They are particularly effective in detecting and evaluating cancer in the liver, pancreas, adrenal glands, lungs, and bones. They are also used to provide information about cancer in the large and small intestines, esophagus, stomach, brain, prostate, or other organs.

A recent article published in the New England Journal of Medicine has raised concerns over the potential risks involved with undergoing a CT scan. By comparing risk estimates from the studies of the atomic bomb survivors from World War II with CT scan usage from 1991 through 1996, the authors state that an increase in the use of CT scans may cause 1.5% to 2% of all cancers in the future.

While studies show that these survivors had an increased risk of cancer, it’s important to realize that those radiation doses could not be regulated and were sustained for longer periods of time than that of a single CT scan.

No large-scale studies of the cancer risks associated with CT scans have been conducted yet. While the risk with a single CT scan is very low, in the future we hope to have a better understanding of exactly what the cancer risk from multiple scans could amount to.

Dr. Len Lichtenfeld, ACS Deputy Chief Medical Officer, encourages patients to consider both the benefits and the risks of a CT scan.

"You shouldn’t refuse a CT scan when you have to have one. They are an incredibly useful tool," says Dr Lichtenfeld. "But you shouldn’t have a CT scan without being aware that there are some risks, especially if it is a scan that is not going to impact the course of a diagnostic work-up or influence your treatment. Getting a CT scan just to get a scan is not a good idea."

Take time to consider these issues before undergoing a CT scan:

• Be aware that every test and type of medicine has some sort of risk attached to it.
• Ask your doctor whether you really need the scan and whether it is going to make a difference in your treatment.
• Ask your doctor whether there is another test option (such as an ultrasound) that can provide the same information with less radiation risk.
• Make certain your scan is done on modern equipment and that the machine is set for the lowest radiation dose for your particular scan and circumstance.

As with any medical decision, you should consult your doctor and discuss what is best for you. For more information on imaging tests that are used to detect cancer, visit www.cancer.org/radiology or call 1-800-ACS-2345.