Cool, thanks a bunch for that helpful info. My main goal is to get adequate imaging of the mesenteric vessels, celiac axis in a single pass CT to look for any lesions that can be treated in case the patient's cause of abdominal pain, rectal bleeding turns out to be mesenteric ischemia so I don't have to get a dedicated CTA. I'm not so much concerned about imaging for hypervascular polyp or obtaining imaging to locate source of bleeding, although, it would be great to see contrast extrav into the lumen to locate source, that to me is more extra information, not the primary goal, and I don't usually give oral contrast anyway. Most of these patients will get an EGD, colonoscopy, capsule to look for source; we don't rely on the CT as much but can't determine a proximal SMA, celiac axis stenosis or large embolic clot cutting circulation on endoscopy.
If there is no added radiation or contrast dose and I can get CTA quality imaging with a split dose bolus timed for mesenteric arterial phase and portal venous phase in a single pass CT, I would prefer that as long as the diagnostic yield is not affected by less contrast during the PVP.
Thanks again