MRI-guided Needle Localization for Breast Lesions Occult in Mammograms and Ultrasound

To evaluate the diagnostic eff icacy of breast magnetic resonance imaging (MRI)-guided needle localization and surgical biopsy for suspicious breast lesions occult on physical breast examination, mammography and second-look ultrasound. Twelve patients (age range, 29-68 years; mean 44.9±9.24 years) received breast MR-guided needle localization and surgical biopsy for the suspicious lesions detected by breast MRI only. All procedures were successfully performed in a 1.5T MR system equipped with dedicated breast biopsy system. Eleven of the patients received lateral approach and one received medial approach with a 20 -gauge MR-compatible local izat ion needle. Contrast enhancement was given before or after deployment of the hookwire to confirm the location of the hookwire and the suspicious breast lesion. The size of breast lesions ranged from 0.6 to 5 cm (mean±SD, 1.44±1.29cm). Final pathologic diagnoses from surgical specimens included two low grade ductal carcinoma in situ (16.7%). There were three lesions (25%) diagnosed as pre-malignant or high risk lesions, including 1 lobular carcinoma in situ (LCIS) and atypical ductal hyperplasia (ADH), 1 atypical lobular hyperplasia (ALH) and papilloma, and 1 ADH. Seven lesions (58.3%) were benign f ibrocystic change (n=5), f ibroadenomatous change (n=1) and an intraductal papilloma (n=1). There was no procedurerelated complication. No def inite abnormality was found in specimen mammograms in seven patients. MR I-guided needle local i zat ion of breast lesions provides a confident approach for suspicious lesions detected only on MRI which cannot be biopsied under ultrasound or mammography guidance.