WASHINGTON — A better mammogram? Increasingly women are asked if they want a 3-D mammogram instead of the regular X-ray. Now U.S. health officials are starting a huge study to tell if the newer, sometimes pricier choice really improves screening for breast cancer.

The 3-D mammograms have been marketed as being able to find more cancers. But there are trade-offs, and researchers say it’s important to learn if the scans really pinpoint life-threatening cancers without increasing false alarms or spotting tumors that grow so slowly they never would have posed a risk.

About 165,000 women will be recruited for the study funded by the National Cancer Institute.

Researchers also hope the findings will clear up some of the confusion about when women should start getting mammograms and how often.

Lauran Neergaard, The Associated Press