Magnetic resonance imaging of the breast has been shown to be more sensitive than ultrasound or mammography for the detection of cancer. Despite this evidence, the use of MRI has not been demonstrated to produce better short-term outcomes: the prospective randomized COMICE trial failed to demonstrate a decrease in the positive margin rate and need for re-excision with the use of preoperative prone MRI. The COMICE study authors recognized that the inability of prone MRI to result in decreased positive margin rates might be due to the way the imaging data is presented to the surgeon, stating that ''techniques to ensure surgical precision is at an optimum need further examination.'' The shape of the breast during prone MR imaging (with the breast pendant in a bilateral imaging coil) is radically different from the supine, arm-extended position in the operating room (OR). Supine MRI more accurately replicates the surgical position. Indeed, a study by Sakakibara et al. randomized patients with DCIS to undergo wire localized or supine MRI- guided BCS and found the positive margin rate and resected tissue volume were lower in patients undergoing supine MRI-guided excision.