Analysis on Echo Placement for Multi-echo Proton Resonance Frequency Shift Thermometry

Abstract

Proton resonance frequency shift based MR thermometry is widely used to non-invasively monitor thermal therapies in vivo. Multi-echo gradient-echo sequences are being studied to increase the effective temperature to noise ratio, however, choosing the optimal echo-times is non-trivial. We developed an optimization framework based on measurement noise models to compute the optimal echo placement for schemes that either correct or do not correct for the conductivity bias. In a 4-echo phantom experiment, we demonstrated a reduction in the noise standard deviation of 22% when comparing optimal to equidistant echo placements.