Virtual Colonoscopy

JASON GETZ / COX NEWS SERVICE A patient waits in the ready position before undergoing a virtual colonoscopy at St. Joseph's Hospital in Atlanta. Most insurance companies do not currently cover the procedure's $500 cost. Jiggering a computer mouse up, down and sideways like a teenager playing a video game, Dr. Tim Hanes guides his cursor through the curves and dips of a brown wrinkly tunnel that looks like it's out of Alice in Wonderland, searching for lurking monsters.

"Hey, there's one," said Hanes, a radiologist at St. Joseph's Hospital in Atlanta, pointing with his cursor to a glob on his computer screen that looks like a large gooey marble. "It's a big one."

The monster is a polyp, sprouting inside a patient's large intestine like a mushroom, and it's dangerous because many turn into malignant growths that cause nearly 150,000 cases of colon cancer a year, killing about 41,000 people.

Colon cancer is the second leading cause of cancer death behind lung cancer, which is why doctors say everyone 50 and over should be screened. The risk is greater for African-Americans, who are recommended for screening at age 45.

"It takes 10 years to go from a small polyp to colon cancer that'll kill you," said Hanes, 39.

He's sitting in front of a computer screen in a darkened room, diving ever deeper through the twists and turns of an anonymous patient's guts by means of a virtual colonoscopy — which transforms into lifelike 3-D images the innards of people moving slowly on a gurney through the doughnut hole of a CT scanner.

Virtual colonoscopies, a new, less-invasive procedure, creates images that are hard to distinguish from real pictures produced by cameras used in a conventional colonoscopy. In conventional colonoscopies, doctors use a colonoscope — a thin instrument tipped by a tiny camera — to snake through a patient's intestine, looking for pre-cancerous polyps and snipping them out when found.

The conventional procedure can take up to an hour and can be done in doctors' offices or hospital suites, and patients must be heavily sedated or put to sleep.

In virtual colonoscopies, which take 15 minutes or less, no sedation is required, because only a tiny, two-inch long catheter is inserted into the rectum. It pumps air into the colon to make it easier for the X-rays from the CT scanner to form better virtual images of polyps or other abnormalities.

Some people want to watch, but most are put to sleep.

Both methods require bowel cleansing the night before, which many patients dread more than the procedures themselves.

Still, patients are increasingly opting for the virtual procedure, even though it means they have to do the cleansing twice if polyps are found. When that happens, Hanes said, patients must go to a gastroenterologist to have the polyps removed.

The possibility of having to prep twice is a major disadvantage of the virtual procedure, which does have advantages. Patients don't have to be put to sleep and can be at work within a half hour of having the CT screening.

Those who undergo the conventional test must be heavily sedated, are often groggy for an entire day, and run the rare but dangerous risk of having their intestines perforated by the colonoscope.

Conventional colonoscopies can cost $3,000, which is almost always covered by insurance. The virtual screenings cost about $500, but usually aren't covered.

Hanes said the U.S. Department of Health and Human Services is expected to rule next month that the virtual procedure should be covered by Medicare. And if that happens, Hanes said, it's a good bet that private insurers will follow suit.