WEDNESDAY, May 4 (HealthDay News) -- Breast shields are the best way to protect the breasts of women from radiation exposure while they have a chest CT examination, according to a new study.

The researchers compared a breast shield with a new technique called posteriorly centered partial CT, in which the CT scanner turns on and off as it scans the patient.

For each approach, the team at Penn State Hershey Medical Center measured the radiation dose to the front and back of an object called a breast phantom, which mimics the size of the breast area of a woman.

"We found that posteriorly centered partial CT does decrease skin entrance radiation dose to the breast by 16 percent, but increases overall radiation dose to the chest by 8 percent," lead author Dr. Rafel Tappouni said in an American Roentgen Ray Society news release.

"The bismuth breast shields, on the other hand, reduced skin entrance dose to the breast by 38 percent without an increase in overall radiation dose," he added.

The study was to be presented Wednesday at the society's annual meeting in Chicago. Research presented at meetings is considered preliminary because it has not been subject to the scrutiny required for publication in a peer-reviewed journal.

More information

The U.S. Food and Drug Administration has more about radiation risks from CT.