Unenhanced magnetic resonance screening using fused diffusion-weighted imaging and maximum-intensity projection in patients with a personal history of breast cancer: role of fused DWI for postoperative screening.

Abstract

To assess the diagnostic performance of unenhanced abbreviated protocol (AP) comprising fused diffusion-weighted imaging (DWI) using T1-weighted imaging (T1WI) with DWI maximum-intensity projections (DWI MIPs) for screening patients with a personal history of breast cancer (PHBC). This institutional review board-approved retrospective observational study included 343 patients with PHBC who underwent 3T breast magnetic resonance imaging (MRI) between November 2013 and September 2015. Three breast radiologists reviewed the DWI MIPs of the AP to identify lesions, and the remaining axial AP images to characterize the detected lesions and establish the breast imaging reporting and data system final assessment. The conventional protocol (CP) images were also evaluated in the same way. The decision-making times were recorded. MRI acquisition time was approximately 5min for AP. The mean times to read MIPs and remaining images were shorter in AP than in CP (5.5 and 22.1s vs. 7.8 and 29.6s). On DWI MIPs, the readers detected 9, 8, and 9 of 9 pathologically proven cancers, with negative predictive values (NPVs) of 100.0, 99.6, and 100.0%. Complete AP showed sensitivities of 88.9, 100.0, and 88.9% and specificities of 94.8, 93.4, and 95.1%. Complete CP showed sensitivities of 100.0, 100.0, and 88.9% and specificities of 93.4, 94.0, and 96.3%. An unenhanced AP had a short acquisition time of 5min, and DWI MIPs showed NPVs greater than 99% across readers. The diagnostic performance of complete AP was equivalent to that of CP for screening patients with PHBC.