An Experimental Comparison for RF Heating of DBS Electrodes at 3T and 7T

Motivation: With the growing demand for MRI scans in patients with deep brain stimulation (DBS) implants, understanding SAR and RF heating around these devices is essential for safety and improved scan protocols. Goal(s): To compare the RF heating around DBS electrodes at 3T and 7T. Approach: Bilateral DBS were fixed in the skull cavity of an anthropomorphic head phantom. Temperature-based SAR estimation quasi-static electric field and thermal simulations were conducted at 7T and 3T. Results: The mean of the 1 g-averaged SAR normalized to B1+RMS2at 7T, on average, was 5.6 times lower than at 3T. Impact: Comparing 1 g-averaged SAR (normalized to B1+RMS2) around DBS electrodes at 3T and 7T suggested that 7T MRI may pose less heating risk and provided a compelling case to expand the potential of imaging DBS patients at higher-field MRI.