Using a Simple Thermal Model to Correct Errors in PRFS MR Thermometry Due to Heat-Induced Tissue Susceptibility Changes

Paul Baron¹, Roel Deckers¹, Martijn de Greef¹, Job G. Bouwman¹, Chris J.G. Bakker¹, Lambertus W. Bartels¹

During MR-guided high intensity focused ultrasound (MR-HIFU) ablation of fat-containing tissues like the human breast or liver, heat induced susceptibility changes may give rise to local field disturbances, leading to errors in PRFS thermometry of the water-based tissues. A correction method is presented that combines the initial uncorrected measured temperature change with a thermal model to estimate the field disturbance and thus correct for these errors. The feasibility is shown in a porcine adipose tissue and ethylene glycol gel phantom. The maximum temperature error decreased from 3C before correction to less than 1C after the correction.