There may be a more effective way to detect breast cancer in women with dense breasts, according to a study released Sunday.

Molecular breast imaging (MBI) detects three times as many breast tumours as mammography in high-risk women with dense breast tissue, researchers at the Breast Cancer Symposium in Washington said.

MBI is a relatively new screening method wherein patients are injected with a radioactive agent that is absorbed by breast tissue. Cancer cells absorb more of the agent than healthy cells. A specialized camera tracks the agent and can distinguish between healthy tissue and cancer tumours.

Researchers screened 940 women with both MBI and mammography. All women had dense breasts or some other increased risk factor related to cancer, such as family history or genetic mutation.

Thirteen tumours were detected in 12 patients. Eight of those were detected by MBI and one by mammography. Used together, MBI and mammography detected 10 tumours.

Carrie B. Hruska, lead author of the study, said cancer can "hide" in dense tissue, and a combination of screening methods may be best.  

"These results suggest that MBI could become an important screening tool for women who have dense breast tissue and increased breast cancer risk," Hruska said.

MBI is low cost, about one-fifth of magnetic resonance imaging (MRI), and the images are easy to interpret, she said.

So far MBI screening is only available in certain cancer centres outside of Canada.

"Larger trials are needed to further validate our research, but it is encouraging to find that MBI can detect cancers that are not easily visible on screening mammography. Our next step will be to compare MBI prospectively to other screening methods such as MRI," she said.