Aneurysm clips: Evaluation of magnetic field interactions with an 8.0 T MR system

Abstract

This study was conducted to evaluate magnetic field interactions for aneurysm clips exposed to an 8.0 T magnetic resonance (MR) system. Twenty-six different aneurysm clips were tested for magnetic field translational attraction (deflection angle test) and torque (qualitative assessment method) using previously described techniques. Six of the specific aneurysm clips (ie, type, model, blade length) made from stainless steel alloy (Perneczky) and Phynox (Yasargil, models FE 748 and FE 750) displayed deflection angles above 45°and torque measurements of +4, indicating that these aneurysm clips may be unsafe for patients or individuals in an 8.0 T MR environment. The specific aneurysm clips (ie, type, model, blade length) made from commercially pure titanium (Spetzler), Elgiloy (Sugita), titanium alloy {Yasargil, model FE 750T), and MP35N (Sundt) displayed deflection angles less than 45°and torque that ranged from +1 to +4. Accordingly, these aneurysm clips are likely to be safe for patients or individuals exposed to an 8.0 T MR system. Depending on the actual dimensions and mass, an aneurysm clip made from Elgiloy may or may not be acceptable for a patient or individual in the 8.0 T MR environment. (C) 2000 Wiley-Liss, Inc.