MRI-guided biopsy of bone in a hybrid system

This is a report of our experience with percutaneous, MRI-guided biopsies i n 25 patients with skeletal lesions ruing a 1.5-T MR hybrid system. Twenty- five consecutive patients with skeletal lesions were referred for MRI-guide d biopsy, Biopsies were performed with a 1.5-T Philips Gyroscan (Philips Me dical Systems, Best, The Netherlands) combined with a c-arm fluoroscopy. Sp ecimens were obtained percutaneously either with a le or 18-gauge "side-sli t" type of biopsy needle (n = 10 skeletal lesions that had penetrated throu gh the cortex), or using a prototype coaxial drill system powered either by hand or an optional motor (n = 15 skeletal lesions still covered with cort ical bone). All but two biopsies could be completed within the MR unit, For one patient, who required a transpedicular approach to a lumbar vertebra, and for one child, who required general anesthesia, we decided to switch to CT guidance. In 19 of the 25 cases (17 of the 23 cases performed in MR), t he sample was sufficient and the histopathologic diagnosis was confirmed. T hree patients had an inadequate sample, and three others had adequate sampl es but inaccurate results. No procedural complications occurred. Percutaneo us biopsy of skeletal lesions performed under MRI-guidance was found to be safe and reasonably accurate. There were no procedural complications in our small series, MRI may be used as an alternative to CT, but its role vis-a- vis CT has yet to be ascertained.