Technique for 3 phase CT mesenteric angiography is very important.
1. patient must be bleeding at the time of the examination and should be scanned immediately if they start to bleed (as it can be intermittent)
2. no positive oral contrast as it will obscure detection of vascular extravasation
3. initial non-contrast imaging to detect pre-existing radio-opaque luminal structures (as in this case)
4. large volume IV contrast bolus and rapid imaging for maximal arterial opacification and detection of contrast leak (as in this case)
5. delayed post contrast imaging (I use 5 minutes) to confirm that that the apparent contrast leak is not contained within a vascular structure and is dispersing into the bowel lumen (as in this case)