Geometric Evaluation of Distortion Correction Methods in Diffusion MRI of the Spinal Cord

Acquiring and processing Diffusion MRI in spinal cord present inherent challenges. Differences in magnetic susceptibility between soft tissues, air and bone make the magnetic field of spinal cord non-uniform and inhomogeneous. In this context various procedures were proposed for correcting this distortion. In this work, we propose novel geometric statistics to measure the alignment of the reconstructed diffusion model with the apparent centerline of the spine. In parallel of the correlation with an anatomical T2-weighted image, we show the utility of these statistics to study and evaluate the impact of distortion correction by comparing 3 distortion correction methods from reversed gradient polarity strategy.