Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: TUESDAY, March 28, 1995                   TAG: 9503280073
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-1   EDITION: METRO 
SOURCE: Associated Press
DATELINE: NEW ORLEANS                                LENGTH: Medium

`VIRTUAL' COLON EXAM ELIMINATES THE TUBE

Dr. David J. Vining of Wake Forest University, the principal developer of the new method, calls it ``virtual colonoscopy,'' a way to combine X-rays and computers to examine the entire colon without actually putting anything into it except air.

The new approach yields a 3-D, from-the-inside view of the colon that doctors can explore by moving a joy stick while watching the passing bumps and crevices on a computer screen.

Colon cancer is the No.2 cancer killer of men and women after lung cancer. This year, an estimated 55,300 Americans will die from it.

The mainstay of screening for this disease is a skinny, flexible tube that is inserted through the rectum into the colon. The doctor looks through the tube for growths called polyps that might be cancerous.

The American Cancer Society and other health organizations recommend that people over 50 be checked with sigmoidoscopy, an exam of the lower third of the colon, every three to five years. If this reveals any possible problems, the next step is colonoscopy, which uses a longer tube to view the entire 4 to 6 feet of the colon.

Vining's idea, which he said was inspired by computer games, involves a relatively new form of X-ray technology called spiral CT. Ordinary CT scanners slowly take cross-sectional images of the body, one picture at the time. The new machine spins around the patient and snaps 400 to 500 pictures in half a minute.

Vining uses two commercially available software programs to process the data and turn it into a 3-D image. He has tested it on 20 patients who were about to undergo regular colonoscopy. It accurately found the four who had cancer.

Before undergoing the test, patients must have their bowels flushed. Then air is pumped into their colons. The exam itself takes just 30 seconds, and unlike colonoscopy, no sedation is required.

Vining estimated that an exam will cost $450 to $650, compared with $900 to $1,800 for colonoscopy. However, colonoscopy will still be necessary to remove polyps after doctors spot them with virtual colonoscopy.

There is a drawback to the new method: Bits of fecal matter can be mistaken for polyps. So Vining is working with a manufacturer to develop a contrast material that patients can drink a few days before their test. It should allow doctors to distinguish feces from polyps without the need for colon cleansing.