Chapter 105: Gastrointestinal Imaging

(A–C) Consecutive axial computed tomography (CT) scans show voluminous ascites (A) in a postoperative transplant recipient. Notice the residual pneumoperitoneum and gas at the abdominal wall scar (arrows).

(A–B) Posttransplantation ascites: axial CT scans show ascitic fluid completely surrounding the liver (A). Notice that peritoneal fluid extends posterior to segment 7 (yellow arrows) because there is no longer a bare area due to the detachment of the coronary and triangular ligaments. Of note is the presence of a small pocket of residual gas after surgery (red arrow).

(A) Longitudinal gray-scale ultrasound shows multiloculated fluid collection. Notice numerous septa (arrows). (B) Corresponding CT scan clearly demonstrates the fluid collection indenting on the liver contour (FL). Periportal low attenuation is due to periportal edema.

Fluid collection with gas bubbles. CT scan shows extensive fluid collection with multiple gas pockets (yellow arrows) located intraperitoneally and extending from the anterior prehepatic space to the left upper quadrant surrounding the spleen. Of note is the presence of an infarction in the spleen (red arrows).

(A) Longitudinal ultrasound shows a biconvex echogenic fluid collection (demarcated by crosses). The internal echoes suggest a particulate composition of the collections, in this case, due to hemorrhagic content. (B) Axial unenhanced CT reveals high-attenuation appearance typical of hematomas in this elongated perihepatic collection (arrows).

(A–B) Axial contrast-enhanced CT scan shows central low-attenuation thrombus in superior mesenteric vein (SMV) lumen (yellow arrow) with increased enhancement of vessel wall. Notice jejunal wall thickening (red arrows), as well as mesenteric haziness due to edema (asterisk). Ascitic fluid (A) is also noted.

(A–B) Axial CT scans show marked colonic and rectal wall thickening with “target sign” (arrows). Notice the so-called “accordion sign” characteristic of pseudomembranous colitis (red arrow). Moderate ascites is seen adjacent to the colon. Notice umbilical recanalized collateral varices (short arrow).

CT scan shows diffuse thickening of the colonic wall (yellow arrows). The appearance is consistent with colitis. Cytomegalovirus colitis was confirmed ...