Frequency and Outcomes of Incidental Breast Lesions Detected on Abdominal MRI Over a 7-Year Period.

OBJECTIVE: Our aim was to evaluate the frequency and outcomes of incidental breast lesions detected on abdominal MRI examinations. MATERIALS AND METHODS: Abdominal MRI reports for 11,462 women imaged at our institution from November 2007 through December 2014 were reviewed to identify those reporting an incidental breast lesion. Available breast imaging and pathology results were assessed to identify outcomes in these lesions. RESULTS: Incidental breast lesions were described in the MRI reports of 292 (3%) patients who underwent abdominal MRI during the study period; breast imaging was recommended for 192 of these 292 (66%) patients. Sixty-three of the 192 (33%) patients for whom follow-up breast imaging was recommended underwent such imaging at our institution. Twenty-one of these 63 (33%) lesions underwent biopsy or surgery; histologic sampling of these lesions yielded seven incidental cancers (invasive ductal, n = 6; invasive lobular, n = 1) and 14 benign diagnoses. Three additional cancers (invasive ductal, n = 2; invasive lobular, n = 1) and three benign diagnoses were discovered at pathology at outside institutions. Of the remaining 165 patients without a histologic diagnosis, the lesions in 95 (58%) patients were presumed to be benign because of stability over time. Seven of the 10 patients with a diagnosis of incidental cancer (age range, 53-86 years; mean ± SD, 67.0 ± 10.6 years) had not undergone screening mammography at our institution. The frequency of incidental breast cancer was 11% of patients subsequently undergoing follow-up breast imaging at our institution, 3% of all patients with reported breast lesions, and 0.09% of patients undergoing abdominal MRI examinations. CONCLUSION: Although incidental breast lesions were rarely detected on abdominal MRI, a considerable number of these lesions were found to represent breast cancer, particularly when leading to a recommendation for follow-up breast imaging. Therefore, it is important for radiologists interpreting abdominal MRI examinations to carefully evaluate for the presence of breast abnormalities.

Investigation of Multisequence Magnetic Resonance Imaging for Detection of Recurrent Tumor After Transurethral Resection for Bladder Cancer.

PURPOSE: The aim of this study was to evaluate multisequence magnetic resonance imaging (MRI) in detecting local recurrence after transurethral resection for bladder cancer. METHODS: Thirty-six patients with bladder cancer with previous transurethral resection underwent bladder MRI incorporating T2-weighted imaging, diffusion-weighted imaging, and delayed contrast-enhanced T1-weighted imaging, followed by cystoscopy. Two radiologists (R1 and R2) evaluated examinations for suspicious findings. RESULTS: Forty-seven percent of patients had recurrent tumor at cystoscopy and biopsy. Using multisequence MRI, sensitivity and specificity were 67% and 81% for R1 and 73% and 62% for R2. Both readers missed 1 high-grade pathologic stage T1 recurrent tumor; otherwise, all missed tumors were low-grade pathologic stage Ta lesions. All false positives for R1 and 7 of 9 false positives for R2 were in patients receiving previous bacillus Calmette-Guerin therapy. Furthermore, 40% to 50% of solitary abnormalities and 83% to 100% of multifocal abnormalities were tumor recurrences; 12% to 20% of smooth wall thickening, 50% to 75% of irregular wall thickening, and 88% to 100% of papillary masses were tumor recurrences. CONCLUSIONS: Although multisequence MRI exhibited moderate performance for detecting recurrent tumor, nearly all missed tumors were low grade and noninvasive.