Summary Of Evidence

N/A

Analysis of Evidence

N/A

Indications

Computed Tomography (CT) colonography, also known as virtual colonoscopy, utilizes helical CT of the abdomen and pelvis along with 2D or 3D reconstruction to visualize the colon lumen. The test requires colonic preparation similar to that required for instrument (e.g., fiberoptic, video) colonoscopy, as well as air or carbon dioxide insufflation to achieve colonic distention.

Virtual colonoscopy is only indicated in those patients in whom a diagnostic or surveillance instrument colonoscopy of the entire colon is incomplete due to an inability to fully pass the colonoscope proximally, and a repeat attempt is not indicated, or in patients with a valid contraindication to the safe performance of an instrument colonoscopy. Incomplete colonoscopy must be due to 1 of the following:

1. An obstructing neoplasm

2. Intrinsic scarring, stricture, aberrant anatomy, or obstruction from prior surgery, radiation, or diverticular disease

3. Extrinsic compression

There are few absolute contraindications to instrument colonoscopy. Relative contraindications do not create medical necessity for using CT colonography as a screening procedure, and the above indications must still be met.

The following relative contraindications to instrument colonoscopy may be indications for CT colonography if well documented in the medical record:

• Severe coagulopathy

• Long-term anticoagulation

• Increased sedation risk (such as from severe chronic obstructive pulmonary disease (COPD) or previous anesthesia adverse reaction)

Limitations

CT colonography is not covered when used for screening, or in the absence of signs or symptoms of disease, regardless of family history or other risk factors for the development of colonic disease.

CT colonography is not covered when used as an alternative to instrument colonoscopy for screening or in the absence of signs or symptoms of disease.

CT colonography is not covered following incomplete colonoscopy if the reason for the colonoscopy is other than one of those described above.

CT colonography is intended for use in pre-operative planning when imaging of the non-visualized colon proximal to the obstruction is necessary in making decisions involving the approach to the patient.