A Guidewire Trajectory Generation Tool for Interventional MRI Simulations

Abstract

Significance: RF-induced heating of endovascular devices limits MRI-guided interventions, including targeted drug delivery to brain tumors. Purpose: To present a tool that rapidly generates randomized guidewire trajectories for RF heating risk assessment. Methods: A MATLAB tool models the guidewire as a spline with randomized control nodes and a fixed nominal length. As a use case, tip sSAR was estimated for 1000 trajectories using straight-wire transfer functions and 64 MHz local and body coil fields (matched B1) in the Duke phantom. Results: Length accuracy was 99.84%, and 3000 trajectories were generated in 11.5 s. Body-to-local sSAR ratios at the 50th, 95th, and 99th percentiles were 1.5, 1.6, and 2.27, but some trajectories heated more under the local coil. Conclusion: The tool enables large-sample heating assessment, and coil type alone did not reliably predict individual trajectory risk.