About 30%–40% of patients with three or more adenomas detected by CT colonography may be referred for a colonoscopy, compared with about 10% of patients who have a 1-cm or larger polyp detected by CT colonography, Dr. Rex said.
If CT colonography becomes well established as a result of additional studies that prove its effectiveness, gastroenterologists will be well-suited to read the 3-D fly-throughs of the colon created during CT colonography; many internal medicine subspecialists read their own radiology or ultrasound tests, Dr. Rex added.
Colorectal cancer screening with CT colonography currently must be performed with a high volume of patients to offset the major capital investments in CT colonography equipment. Insurance providers do not cover colorectal cancer screening with CT colonography, since no permanent CPT code exists yet for the test. Most parts of the country don't have a large enough population to make CT colonography screening feasible at the moment, he said.