MR imaging-guided axillary node biopsy for breast cancer: initial findings.

The aim of this study was to evaluate the usefulness and feasibility of preoperative sentinel node needle biopsy of the breast under guidance of open MR imaging, a method that we developed. Nine patients with breast cancer in whom the axillary lymph nodes were not palpable underwent preoperative sentinel node needle biopsy under real-time MR imaging guidance. The sentinel nodes were identified before the biopsy using CT and MR imaging. Diagnostic ability of this method was compared with that of the operative diagnosis. Sentinel nodes were correctly identified in all 9 patients. The MR imaging-guided sentinel node needle biopsy was performed for all of the 9 patients, and, in 7 (77.8%) of the 9, a specimen sufficient for pathologic evaluation was obtained; and in 6, whether malignancy existed was precisely diagnosed. No serious complications were noted. This experience indicates the possibility of a precise diagnosis of whether the sentinel node in breast cancer is benign or malignant without surgery.