Correction of Errors in PRFS Thermometry Due to Heat Induced Susceptibility Changes of Fat

Paul Baron¹, Roel Deckers¹, Sara M. Sprinkhuizen¹, Chris J. G. Bakker¹, L. W. Bartels¹

The aim was to correct susceptibility errors in Proton Resonance Frequency Shift (PRFS)-based thermometry caused by the heating of fat. The feasibility was shown in an oil/water phantom, cooled from 60 to 35C . The susceptibility change in oil was calculated using T1-thermometry. The resulting field disturbance was calculated using the Fourier transform technique. The corrected PRFS change was calculated by subtracting the field disturbance from the measured PRFS change. The temperature was monitored with fiber optic probes. For two locations measured for the whole temperature range the mean absolute PRFS temperature error decreased by about one third when corrected.