INTERACTIVE MR-GUIDED BIOPSY IN AN OPEN-CONFIGURATION MR-IMAGING SYSTEM

PURPOSE: To describe new techniques for percutaneous biopsy with use o f an open-configuration magnetic resonance (MR) imaging system with in tegrated frameless stereotaxic guidance tools. MATERIALS AND METHODS: In 28 patients, biopsy was performed in which the image plane was inte ractively controlled by the position of a hand-held probe attached to the biopsy needle. An icon integrated into the image was used to guide needle advancement in three planes orthogonal to the needle. In vitro measurements of spatial accuracy were also performed. RESULTS: Diagno stic tissue was retrieved in 25 of 28 patients. The system was most ac curate near the isocenter with a maximum measured error of 3.1 mm with in a sphere of radius 2.5 cm about the isocenter. CONCLUSION: MR-guide d biopsy with a frameless stereotaxic technique is safe and accurate. Image feedback is near real time, and the procedure is interactive. Th ese techniques may be used to perform MR-guided biopsies and to place probes for MR-guided therapies.