Impact of Excess AIMD Lead Winding Near the Implantable Pulse Generator on MRI RF-Induced Heating

To understand the impact of lead winding near the Implantable Pulse Generator (IPG) on Active Implantable Medical Device (AIMD) transfer function (TF) models and RF-induced heating inside human body during Magnetic Resonance Imaging (MRI) scan at 1.5 T for safety considerations.

Three AIMD systems: a Cardiac Rhythm Management (CRM), a Spinal Cord Stimulator (SCS), and a Deep Brain Stimulator (DBS) are used in the study. TF models were developed for various winding configurations and validated in accordance with ISO/TS 10974. Heating predictions using human body models were evaluated inside three anatomical human models.

Results reveal significant variations in TF robustness and heating behavior across different systems and winding configurations. The CRM system demonstrated the highest TF robustness, whereas the SCS system showed the maximum variation. It was observed that the RF-induced heating was lower for CRM and DBS systems with winding, whereas for the SCS system, the RF-induced heating would be higher with different winding patterns. These findings emphasize the need for tailored MRI safety assessments for AIMDs, particularly for systems with thin lead insulation.

The study highlights the importance of considering AIMD lead properties and patient-specific winding configurations in MRI safety evaluation.