CHICAGO -- A type of computed tomography, or CT, scan promoted as a way to catch lung cancer early does not pass one research test.

According to Johns Hopkins researchers, the spiral CT is unproven, can lead to unnecessary follow-ups and probably would not be cost-effective as a screening tool. Their study is published in Wednesday's issue of the Journal of the American Medical Association.

Helical CT is a radiographic test that can provide high quality, three-dimensional images of the lungs during a single breath-hold and is more sensitive than a chest X-ray.

The procedure, which is advertised on TV and the Internet, can spot growths the size of a pea. But researchers said their computer modeling to see if the results would save lives indicates the benefit is not worth the cost.

In an accompanying editorial, Columbia University researchers wrote that people should put off the tests until further research can establish better whether the imaging is valuable.

For more information or to participate in the National Cancer Institute's lung cancer screening research, call (800) 422-6237.

Additional Resources:

• Journal of the American Medical Association
• National Cancer Institute