What a Virtual Colonoscopy Is
Colorectal cancer is the 2nd leading cause of cancer deaths, but 95% of these deaths are preventable with screening. The American Cancer Society recommends that all adults over the age of 50 be screened for colorectal cancer by one of several methods, including virtual colonoscopy. These screening methods look for polyps and other indications of cancer within the colon and rectum. Currently, only 30% of those who should get screening do so.
Virtual colonoscopy, also known as CT colonography, is a colorectal cancer screening method using a CT scan to view the inside of the colon. Sophisticated computer software combines the CT images to form a three dimensional image of the colon, similar to what is seen during a conventional colonoscopy. All methods of screening for colon cancer require a cleansing regimen for the colon. A virtual colonoscopy does not require the insertion of a camera through the colon as a conventional colonoscopy does. Additionally, the colon does not need to be filled with liquid barium as with a barium enema. Consequently, a virtual colonoscopy tends to be significantly faster and more comfortable for patients than other common screening methods.
Conventional (fiber optic) colonoscopies have been considered the “gold standard” for colorectal cancer screening. Many studies have been conducted to compare the accuracy of virtual to conventional colonoscopies in finding tumors and polyps in the colon. Study results show that virtual colonoscopies are as accurate as or even exceed conventional colonoscopies at finding tumors and polyps of significant size. An additional benefit of CT colonography is that the radiologist can also see other abdominal structures in the CT scan images, which may enable him or her to identify other health problems when examining the images.
A limitation of virtual colonoscopies is the inability of the radiologist to remove a polyp during the procedure. If polyps are found, as happens about 10% of the time, the patient must undergo a conventional colonoscopy so they can be removed. Consequently, virtual colonoscopies are most appropriate for individuals who are not at high risk for colorectal cancer and not experiencing any symptoms of colorectal cancer.
Invision Sally Jobe offers virtual colonoscopies at our outpatient center in Littleton, Colorado.