Impact of Patient Postures on the RF-Induced Heating for the Active Implantable Medical Device (AIMD) at 1.5T MRI

This article explores the influence of patient postures on radiofrequency induced heating in active implantable medical devices (AIMDs) within a 1.5T magnetic resonance imaging system. Employing the transfer function method, the study assesses RF-induced heating for AIMDs in four different postures. Three AIMD types deep brain stimulation (DBS), cardiac rhythm management (CRM), and sacral neuromodulation (SNM)] are studied across three human models (Duke, Ella, and Fats) at four imaging landmarks under two RF exposure levels: B
₁
+ and specific absorption rate (SAR) restrictions. When comparing temperature rises observed in various postures to those obtained from the typical/standard posture, it was noted that temperature rises can vary significantly. Specifically, temperature rises were found to have variations of up to 82% and 96% for prone and supine arm loop postures, respectively, while remaining within 27% for leg and trunk arm loop postures. Across DBS, CRM, and SNM systems, averaged temperature rises can vary up to 96%, 96%, and 89%, respectively. Noteworthy landmark-specific variations are observed, with changes of up to 43%, 33%, 95%, and 96% for head, cardiac, abdomen, and hip scans. The study underscores the significant impact of patient posture on AIMD heating, emphasizing the necessity for evaluations under diverse conditions.