Improving the Detection of Myelin Integrity in Multiple Sclerosis Using Selective Inversion Recovery for MRI With Quantitative Magnetization Transfer.

Background: Selective inversion recovery quantitative magnetization transfer (SIR-qMT)-derived macromolecular to free water pool size ratio (PSR) and diffusion tensor imaging (DTI)-derived radial diffusivity (RD) are potential metrics for assessing myelin integrity in multiple sclerosis (MS). However, establishing their accuracy in identifying tissue injury is essential for clinical translation.

Purpose: To compare the accuracy and Cohen's effect size (ES) of PSR and RD in detecting and quantifying tissue injury in early MS.

Chronic active lesions preferentially localize in watershed territories in multiple sclerosis.

Objective: Paramagnetic rim lesions (PRLs) are a biomarker of chronic active lesions (CALs), and an important driver of neurological disability in multiple sclerosis (MS). The reason subtending some acute lesions evolvement into CALs is not known. Here we ask whether a relatively lower oxygen content is linked to CALs.

Watershed regions are more susceptible to tissue microstructural injury in multiple sclerosis.

Histopathologic studies report higher concentrations of multiple sclerosis white matter lesions in watershed areas of the brain, suggesting that areas with relatively lower oxygen levels may be more vulnerable to disease. However, it is unknown at what point in the disease course lesion predilection for watershed territories begins. Accordingly, we studied a cohort of people with newly diagnosed disease and asked whether (1) white matter lesions disproportionally localize to watershed-regions and (2) the degree of microstructural injury in watershed-lesions is more severe.

Improving the assessment of axonal injury in early multiple sclerosis.

Rationale And Objectives: Several quantitative magnetic resonance imaging (MRI) methods are available to measure tissue injury in multiple sclerosis (MS), but their pathological specificity remains limited. The multi-compartment diffusion imaging using the spherical mean technique (SMT) overcomes several technical limitations of the diffusion-weighted image signal, thus delivering metrics with increased pathological specificity. Given these premises, here we assess whether the SMT-derived apparent axonal volume (V) provides a better tissue classifier than the diffusion tensor imaging (DTI)-derived axial diffusivity (AD) in the white matter (WM) of MS brains.