In a study comparing four supplemental screening options for women with dense breast tissue, breast MR proved to be the most reliable for detecting breast cancers missed by mammograms.

Canadian researchers assessed handheld breast ultrasound, automated breast ultrasound and digital breast tomosynthesis as well, evaluating all four modalities in a meta-analysis of 22 studies that included 261,233 patients screened for breast cancer.

Of the patients, 132,166 had dense breasts and a negative mammogram. Supplemental screening picked up 541 cancers initially missed with mammography in this cohort of patients, with breast MR detecting the most.

No significant difference was found between the other three supplemental screening methods.

Study co-author Dr. Vivianne Freitas, assistant professor at the University of Toronto, Canada, and staff radiologist at the Joint Department of Medical Imaging in Toronto, says these and other findings on the role MR plays in supplementary screening will guide healthcare policies in the setting and direct future research, but there is more work to do.

"It is still early to advocate for wider application of breast MR in these women," she told HCB News. "Further evaluation of cost effectiveness of breast MR compared to other techniques, effect on mortality reduction, will need to be studied."

The meta-analysis consisted of ten studies covering handheld ultrasound, four testing automated breast ultrasound, three covering breast MR, and eight reporting on digital breast tomosynthesis.

Breast MR has become the preferred method for imaging women with a personal history of breast cancer.

One study published in August 2022 showed that postoperative surveillance breast MR may be a valuable tool for predicting a patient's risk for developing a second breast cancer, a higher risk for those with a personal history and even more so for those with dense breasts.

Another published in February 2022 found that those with a genetic predisposition who underwent MR between 30 and 35 have a more than 50% less chance of dying as a result.

While effective, breast MR is expensive, limiting its availability, as well as time-consuming and physically uncomfortable sometimes for patients. In March 2021, South Korean researchers found that abbreviated breast MR reduced scanning time from 30 minutes to about 10 minutes and in turn, its expense, though data on its performance was limited.

Clinicians may also not fully understand how to use it appropriately and its impact on treatment, particularly before surgery, according to researchers at the University of Milan in Italy who found an increased number of mastectomies following the scan, counteracting the trend in favor of breast conserving surgery.

"Regarding the cost, we hope that abbreviated MR may address this matter. It has demonstrated a similar sensitivity and specificity compared to a full breast MR protocol and currently have been investigated as an alternative to provide a more cost-effective modality," said Freitas.

The findings were published in Radiology.