ROLE OF BREAST MRI IN PATIENTS WITH SUSPICIOUS MICROCALCIFICATIONS ON MAMMOGRAPHY

Abstract

Breast cancer is the second most common cancer affecting females, and the key to survival lies in early detection and treatment. Microcalcifications can be the early and only presenting sign of breast cancer. Around 75% of the time, microcalcifications are the sole finding of DCIS, and about 15% of the time, they are present along with a soft-tissue abnormality.Approximately 90% of the time, DCIS appears as microcalcifications at mammography; calcifica¬tions may be amorphous, coarse, heterogeneous, or fine pleomorphic with a clustered, linear, or segmental distributionDuctal carcinoma in situ (DCIS) is a noninva¬sive malignancy and a nonobligate precursor to invasive cancer. At pathologic analysis, DCIS shows proliferation of malignant epithelial cells that line a terminal ductal–lobular unit without invasion through the basement membrane. Magnetic resonance imaging is the first breast imaging modality that not only allows detailed visualization of the anatomy but also, when an intravenous contrast agent is administered or advanced sequences (e.g., diffusion-weighted imaging or spectroscopy) are used, provides functional informationMore recent studies have been conducted at higher spatial resolution and have increasingly been performed to screen higher-risk women as well as to evaluate extent of disease. The sen¬sitivity of MR imaging for detection of DCIS has been shown to be higher for high-grade and intermediate-grade DCIS as compared with low-grade DCIS (98%, 91%, and 80%, respectively). Overall, MR imaging is more sensitive than mam¬mography in the detection of all grades of DCIS. Over the past decade, studies have shown that the sensitivity of MR imaging for DCIS has improved significantly and is much higher than that of mammography (92% vs 56%, respec¬tively). DCIS is usually not visible on non–contrast material– enhanced T1-weighted images or on non–fat-saturated or fat-saturated T2-weighted images because it is masked by the normal breast pa¬renchyma.DCIS most commonly manifests as NME, Less frequently, DCIS manifests as a mass or as a focus. NME is defined as enhancement of an area that is not a mass. and can manifest with various internal en-hancement patterns, the most common of which is a clumped pattern, fol¬lowed by a heterogeneous pattern. as well as clustered ring enhancement. Clustered ring enhance¬ment, a term in the new MR imaging BI-RADS lexicon, represents peri-ductal enhancement and is the result of contrast material pooling in the periductalstroma or ductal wall of DCIS. In kinetic Characterization of DCIS the most common initial phase is fast uptake, the delayed phase is more variable,