Objective: Core needle biopsy has proven advantages for wire localization and excision; however, MRI-guided core biopsy has been limited by less satisfactory sampling efficiency and less availability of MRI-compatible biopsy needles. We evaluated the feasibility and diagnostic yield of MRI-guided biopsy using 14-gauge stainless steel core biopsy needles and MRI-compatible coaxial sheaths in a closed 1.5-T scanner.
Materials and methods: Thirty-five consecutive breast biopsies performed in 29 women between March 2001 and August 2002 were retrospectively reviewed. For each procedure, an MRI-compatible sheath was placed under MRI guidance using a dedicated breast coil and biopsy guidance system. With the patient out of the magnet, a 14-gauge steel core biopsy needle was used to obtain multiple samples. Lesion characteristics, including size, morphology, and enhancement, were recorded. Histology of all the lesions was obtained; and surgical, imaging, or clinical follow-up was performed.
Results: Targeted masses and enhancing foci ranged from 3 to 17 mm. Regional enhancement ranged from 14 to 70 mm. Thirty-four of the 35 biopsies were technically successful. Histology revealed malignancy in eight lesions (23%), atypical ductal hyperplasia in five lesions (14%), and benign entities in 21 lesions (60%). Surgery confirmed all eight core biopsies with malignant findings. Two of five lesions with atypical ductal hyperplasia were upgraded to malignancy after surgery.
Conclusion: This new method of MRI-guided breast biopsy with a 14-gauge stainless steel core biopsy needle and a closed 1.5-T MRI scanner is feasible, safe, and effective and produces satisfactory diagnostic yield. This method offers an alternative to MRI-guided wire localization and to MRI-guided core biopsy with nonferrous needles.