December 2 (HealthDay News) -- Colorectal cancer and osteoporosis are very different diseases that a single test may be able to accurately detect, a new study says.

A virtual colonoscopy is often used to detect precancerous polyps in the large intestine. A presentation, expected to be made Monday in Chicago at the annual meeting of the Radiological Society of North America, will show how the imaging from this test can measure bone density to check for osteoporosis, a disease in which bones become fragile and more likely to break.

In a CT colonography, an abdominal CT scan is done to create cross-sectional images of the abdomen and spine. Computer software then arranges the images to create an interior or "fly-through" view of the colon as would be seen in a conventional colonoscopy. A different software application can convert these into three-dimensional images of the spine to check the patient's bone mineral density. Low bone mineral density is usually associated with osteoporosis.

The results of the study on 35 people showed the data from the CT colonography images agreed with the subject's DEXA bone mineral density scores normally used to check for osteoporosis.

"CT colonography isnt a replacement for DEXA testing, but it could be a way to screen more people for osteoporosis," lead author Rizwan Aslam, assistant clinical professor of radiology at the University of California, San Francisco, said in a news release issued by the meeting's organizer. "When an individual undergoes CT colonography, we can also obtain a bone density measurement with no additional radiation and at minimal cost."

According to the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases, 10 million Americans aged 50 or older have osteoporosis, while another 34 million are at risk due to low bone mass. Detecting osteoporosis early provides for early intervention and treatment.

SOURCE: Radiological Society of North America, news release, Dec. 2, 2008