Reproducibility and Evolution of Diffusion MRI Measurements within the Cervical Spinal Cord in Multiple Sclerosis

TL;DR

This study assesses the reproducibility of diffusion MRI measurements in the cervical spinal cord of healthy individuals and tracks disease progression in MS patients, aiming to clarify the clinical-radiological paradox.

Contribution

It introduces a test-retest protocol for diffusion MRI in the cervical spine and quantifies MS pathology evolution over one year using advanced diffusion models.

Findings

High reproducibility of diffusion MRI metrics in healthy volunteers

Quantitative evidence of spinal cord damage progression in MS patients

Diffusion metrics correlate with disease severity and progression

Abstract

In Multiple Sclerosis (MS), there is a large discrepancy between the clinical observations and how the pathology is exhibited on brain images, this is known as the clinical-radiological paradox (CRP). One of the hypotheses is that the clinical deficit may be more related to the spinal cord damage than the number or location of lesions in the brain. Therefore, investigating how the spinal cord is damaged becomes an acute challenge to better understand and overcome the CRP. Diffusion MRI is known to provide quantitative figures of neuronal degeneration and axonal loss, in the brain as well as in the spinal cord. In this paper, we propose to investigate how diffusion MRI metrics vary in the different cervical regions with the progression of the disease. We first study the reproducibility of diffusion MRI on healthy volunteers with a test-retest procedure using both standard diffusion tensor imaging (DTI) and multi-compartment Ball-and-Stick models. Then, based on the test re-test quantitative calibration, we provide quantitative figures of pathology evolution between M0 and M12 in the cervical spine on a set of 31 MS patients, exhibiting how the pathology damage spans in the cervical spinal cord.