Summary Of Evidence

N/A

Analysis of Evidence

N/A

Indications

CT colonography, also known as virtual colonoscopy utilizes helical computed tomography 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 (fiberoptic, video) colonoscopy, as well as air 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. Virtual colonoscopy is intended for use in pre-operative planning only when imaging of the non-visualized colon proximal to the obstruction is medically necessary in making decisions involving the approach to the patient.

Incomplete colonoscopy must be due to one 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.

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

The following relative contraindications to instrument colonoscopy may be indications for virtual colonoscopy if well documented in the medical record and the patient's primary physician and the colonoscopist agree on the increased risk to the patient:

• Severe coagulopathy

• Long-term anticoagulation

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

Limitations
Virtual colonoscopy 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.

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

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