BOSTON (Reuters) -- The latest CT-scan technique that yields three-dimensional images of the bowel is faster, simpler and safer than the standard colon exam for preventing colon cancer, researchers said on Monday.

If the finding is confirmed and some lingering questions about the technique are answered, such "virtual" colonoscopies could become commonplace, said Martina Morrin and Thomas LaMont in an editorial in the New England Journal of Medicine, where the study will be published on Thursday.

The study was presented last Monday at the annual meeting of the Radiological Society of North America in Chicago.

Using a scan avoids having to sedate a patient and doctors do not have to put a probe up the length of the colon, both of which can cause problems.

However, people being screened using either method will still have to follow an often distasteful regimen for cleaning the bowel. And if something suspicious is found using the CT scan technique, patients will still need a conventional colonoscopy to have suspicious polyps removed.

Colon cancer kills 60,000 people in the United States each year, making it the second leading cause of cancer deaths. Having a colonoscopy every three to five years after age 50 virtually eliminates that risk.

Only a third to half of the population is screened for colon cancer, and a safer, simpler technique might get more people into screening programs.

Morrin and LaMont said it was unclear whether virtual colonoscopies would save money or whether health insurance companies would pay for the procedure. Also unclear was whether doctors should remove small polyps found by the CT scan right away. ---Special Software---

The research team led by Perry Pickhardt of the University of Wisconsin Medical School, used CT scanners with multiple detectors that picked up fine details more quickly than conventional scanners.

They also had special software that permitted doctors to view the colon in three dimensions and ignore any material lingering in the bowel.