RADIOLOGY CLINICAL IMAGAGING AN ATLAS OF DIFFERENTIAL DAIGNOSIS EISENBERG

1. 64Attenuation Patterns in the
Abnormal Bowel Wall

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig GI 64-1 White attenuation in shock bowel. Increased
enhancement in the jejunum (black arrows). Note that the
attenuation is greater than that of the inferior vena cava
(curved arrow). The enhancement qualities could be
mistaken for oral contrast material in the lumen, but none
was given. (Straight white arrow = fluid in stomach.)81

4. • Fig GI 64-2 White attenuation in acute ulcerative colitis. Uniform
increased enhancement (straight black arrow) in the thickened wall
of the rectosigmoid. The attenuation of this segment of the colon is
similar to that of the external iliac vein (curved arrow). The
pericolonic vessels are dilated (white arrow).81

5. • Fig GI 64-3 Gray attenuation in ischemic colitis.
The attenuation of the enhancing walls of the
colon (solid straight arrows) falls short of that of
the superior mesenteric venous branch (curved
arrow) and inferior vena cava (open arrow).
Therefore, interpretation in this case should be
assigned to the gray attenuation pattern.81

6. • Fig GI 64-4 Gray attenuation in colon carcinoma.
The thickened wall of the mid-descending colon
(straight arrow) has an attenuation similar to that
of the adjacent muscle (curved arrow).81

7. • Fig GI 64-5 Water halo sign in bowel obstruction. Inner layer of a
strangulated, ischemic segment of small bowel (small straight solid
arrows) is surrounded by a lower attenuation layer (curved arrows). Note
the brightness of the dilated, obstructed proximal small bowel wall (open
arrow), which approximates the attenuation of the external iliac vein
(arrowhead). However, since the wall of the dilated bowel is not
thickened, it would not be considered abnormal (large straight arrow
indicates ascites).81

8. • Fig GI 64-6 Target sign in angioedema. Several segments of
small bowel demonstrate three uniformly thick layers. The
layers grossly correspond to the muscularis propria (straight
solid arrows), submucosa (curved arrow), and mucosa
(open arrow). Arrowhead indicates ascites.81

9. • Fig GI 64-7 Fat halo sign in ulcerative colitis. An outer
enhanced layer (straight solid arrows) surrounds a fat-
attenuation layer (curved arrows). Contrast material is
seen within the colonic lumen (open arrow).81

10. • Fig GI 64-8 Fat halo sign in chronic radiation enteritis. Several
segments of small bowel have walls thickened by a central band of
lower attenuation consistent with fat (arrowheads). The target
configuration is evident in one segment that lacks luminal oral
contrast material (solid arrow). Other segments with a fatty layer
have luminal contrast enhancement, which conceivably could be
obscuring a higher attenuation “mucosal” layer (open arrows).81

11. • Fig GI 64-9 Black attenuation in cecal pneumatosis. There
are rounded collections of mural gas attenuation (straight
solid arrows) in this patient with ischemic colitis. Mural gas
attenuation is also seen at the outer margin of the colonic
wall (curved arrows) and lumen (open arrow).81