Dear OncoLink "Ask The Experts,"
Carolyn Vachani RN, MSN, AOCN, OncoLink's Medical Correspondent, responds:
Magnification colonoscopy uses fiberoptic technology to magnify the view of the colon to about 75 to 100 times its normal size. As a point of comparison, standard colonoscopy uses 45-fold magnification. This test can be particularly helpful to diagnose "flat adenomas" (cancers that do not form as a polyp) or dysplasia (abnormal appearing tissue).
During the colonoscopy, the physician sprays a dye into the colon which highlights areas of dysplasia, based on the shape and appearance of the colon (called "pit pattern") and the uptake of dye. Magnification is needed to help the physician better and more fully visualize any areas of dye deposition. This procedure is used to screen for dysplasia and/or cancer in patients who are at high risk for colon cancer. High-risk patients typically have chronic colon inflammation (ie: irritable bowel disease, Crohn's disease, ulcerative colitis, primary sclerosing cholangitis, etc.).
Magnification colonoscopy is not yet used for general polyps.
The test is currently only available at a limited number of medical centers. The physician performing the test must be trained to recognize the "pit patterns" that signify dysplasia. If this sounds like a test for you, I would try the Gastroenterology department at large, academic centers in your area.