There is a small bowel obstruction, but there are also findings of ischemic/infarcted bowel with contained perforation. On the image below, you can see discontinuity in the bowel wall as it transitions from enhancing to non-enhancing wall (yellow arrows) with abnormal wall and perforation in between. Normally enhancing bowel wall is seen opposite (red arrow).
Similar findings are seen on the coronal images. On a representative image below, the yellow arrow marks the transition between enhancing and non-enhancing bowel wall. The red arrow denotes normally enhancing bowel wall.
Helpful tips
You should always have an internal comparison to determine if a loop of small bowel demonstrates hypo- or non-enhancement. Keep in mind that jejunum is thicker than ileum with more folds, so it will appear to have greater enhancement. The degree of wall enhancement also depends on distention. On the image below, you can see the difference in the appearance of enhancing bowel wall in distended (red arrow) and decompressed (green arrow) bowel wall.
The difference in appearance between distended and decompressed small bowel is also important when looking at CT enterography studies and determining if a loop of bowel has abnormally increased enhancement suggesting active inflammatory bowel disease. Decompressed bowel will look like it's hyperenhancing relative to distended bowel. Look for additional findings such as bowel wall thickening and edema (target sign).
Ischemic/infarcted bowel on CT is often subtle and easily missed, even when the indication is "concern for bowel ischemia". You have to make a concerted effort to look for hypo/non-enhancing bowel because the finding doesn't jump out. It's usually harder to see something that's missing (enhancement) compared to something that shouldn't be there (mass). Make use of the coronals for anything involving the bowel, especially bowel ischemia.
This patient was discharged after a few weeks of conservative management. He subsequently underwent surgery for recurrent abdominal pain and obstruction with pathology demonstrating densely fibrotic changes in the small bowel that was resected. This is not an unusual finding in patients with chronically ischemic/infarcted bowel, which can become fibrotic.
As a side note, my search pattern includes the entire SMA on every case. I have several cases of missed SMA thrombus in patients who came back a few days later with infarcted bowel. You do not want to miss SMA thrombus.
