Translating 3D stack-of-spirals lung water MRI from 0.55T to 1.5T

Motivation: Our recently developed 0.55T MRI sequence to measure lung water dynamics has clinical utility in the evaluation of heart failure, but cardiac MRI is more widely performed at 1.5T. Goal(s): To translate a 3D stack-of-spirals lung water MRI sequence from 0.55T to 1.5T. Approach: We optimized sequence parameters through Bloch equation simulation, phantom experiments, and in vivo imaging in 10 healthy volunteers, acquired at two different centers. Results: The sequence parameters TE/TR/FA/readout duration=0.70ms/9.0ms/1°/1.5ms at 1.5T yielded proton density weighted images with apparent SNR 13.5±2.2, limited image blur, and quantified a lung water density 20±3.2%. Impact: Lung water quantification has emerged as a promising method to monitor and predict outcomes in heart failure. Translation of a lung water MRI sequence from 0.55T to 1.5T enables a more widespread adoption of this tool.