Characterization of breast lesions by magnetic resonance imaging (MRI) and spectroscopy (MRS)

Abstract

Breast cancer is a major health problem in women, worldwide. A combination of physical examination, mammography, ultrasound and fine needle aspiration cytology (FNAC) or core biopsy is currently the mainstay for preoperative diagnosis of breast lesions. Magnetic resonance imaging (MRI) has been proposed as a useful complimentary modality to provide additional information. It has shown potential in the detection, diagnosis and management of breast cancer. It can be used to improve preoperative staging, follow response to therapy, and to detect local recurrences. Contrast enhanced MRI (CEMRI) has evolved as an important tool in the evaluation of breast abnormalities with high sensitivity (94-100%), but with poor specificity. Recently, diffusion and perfusion MRI techniques have been applied to breast lesion characterization and show promise but warrant further investigations. Characterization of breast lesions may also be assisted by using information of the cellular chemistry provided by in vivo proton MR spectroscopy (MRS). Recent reports have shown that neoplastic breast tissue contains elevated levels of choline containing compounds, which can be used as a biochemical marker for differentiating benign versus malignant tumor and for monitoring treatment response. Presently, the various MR techniques show promise primarily as adjunct to the existing standard detection techniques, and its acceptability as a primary screening method will increase only if specificity can be increased. This review presents the current status of MRI and MRS in breast imaging.