MR IMAGING-GUIDED LOCALIZATION AND BIOPSY OF BREAST-LESIONS - INITIAL EXPERIENCE

PURPOSE: To evaluate the usefulness of a magnetic resonance (MR) imaging-guided system for localization and biopsy of mammographically and clinically occult breast lesions. MATERIALS AND METHODS: The 11 needle localizations and one cyst aspiration were performed with MR imaging guidance in 11 patients with breast lesions. Two MR systems were tested; both required the patient to lie prone with the breast compressed between medial and lateral plates. One system used a grid with 18-gauge holes placed at 5-mm intervals and two reference markers to position the needle; the other, a stereotaxic external needle guide and a software system to calculate coordinates. RESULTS: Fibroadenoma, ductal carcinoma in situ, invasive ductal carcinoma, atypical ductal hyperplasia, fat necrosis, and sclerosing adenosis were found at histologic examination. In two cases, biopsies revealed multifocal breast cancer where mammographic and clinical findings had indicated a single lesion. CONCLUSION: MR imaging-guided needle localizations may be performed in a clinical setting with the systems described. Accurate localization of;mammographically and clinically occult lesions will allow MR imaging to achieve a clinically significant role.