastrue, A., Rull, M., Mira, X., Muxart, J.
Rosell, R., Abad,A.: Upper extremity deep venous
thrombosis in cancer patients with venous access devices
prophylaxis with a low molecular weight heparin
(Fragmin). Thromb Haemost 1996;75(2):251-3.
Region of interest: from the diaphragm to the
hyoid bone
Acquisition direction caudo-cranial
KV 120
mAs 77
Slice collimation 4 x 1 mmSlice thickness 1.5 mm
FOV 36.7 cm
Recon increment 1 mm
Rotation time 0.5 s
Feed per rotation 8 mm
Total acquisition time 17 s
Reconstruction algorithm B20
Total number of images 229
Injection protocol: Nonionic contrast medium
at 350 mg I/100 ml
Dilution of the contrast 1/4
Injection volume
in the left arm 50 ml at a rate of 2 ml/s
Injection volume
in the right arm 150 ml at a rate of 4 ml/s
Start delay 20 s
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Fig. 3, 4: Maximum intensity projection with 10 cm
thickness (Fig.4) and VRT (Fig. 3) images demonstrating
the normal right thoracic veins, the position of the
PORT-A-CATH device and the venous collaterals from
the left axillary region to the intercostal and mid vertical
thoracic vein.
Fig. 1, 2: Coronal MPR (Fig. 1) and VRT (Fig. 2)
at the level of the left jugular vein and the catheter.
Mediastinal and cervical bilateral lymphadenopathies,
and left axillary vein thrombosis.
3
1 2
4
Axillary Deep Venous Thrombosis afterPORT-A-CATHInsertion
Denis Tack, M. D.
Department of Radiology C.H.U. de Charleroi
Boulevard Janson 92, B-6000 CHARLEROI/BELGIUM
Phone: (3271) 251525, Fax: (3271) 25 17 09
E-mail: [email protected]
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Multislice Spiral CT: Phlebography of thepper extremity in a patient with shunt thrombosis
HistoryA 38-year-old patient with end stage renal disease presented
with massive swelling of the right forearm and a history
of repeated shunt thrombosis. Physical examination on
admission revealed normal perfusion of the dialysis shunt
on the right upper arm.
Spiral CT was performed on suspicion of central thrombosis
and to exclude mediastinal mass.
Technical DataScanner: SOMATOM Volume Zoom, Siemens, Germany
DiagnosisAcute central thrombosis of the right subclavian vein is
evident, without apparent anatomical reason (mass or
muscular hypertrophy). On the left side thrombosis of the
subclavian and axillary vein due to ipsilateral shunt throm-
bosis is shown. Multiple varicoid bypasses drain the left
upper extremity. Extensive opacification in vessels with
reduced blood flow is seen on the left arm because of cen-
tral vein thrombosis, whereas lower opacification is seenin the shunt on the right side due to high, arterialized blood
flow. A filiform stenosis of the right brachiocephalic vein is
demonstrated proximal to the confluence of the superior
cava vein.
CommentsWith MSCT an isotropic volume data set can be acquired
in a single breathold. Out of this data set, views from arbitrary
chosen directions can be processed. Only little contrast
material (50 ml) was needed to achieve sufficient contrast
enhancement of both brachiocephalic veins due to the
short acquisition time. The administration of contrast mate-
rial is a central issue for the assessment of vessels.Amount
and concentration of contrast material, flow rate and start
delay are important parameters for homogenous opacifi-
cation without inflow- or high contrast artifacts. In this
patient, the delay between the start of contrast material
injection and the spiral scan was chosen empirically.To
have visual control of optimal opacification, semiautomatic
bolus triggering techniques can be used to optimize the
start delay. With such techniques a further reduction of con-
trast material volume is possible at the expense of a slight
increase of radiation dose. Dilution of the contrast material
is necessary to avoid high contrast artifacts. Both luminal
and extraluminal pathology (i.e. tumor mass, anatomical
variants) can be assessed and information of both venous
and arterial vessels is provided. Details of thrombus mor-
phology are availible and exact planning of an interventional
procedure is possible.
Slice collimation 4 x 1 mm
Table feet 8 mm/s
Rotation time 0.5 s
Reconstructed slice width 1.25 mm
Reconstruction increment 1 mm
Total scan time 22 s
Thin slice MIP +
Contrast material Optiray 300, Schering, Germany
Total volume 50 ml, diluted with 50 ml NaCl 0.9%
Injection rate 2.0 ml/s
Start delay 50 s
Injection was performed in the left antebrachial vein and
the shunt on the right arm simultaneously with a power
injector.
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Multislice Spiral CT: Phlebography of theupper extremity in a patient with shunt thrombosis
In addition to the axial images, 3D postprocessing can help
visualize pathology within one image and in orientations
used from DSA.Thin slice MIP is an easy and quick method
to display the vascular anatomy without time consuming
editing procedures. Cross sectional images help to differen-
tiate adherent from floating thrombus and measurements
of the diameter of the vessel help choosing the correct
dimension of angioplasty catheter and stent.
The patient was treated interventionally with dilatation and
stent implantation.
Michael Lell, M.D.
Institute of Diagnostic Radiology
University of Erlangen-Nuremberg
Erlangen, GermanyFig. 1a-d: Axial images show the central thrombosis
of the right subclavian vein.
Fig. 2: Axial MPR image shows the thrombosis of the left
subclavian vein.Fig. 3: Oblique axial MPR image shows the thrombosis
of both right and left subclavian veins.
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4 5
Fig: 4, 5: MIP images show different views of the filiform
stenosis of the right brachiocephalic vein proximal to the
confluence of the superior cava vein.
Fig: 6,7: MPR (Fig.6) and MIP (Fig. 7) images show the
thrombosis of the left subclavian and axillary vein due to
ipsilateral shunt.
6 7
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MPRESSUMPublished by
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THIS ISSUES AUTHORSClinical 3D Imaging Has Its Time Finally Arrived?
Elliot K. Fishman, M.D.
Professor of Radiology and OncologyJohns Hopkins University School ofMedicine, Baltimore, Maryland, USA
An arteriovenous malformationinvolving the second and third digits ofthe left foot
Geoffrey D. Rubin, M.D.
Associate Professor,RadiologyStanford University Schoolof Medicine, Stanford, California, USA
MSCT diagnosis on conductivehearing loss
Anders Persson, M.D.
Head of Radiology ClinicThe Hospital of Hlsingland SderhamnSweden
Pancreatic Carcinoma
Ulrich Baum, M.D.
Institute of Diagnostic RadiologyUniversity of Erlangen-NurembergErlangen, Germany
Chronic Intestinal Ischemia: Superiorand InferiorMesenteric Artery StenosisDepicted by Multislice CT
Denis Tack, M.D.
Department of RadiologyC.H.U. de CharleroiCHARLEROI, BELGIUM
Axillary Deep Venous Thrombosis afterPORT-A-CATHInsertion
Denis Tack, M.D
Department of RadiologyC.H.U. de CharleroiCHARLEROI, BELGIUM
Multislice Spiral CT: Phlebographyof the upper extremity in a patient withshunt thrombosis
Michael Lell, M.D.
Institute of Diagnostic RadiologyUniversity of Erlangen-NurembergErlangen, Germany