All MR experiments in this study were conducted at a 3 T scanner (MAGNETOM Prisma, Siemens Healthineers, Erlangen, Germany) using the conventional dual‐drive body coil as the transmitter and a 20‐channel head/neck coil (Head/Neck 20, Siemens Healthineers) as the receiver. All temperature measurements were performed using fiber optic temperature probes during high‐power 3D turbo‐spin echo (TSE) scans. The temperature data was acquired with a 0.5 s temporal resolution.
In the calibration phase, a TSE pulse sequence was used with FA = 150°, TR/TE = 300 ms/103 ms, in‐plane resolution = 0.5 mm, slice thickness = 1.25 mm, acquisition matrix = 512 × 512, TSE‐factor 15, no. of averages = 1, and pixel bandwidth = 220 Hz/pixel to heat the implant with quadrature excitation of the body coil (total average input power of 20 W). As shown in Figure2B , a temperature probe was placed carefully around the contact C1 of the electrode at a distance of 2.5 mm.
In the calibration phase, a TSE pulse sequence was used with FA = 150°, TR/TE = 300 ms/103 ms, in‐plane resolution = 0.5 mm, slice thickness = 1.25 mm, acquisition matrix = 512 × 512, TSE‐factor 15, no. of averages = 1, and pixel bandwidth = 220 Hz/pixel to heat the implant with quadrature excitation of the body coil (total average input power of 20 W). As shown in Figure