Patients get a small injection of a radiotracer, then sit in a chair as the machine does the test.
The radiotracer goes straight to any tumors, and they show up as "hot spots."
Dr. Ann Moch says MBI is being used in addition to mammograms for women who run a high-risk of cancer, due to family history, genetics, or dense breast tissue.
"We've picked up lesions that haven't been seen on a mammogram and we've found breast cancers in people who might not have detected it for quite some time," said Dr. Moch.
Donna Reel was one of the first to get MBI screening at Capital Health.
Breast cancer runs in her family, and the cancer that took her mother's life was not picked up by mammograms until very late.
Although she gets regular mammograms, Reel says MBI gave her extra assurance.
"It was very easy…the doctor said I had textbook negative results so I was thrilled," said Reel.
Dr. Moch says MBI testing takes about half an hour, and has a very low false-positive rate.