Virtual Colonography (CT Colonography) - Department of Radiology

Overview

Virtual colonography or computed tomography colonography is a noninvasive procedure that uses computed tomography scanning to determine the presence of colon polyps.

The VCU Department of Radiology was among the first in Virginia to test and use more patient-friendly methods of screening for colon polyps. Virtual colonography relies on specially developed computer software to recreate the inside of the patient’s colon using two-dimensional and three-dimensional images. The process allows a “fly-through” or “virtual” evaluation of the colon that provides the precise location and size of colon polyps.

Identification and removal of colon polyps before they become cancerous is the purpose of colon screening. Early studies show that virtual colonography is comparable to conventional colonography in terms of identifying polyps six millimeters or greater in size. Virtual colonography makes it possible to evaluate the entire colon, without risk of bowel perforation, or complications from sedation associated with standard colonography.

The VCU Department of Radiology uses virtual colonography as a diagnostic tool to confirm or rule out the possibility of cancer. If large polyps are identified, traditional colonoscopy is required for biopsy and removal.

Early Detection

Left undetected, colon polyps larger than 7 to 10 millimeters are at risk of developing into colon cancer. If polyps are removed early on, colon cancer is preventable. Research shows that less than 40 percent of those who should be screened actually do so.

Screening

According to the American Cancer Society, cancers of the colon and rectum combined are the third most common cancer for both men and women, and the second leading cause of cancer-related deaths. Screening and early removal of colon polyps can prevent the development of cancer. Although there are high-risk determinants, 75 percent of all colon cancer cases occur in people with no known predisposing factors.