Feasibility of fast all-systolic volumetric MR thermometry with integrated Active Tracking

Motivation: Cardiac MR-thermometry is a promising approach for the guidance of cardiac ablation procedures. It acquires multiple contiguous slices per heartbeat, leading to acquisitions at different cardiac phases limiting 3D lesion assessment. Goal(s): A novel fast single-phase volumetric CMR-thermometry sequence is presented which allows multiple slices to be acquired in the quiescent phase of systole or diastole. Approach: Active tracking was added to an SMS EPI sequence to enable prospective slice tracking. A double inversion recovery pre-pulse is introduced for dark blood and to reduce acquisition time. Results: In a pig model, the temperature stability was 0.9±1.4°C in systole and 0.8±0.8°C in diastole. Impact: This study demonstrates the feasibility of fast single-phase volumetric MR thermometry with integrated Active Tracking, which may improve the safety of the procedure and the accuracy of lesion formation.