Breast Cancer: Comparative Effectiveness of Positron Emission Mammography and MR Imaging in Presurgical Planning for the Ipsilateral Breast

Overall, 61 (16%) of 388 participants had an appropriate change in surgical management based on MR findings—more than the 41 (11%) participants with an appropriate change based on positron emission mammography (PEM) findings (P = .003) and fewer than the 71 (18%) participants with an appropriate change based on combined PEM and MR findings (P = .004 for comparison with MR imaging alone); 25 (6.4%) women had excessive excisions on the basis of MR findings compared with 19 (4.9%) women who had them on the basis of PEM findings (P = .26) and 32 (8.2%) women who had them after undergoing combined PEM and MR imaging (P = .023 for comparison with MR imaging alone).