Coupled modeling and experimental investigation of RF-induced heating near ablation catheters under 1.5T MRI

RF-induced heating of ablation catheters under 1.5T magnetic resonance image (MRI) is studied using combined computational modeling and bench testing. The transfer function of ablation catheters are measured experimentally without simplification. A high-resolution anatomical human model was then used to simulate clinical MRI RF exposure environment. The upper limit of the temperature rise was calculated around two types of catheters, namely a single wire catheter and twin wire catheter. Four different insertion depths between 17.5 cm to 70 cm inside human body model were evaluated, simulating procedure for brain or cardiac ablation. A temperature hotspot was observed around the tip of the catheter with an estimated maximum temperature rise higher than 100 o C for the single lead catheter and around 94 o C for twin lead catheter, with patient landmark varying from −200 mm to 1000 mm with respect to human eye-center. Three experiments were conducted in a standard phantom to validate this coupled method and it showed a good agreement between direct measurements and predicted heating results.