Magnetic Resonance-Guided Biopsies and Localizations of the Breast

Objective: The objective of this study was to evaluate the performance of a new commercially available open breast coil and compatible intervention device (Machnet) for magnetic resonance image (MRI)-guided breast interventions. Materials and Methods: Breast lesions detected on MRI were evaluated using MRI-guided core biopsy (n = 20) and/or preoperative wire localization (n = 23) on histologic outcome and accuracy of localization. Time needed to perform a procedure and occurring problems were recorded. Results: Mean lesion size was <10 mm. Two of 20 lesions could not be biopsied because they were out of range for the device. Biopsies were conclusive in half of the cases; most lesions missed were <10 mm. The average accuracy for needle placement in the localization procedures was less than 2 mm (range, 0–5 mm). The average procedure time was 40 minutes for a biopsy procedure and 33 minutes for an MRI-guided localization. Conclusions: Preoperative MRI-guided localizations can be performed quickly and accurately. However, in MRI-guided core biopsies, especially in small lesions, the device does not guarantee conclusive histologic evaluation of the lesion targeted.