Second-look targeted studies after breast magnetic resonance imaging: practical tips to improve lesion identification

Second-look studies, so-called because a re-evaluation of the breast is performed after review of magnetic resonance imaging (MRI) findings, offer the possibility of identifying correlates to MRI-detected lesions that were not previously suspected at mammography or ultrasound, thereby permitting immediate biopsy. To maximize the identification of ultrasound and mammographic correlates to MRI-identified lesions, one must carefully review the initial MRI examination as well as be cognizant of breast normal anatomy and variations in breast position across imaging modalities. We review the steps required for planification and realization of a successful second-look evaluation. After a correlate has been found and percutaneous biopsy performed, we recommend obtaining a T1-weighted noncontrast MRI sequence to verify metallic marker placement at the site of biopsy. This step ensures correct correlation between imaging modalities, provides immediate feedback for the radiologist, and, in case of error, allows the patient to be immediately redirected to repeat biopsy, often under MRI guidance. In the case of correct correlation, short-term follow-up is recommended, as for other breast percutaneous interventional procedures. We propose a simple management algorithm following second-look targeted studies.