Medicare says it won't pay for the so-called virtual colonoscopy procedure.
Tuesday's announcement says there's inadequate evidence to support the cheaper, less intrusive alternative to the dreaded colonoscopy.
Some experts had hoped that popularizing the X-ray procedure would boost screening for colon cancer, the country's second leading cancer killer.
In a decision posted on its Web site, the Centers for Medicare and Medicaid Services says the test does not qualify for Medicare coverage. The memo also notes that the procedure is performed on people without symptoms and cannot, in itself, help rid a patient of precancerous growths, like a regular colonoscopy can.
CT colonography, also known as a virtual colonoscopy, is a super X-ray of the colon that is quicker and easier on the patient.