Preoperative MR imaging-guided needle localization of breast lesions.

Objective: MR imaging of the breast can depict cancer that is occult on mammography and at physical examination. Our study was undertaken to determine the ease of performance and the outcome of MR imaging-guided needle localization and surgical excision of breast lesions.

Materials And Methods: Retrospective review revealed 101 consecutive breast lesions that had preoperative MR imaging-guided needle localization with commercially available equipment, including a 1.5-T magnet with a breast surface coil, a dedicated biopsy compression device, and MR imaging-compatible hookwires. Imaging studies and medical records were reviewed.

Results: Histologic findings in these 101 lesions were carcinoma in 31 (30.7%), high-risk lesions (atypical ductal hyperplasia or lobular carcinoma in situ) in nine (8.9%), and benign lesions in 61 (60.4%). Fifteen (48.4%) of 31 carcinomas were ductal carcinoma in situ, and 16 (51.6%) were infiltrating carcinoma (size range, 0.1-2.0 cm; median, 1.2 cm). Carcinoma was found in 16 (45.7%) of 35 lesions detected in women with synchronous cancer, 10 (32.3%) of 31 lesions detected on MR imaging for problem solving, and five (14.3%) of 35 lesions detected on MR screening. The time range to perform MR imaging-guided localization was 15-59 min (median time, 31 min). Complications encountered in three cases were retained wire fragments in two and breakage of the wire tip in one.

Conclusion: MR imaging-guided needle localization can be performed quickly and safely with commercially available equipment. The positive predictive value of MR imaging-guided needle localization (30.7%) was comparable to that reported for mammographically guided needle localization and was highest in women with synchronous breast cancer.