Molecular breast imaging (MBI) is a functional imaging modality that utilizes technetium 99m sestamibi radiotracer uptake to evaluate the biology of breast tumors. Molecular breast imaging can be a useful tool for supplemental screening of women with dense breasts, for breast cancer diagnosis and staging, and for evaluation of treatment response in patients with breast cancer undergoing neoadjuvant systemic therapy. In addition, MBI is useful in problem-solving when mammography and US imaging are insufficient to arrive at a definite diagnosis and for patients who cannot undergo breast MRI. Based on the BI-RADS lexicon, a standardized lexicon has been developed to aid radiologists in MBI reporting. In this article, we review MBI equipment, procedures, and lexicon
clinical indications for MBI
and the radiation dose associated with MBI.