Affiliation:
1. Sunnybrook Research Institute – Physical Sciences Platform Toronto ON Canada
2. Department of Electrical and Computer Engineering McMaster University Hamilton ON Canada
3. Department of Medical Biophysics University of Toronto Toronto ON Canada
Abstract
AbstractBackgroundParallel radiofrequency transmission (pTx) remains a promising technology for addressing high‐field magnetic resonance imaging (MRI) challenges, particularly regarding the safety of patients with implanted deep brain stimulation (DBS) devices. Radiofrequency (RF) shim optimization methods utilizing pTx technology have shown the potential to minimize induced RF heating effects at the electrode tips of DBS devices at 3 T.PurposeResearch pTx system implementations often involve the combination of custom and commercial hardware that are integrated onto an existing MRI system. As a result, system characterization is important to ensure implant‐friendly safe imaging conditions are satisfied for the operating range of the hardware.MethodsUtilizing electromagnetic and thermal simulations, the impact of system uncertainty is studied for the proposed 4‐ and 8‐channel pTx system setup and its associated “safe mode” for DBS applications.ResultsElectromagnetic simulations indicated that instrumentation errors can affect the overall electric field strength experienced at the DBS lead tip, and a worst‐case system uncertainty analysis predicted temperature elevations of +1.5°C in the 4‐channel setup and +0.9°C in the 8‐channel setup.ConclusionsIn conclusion, system uncertainty can impact the precision of pTx RF inputs which in the worst‐case, may lead to an unsafe imaging scenario and the proposed 8‐channel setup may provide more robustness and thus, safer conditions for MRI of DBS patients.