I am quite excited about this study but sad I was not the one to publish it. Out of South Florida, a study of 72 patients who received a NONCONTRAST CT Abdomen for various locations of abdominal pain.

Excluded were: trauma, pregnant, surgery in past 30 days, pain more than 3 days, MD discretion (thought usually to be suspicion for vascular emergency), unable to be reached for 7 day follow up, would not consent, unstable, suspected renal stone (as this is already the standard of care), known cancer, BMI < 18. Sounds like a lot of exclusions but this pared the population down to the general population of patients in whom I would consider the noncontrast CT abd for nonspecific abdominal pain. Notice suspicion for appendicitis was not an exclusion, many studies have shown minimal benefit to oral contrast in appendicitis. They also did not exclude very acute abdominal pain (ie using a minimum number of hours of pain).

The results: 0/72 patients had a missed diagnosis on the initial noncontrast CT. 3/72 had repeat contrasted studies which added little. Of the 31 patients discharged, no one had surgery, death, or repeat CTs done.

This is obviously a small sample at one hospital. Selection bias can be a factor, as MD discretion was an exclusion. I would love to see more studies like this, possibly RCTs. As more and more centers get the higher resolution CTs, we should see less and less contrast given for CT of the abdomen and pelvis.