Molecular Breast imaging and breast specific Gamma Imaging for cancer screening

What are MBI and BSGI?

Breast specific Gamma Radiation and Molecular breast imaging are essentially nuclear medicine techniques for breast imaging. Both of them require a radioactive agent to be injected into the patient intravenously.

Due to the difference in equipment a higher dose of radiation is required for BSGI than MBI. MBI and BSGI are especially useful for diagnosis of cancer in dense breasts.

How it works

Cancer cells absorb more of the radioactive agent injected into the patient’s body compared to normal cells. This allows the cancer to become visible due to difference in metabolism. 5 minutes after the radiotracer is injected intravenously, each breast is gently stabilized between two detectors or between a detector and a compression paddle. 10 minutes are given per view and the positioning is similar to that for mammography. The basic difference between mammography and these techniques is that this technique does not look at the anatomy of the breast as a mammogram or ultrasound does. Instead it looks at the functional behavior of the breast tissue which becomes visible due to the difference in uptake of the radioactive agent.

Benefits

If used with a low radiation dose protocol, MBI is able to detect additional 7 to 8 cancers per thousand women when compared to only mammography and is now being used in usual clinical practice. MBI and BSGI are also useful in case of women who cannot tolerate MRI due to kidney failure, claustrophobia or have pacemakers or any kind of metallic implants. MBI and BSGI can be used in case of women with dense breast tissue and show up a suspicious area on mammogram which is not identifiable by ultrasound. In uncommon cases lumps of areas of scarring remain a concern once mammography and ultrasound are done but cannot be biopsied with mammography or ultrasound. In these cases also MBI can be used for further evaluation.