YASARGIL ANEURYSM CLIPS - EVALUATION OF INTERACTIONS WITH A 1.5-T MR SYSTEM

PURPOSE: To evaluate the magnetic field interactions with Yasargil ane urysm clips exposed to a 1.5-T MR system. MATERIALS AND METHODS: Sixte en Yasargil aneurysm clips made with Phynox (10 clips returned to the manufacturer due to suspected magnetic field interactions and six clip s obtained from the manufacturer in sterile packages) were tested for magnetic field interaction at 1.5 T by using techniques to assess magn etic field-induced translational (deflection angle test) and torque (c hanges in alignment or rotation) forces. RESULTS: None of the aneurysm clips demonstrated magnetic field interactions; that is, deflection a ngles were zero and there were no changes in alignment or evidence of rotational forces present. CONCLUSION: It is safe to perform MR proced ures at 1.5 T or less in patients with Yasargil aneurysm clips made wi th nonferromagnetic material.