07-1 Subclavian Artery Disease: Simulation Training Curriculum.
17 Case Subclavian
-
Upload
pan-jessica -
Category
Documents
-
view
217 -
download
0
Transcript of 17 Case Subclavian
7/29/2019 17 Case Subclavian
http://slidepdf.com/reader/full/17-case-subclavian 1/4
Case Study
Multislice CTDiagnosis of Subclavian Artery Stenosis
7/29/2019 17 Case Subclavian
http://slidepdf.com/reader/full/17-case-subclavian 2/4
Multislice CTDiagnosis of Subclavian Artery Stenosis
A 54-year-old female presents with
lightheadedness, syncope, and
slurred speech. The patient was
admitted for stroke vs transient
ischemic attacks.
Initial head CT without contrast was
negative for CVA or hemmorhage.
Bilateral carotid doppler study was
performed which revealed no hemo-
dynamically significant stenosis.
However, there was retrograde flow
in the left vertebral artery and ante-
grade flow in the right.
Chest CTA was performed to evaluate
the left subclavian artery for surgial
disease in a patient with subclavian
steal.
2 Case Study
Technical Data
Patient positioning Head first/supine, arms down
Scan range From below the aortic arch through the
carotid bifurcations
Scan mode ECG gated spiral CT
kV 120 kV
Effective mAs 425 mAs
Rotation time 0.5 s
Slice collimation 4 x 1 mm
Slice width 1.25 mm
Table feed/rotation 1.8 mm
Pitch 1.8
Scan direction Caudal-cranial
Reconstruction increment 1 mm
Kernel B20Retrospective ECG gating -400 ms
History
Contrast medium 370 Isovue
I.V. administration 20g i.v. in the right antecubital vein
Volume 150 cc
Flow rate 3 cc/s
Start delay 30 s
Post processing
[1] Multiple thin sliding maximum intensity projections (MIP) on the
Wizard: Sagittal and coronal, 10 mm thick with a reconstruction spacing
of 1.5 mm. The MIPs were angled to follow the course of the vesssel.[2] Volume rendering on the SOMATOM Volume Zoom.
[2] Coronal (A) andsagittal (B) MIP images
show the stenosis(arrowheads) proximal
to the origin of thevertebral artery in the
thyrocervical trunk
A B
7/29/2019 17 Case Subclavian
http://slidepdf.com/reader/full/17-case-subclavian 3/4
Results
It has been my experience when
performing CTA of the subclavian
artery that cardiac pulsations can
cause artifacts that can mimic
stenosis or thrombus. The subclavian
artery is seen very well but the actual
junction of the subclavian and aorta
(or carotid and aorta) can be blurred.
Comments
CT Angiogram of the left subclavian
artery revealed a high grade stenosis
just proximal to the origin of the
vertebral artery in the thyrocervical
trunk. This finding reflects the etio-
logy for the patient‘s subclavian steal
syndrome.
As another example shown in [4]
that the scan was also performed for
subclavian steal but the results were
inconclusive due to the cardiac pulsa-
tion artifact. On the AP projection
you can see what appears to be a
stenosis at the base of the Lt. sub-
clavian artery [4 A]. This is a false
positive finding. Subsequent conven-
tional arteriography demonstrated a
patent Lt. subclavian artery without
stenosis. The lateral projections show
the pulsations and it is very difficult
to diagnose any stenosis [4 B].
With HeartView CT, we can get a
motion free angio image of the aortic
arch and subclavian artery, which
clearly shows the area of stenosis.
There are no suspicious areas where
the radiologist would question:”Is that motion artifact or real patho-
logy?” Currently we are performing
this kind of study in our clinical
routine applications, and we are also
in the process of optimizing the dose
for such an application.
[3] Axial imageshows an area of stenosis (arrow) in
the medial aspect of the left subclavianartery
[1] VRT imagesconfirms stenosis(arrows)
[4] Coronal (A)and sagittal (B)
MIP images showcardiac pulsationartifacts makingthe diagnosis of
stenosis difficult
A B
7/29/2019 17 Case Subclavian
http://slidepdf.com/reader/full/17-case-subclavian 4/4
Order No. A91100-M2100-A535-1-7600
Printed in Germany
CC 63535 WS 03025.
Author:
Chris Deangelo RT (R), (CT)
Imaging Coordinator
CT Department
Alamance Regional Medical Center
Burlington, NC
USA
The information presented in this case report is for
illustration only and is not intended to be relied upon
by the reader for instruction as to the practice of
medicine. Any health care practitioner reading this
information is reminded that they must use their own
learning, training and expertise in dealing with their
individual patients. This material does not substitute
for that duty and is not intended by Siemens Medical
Solutions Inc., to be used for any purpose in that regard.
Note:
Original images always lose a certain amount of detail
when reproduced.
Siemens AG, Medical Solutions
Henkestr. 127, D-91052 Erlangen
GermanyTelephone: ++49 9131 84-0
Internet: SiemensMedical.com
Siemens AG, Medical Solutions
Computed Tomography
Siemensstr. 1, D-91301 ForchheimGermany
Telephone: ++49 9191 18-0