  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.

Image and Video Processing;Medical Physics