Vascular - Learning Modules - CTisus.com CT Scanning

Learning Modules ❯ Vascular

CT of the Aorta & Its Branches: Acute Processes

Elliot K. Fishman M.D.
Johns Hopkins Hospital

Click here to view this module as a video lecture.

CTA of the Vascular Map in the Abdomen: Advantages

Scan protocols are reproducible and less dependent on scanner and scan operator
Scan times are measured in seconds and patient cooperation minimized
Imaging of vessels and bowel and major organs in single acquisition
High spatial resolution for small vessels and pathology
Post processing critical in all cases
Ability to routinely detect pathology beyond the area of interest (major organs)
Availability in the ER setting 24/7/365

Crohn's Disease with Comb Sign and Fibrofatty Spread

Acute Abdomen with SMA Thrombus in Ischemic Bowel Evaluation

Fibromuscular Dysplasia (FMD) and Role of 3D Mapping

Clinical Presentation FUO and Hematuria

Diagnosis: PAN with Multiple Aneurysms in Kidney, Mesenteric Vessels

Clinical Presentation FUO and Hematuria

CTA in the Abdomen: Applications

Scan Parameters
- Fixed delay
- Bolus triggering
- Test bolus technique

3D CT Angiography Protocol:Arterial Phase (64MDCT)

CT Evaluation of the Small Bowel

Axial
MPR (usually coronal display)
3D Volume Rendering and MIP

Crohn's Disease (Active)

SMA Syndrome: Facts

Seen with

Marked weight loss
Anorexia nervosa
Total body casting

SMA Syndrome:Facts

SMA angle to aorta normally 45 degrees (range 38-56 degrees) while in SMA syndrome has SMA angle of 6-25 degrees
SMA to aorta distance normally 10-20 mm while in SMA syndrome is 2-8 mm

SMA Syndrome

Normal Artery Size

Celiac trunk, 0.79 ± 0.06 cm
Common hepatic artery, 0.50 ± 0.04 cm
Proper hepatic artery, 0.45 ± 0.03 cm
Splenic artery, 0.46 ± 0.03 cm

Intestinal Ischemia and Infarction - Etiology

arterial disease
- occlusion secondary to atherosclerosis
- occlusion secondary to emboli
- trauma
venous disease
- due to venous thrombosis
- portal hypertension
- estrogen use

Ischemic Bowel Disease: CT Findings

luminal dilatation

bowel wall thickening
dilated mesenteric veins
edema in mesenteric fat
intramural gas
mesenteric or portal venous gas

“ Ischemia is the complication that increases the morbidity and mortality associated with SBO. Specifically, the mortality rate in patients who undergo surgery for SBO with ischemic bowel is as high as 25% compared with those with SBO without strangulation, which may be as low as 2%. When ischemia is suspected, immediate surgery is required to avoid transmural necrosis and perforation.”
Review of Small-Bowel Obstruction: The Diagnosis and When to Worry
Paulson EK, Thompson WM
Radiology. 2015 May;275(2):332-42.

“Although surgery should be considered first in the presence of CT findings of bowel infarction, conservative management without anticoagulation therapy has good outcomes in the care of patients with no bowel ischemia, rupture risk or symptoms.”
Spontaneous Dissection of the Splanchnic Arteries: CT Findings, Treatment and Occlusion
Jung SC et al.
AJR 2013;200:219-225

“The CT findings associated with ischemic bowel include bowel with thickening, mesenteric edema and/or fluid in the adjacent mesentery or peritoneal space, abnormal decreased bowel wall enhancement, and pneumatosis with or without associated gas in mesenteric or portal veins .”
Review of Small-Bowel Obstruction: The Diagnosis and When to Worry
Paulson EK, Thompson WM
Radiology. 2015 May;275(2):332-42.

Atherosclerotic Disease of the Mesenteric Vessels

Plaque in SMA

SMA Occlusion