Some encouraging news on “virtual”, or CT, colonoscopy. A study in the NEJM (needs subscription) concluded that CT colonoscopy identified 90% of polyps or cancers measuring 10mm or more in diameter.

Before jumping in line however, consider the following:

i) You still need to undergo a bowel prep prior to the procedure. This is often more uncomfortable than the colonoscopy itself.

ii) If something is found on the CT colonoscopy, a “real” endoscopy would be needed to biopsy the lesion.

iii) Radiation exposure is relatively high with a CT colonoscopy. Although the dose from a single test is acceptable, repeated screenings with CT colonoscopies can result in substantial cumulative radiation exposure.

iv) Incidental findings (not related to the bowel) that warranted additional testing occurred in 16 percent of cases. This can necessitate further, possibly unnecessary, testing.

v) Smaller (<10mm) lesions were missed in 10 percent of patients. This doesn’t rule out CT colonoscopy as a screening test. It does have tremendous promise. Just be aware of the drawbacks when reading the media hype on the study.