Suspicious Breast Lesions Detected at 3.0 T Magnetic Resonance Imaging: Clinical and Histological Outcomes

Abstract

To evaluate the imaging features and histological and clinical outcomes of a series of suspicious, mammographically occult breast lesions detected at 3.0 T magnetic resonance imaging (MRI). Approval was obtained from the institutional review board. A Health Insurance Portability and Accountability Act-compliant retrospective review was performed of 121 suspicious, mammographically occult lesions detected on 3.0 T contrast-enhanced breast MRI. All 121 lesions underwent histological sampling. Radiology and clinic reports were reviewed for patient demographics, MRI indication and findings, biopsy and localization details, histological results, and follow-up information. Positive predictive value (PPV) of biopsy recommendations were calculated and compared for screening versus diagnostic cases. Likelihood of malignancy was also compared with lesion size. Statistical analyses were performed using chi-square, Fisher's exact, and two-tail z-tests. Overall 43 malignancies were diagnosed from 121 suspicious, mammographically occult 3.0 T MRI-detected lesions. Seventy-eight (64%) of the 121 were benign. The overall PPV of 3.0 T MRI-detected lesions was 36% (43/121). The PPV for biopsy in the screening setting (22% [10/45]) was statistically significantly less (P = .018) compared to the PPV of a biopsy recommendation in the diagnostic setting (43% [33/76]). There was no correlation between lesion size and the likelihood of detecting malignancy. Our PPV of suspicious, mammographically occult, breast lesions detected at 3.0 T breast MRI is similar to the PPV reported previously for suspicious breast lesions detected at 1.5 T. This study supports the use of 3.0 T breast MRI for both screening and diagnostic breast imaging.