Practical sampling strategies for volumetric cardiac real-time MRI using stack-of-spirals at 0.55T

Motivation: Volumetric real-time MRI is desirable to accurately characterize beat-to-beat cardiac function in patients with arrythmia or heart failure. Goal(s): To identify practical data sampling strategies for volumetric real-time MRI and evaluate cardiac volume measurements against gated reference scans. Approach: We focus on stack-of-spirals bSSFP at 0.55T. We use simulations and in-vivo experiments to compare three sampling strategies that minimize eddy currents. Results: A Gaussian distribution of the stack-of-spirals was found to provide the best real-time image quality and most accurate LV volumes, with under-estimation of end-diastolic volume by 7.44% and over-estimation of end-systolic volume by 18.33%. Impact: Beat-to-beat cardiac function is important to measure in the context of arrhythmia, cardiac stress testing and in interventional MRI, where real-time volumetric coverage will facilitate assessment and monitoring of cardiac function.