New Trends in Musculoskeletal Interventional Radiology: Percutaneous, MR_Guided Skeletal Biopsy

Several different types of magnetic resonance (MR) scanners that allow access to the patient during image acquisition and thus permit MR-guided biopsies have been introduced. A variety of MR-compatible biopsy needles and a prototype coaxial drill system, powered either by hand or an optional motor, are presently available for sampling skeletal lesions. In a small study population of 28 patients in our hospital who required a biopsy of a skeletal lesion, all but five biopsy procedures could be completed within the MR unit. In one patient who required a transpedicular approach to a lumbar vertebra, we decided to switch to computed tomography (CT) guidance. Four patients needed general anesthesia, which is currently not available in our interventional MR suite. Those procedures were also performed under CT guidance. In 18 of the 23 MR-guided cases, the samples were sufficient and the histopathologic diagnoses were confirmed by surgery or the clinical course. Three biopsies contained an adequate volume in the sample, but the contents were either unrepresentative of the final pathology or distorted beyond recognition by the biopsy drill. Two others revealed insufficient material. No procedural complications occurred. Percutaneous biopsy of skeletal lesions performed under MR guidance seems to be a safe procedure and reasonably accurate given the fact that it is still in an early stage of development. MR imaging may be used as an alternative to CT, but its role vis-vis CT has yet to be ascertained.