Design and Validation of a Novel MR-Compatible Sensor for Respiratory Motion Modeling and Correction

GOAL: A novel magnetic resonance (MR) compatible accelerometer for respiratory motion sensing (MARMOT) is developed as a surrogate of the vendors' pneumatic belts. We aim to model and correct respiratory motion for free-breathing thoracic-abdominal MR imaging and to simplify patient installation. METHODS: MR compatibility of MARMOT sensors was assessed in phantoms and its motion modeling/correction efficacy was demonstrated on 21 subjects at 3 T. Respiration was modeled and predicted from MARMOT sensors and pneumatic belts, based on real-time images and a regression method. The sensor accuracy was validated by comparing motion errors in the liver/kidney. Sensor data were also exploited as inputs for motion-compensated reconstruction of free-breathing cardiac cine MR images. Multiple and single sensor placement strategies were compared. RESULTS: ), with all tested configurations. Expert readings revealed multiple MARMOT sensors were the best (p < 0.03) and the single MARMOT sensor was similar to the belts (nonsignificant in two of the three readers). CONCLUSION: The proposed sensor can model and predict respiratory motion with sufficient accuracy to allow free-breathing MR imaging strategy. SIGNIFICANCE: It provides an alternative sensor solution for the respiratory motion problem during MR imaging and may improve the convenience of patient setup.