New research shows there is a better screening option for women with dense breasts. Dense breast tissue makes it difficult to identify cancer on a mammogram, and women with dense breasts are at an increased risk of developing breast cancer in their lifetime. More than half of women over age 40 have dense breasts.

The study, published in JAMA, compares abbreviated breast magnetic resonance imaging (MRI) with digital breast tomosyntheses (DBT).

DBT is a special type of mammogram that uses x-rays to detect breast cancers. Also known as a 3D mammogram, it finds more cancers than a standard mammogram and results in fewer recalls for additional imaging in patients who don’t have cancer.

An MRI is a non-x-ray method that requires intravenous contrast. It is routinely used in women who are genetic mutation carriers, have had prolonged radiation to their chest and women with an estimated lifetime risk of more than 20% for developing breast cancers. An abbreviated MRI means less time for the patient—in about ten minutes the machine can capture enough images for the radiologist to detect the greatest number of breast cancers.

The study found when screening more than 1,400 average-risk women with dense breasts, abbreviated MRIs had a significantly higher rate of invasive breast cancer detection than DBT. The abbreviated MRI detected 22 of the 23 cancers, while DBT detected cancer in nine out of 23.

“If you wish to identify the greatest number of breast cancers, breast MRI is best,” said Dr. Bethany Niell, section chief of Breast Imaging at Moffitt Cancer Center. “MRI exams find more breast cancers than mammograms, DBT or ultrasound.”

There are downsides to breast MRIs, however. They are more expensive than standard mammography or DBT and they result in more biopsy recommendations.

Niell says it’s important to note MRI should not be done instead of mammography, but rather in addition to. Women who are at high risk should still be getting a mammogram or DBT every year. Those who are getting supplemental screening with MRI do not also need supplemental screening with ultrasound.

Researchers say while the early results are promising, further studies are needed to evaluate the cost-effectiveness of widespread screening with abbreviated MRIs and its impact on reducing breast cancer mortality.