Digital breast tomosynthesis, better known as 3-D mammography, can find more invasive, and in some cases more dangerous, cancers than a traditional digital mammogram, a new study published in the Journal of the American Medical Association this week concludes.

But do you need one?

Approved by the Food and Drug Administration in 2011 as a supplement to digital mammography, tomosynthesis creates a 3-D reconstruction of the breast tissue, giving radiologists a clearer view of overlapping slices. This new study found using the combination of digital and 3-D mammography reduces false alarms and unnecessary call backs by 15% in all groups of patients, including younger women and women with dense breast tissue.

The study was funded by Hologic, the manufacturer of the 3-D imaging machine, and the National Cancer Institute.

"3-D mammography finds more clinically significant breast cancers earlier... so that women have more treatment options and ultimately better health outcomes," said Dr. Emily F. Conant, senior author of the new study and chief of breast imaging in the Department of Radiology at the Perelman School of Medicine at the University of Pennsylvania.

Unfortunately, 3-D mammography images cost more and are not yet available everywhere. Depending on where a woman lives and her insurance, tomosynthesis may or may not be covered.

Robert Smith, senior director of cancer screening at the American Cancer Society, says the decision of whether to spring for the 3-D test is best left up to physicians to decide with their patients. But women should know that these images result in more detection of abnormal cells and therefore, more biopsies, he says.

Experts believe women with dense breast tissue and women who may have scar tissue from breast surgery or biopsies can benefit most from the accuracy of 3-D mammograms.

For women who can’t afford the extra fee, or who simply ask, "Is it worth it?" Smith says a standard digital mammogram is fine.

The best thing for women to do is strictly follow recommendations for regular mammograms at an imaging center that has mammography experts on hand. Getting regular mammograms enables your doctor to easily compare your current images with previous scans, which can reduce false-positive test results.

Smith predicts the decision will eventually be made for women as 3-D mammography becomes offered more widely, ultimately replacing standard mammography. Until then he says, “The jury is still out and the attorney for one side is feeling more confident than the other.”