Brain White Matter Pathological Comparison in MS Relapsing-Remitting Patients, Clinically Isolated Syndrome Patients and Normal Subjects Using Quantitative Magnetization Transfer Imaging

The aim of this study is to investigate abnormalities and characterize pathologic changes associated with demyelination in the brain tissue of patients with multiple sclerosis (MS). In this method, magnetization transfer parameters such as magnetization transfer ratio (MTR), magnetization transfer rate (K-sat) and native relaxation time of brain tissue with and without saturating pulse were determined (T1(free), T1(sat)). Measurements were performed with both of segmentation regional measurements. It had been shown that individual valuables contributing to magnetization transfer process can be provide further insight into the mechanisms of myelin destruction in multiple sclerosis disease. Conventional MR imaging protocols such as T1-weighted, T2-weighted, T2-FLAIR as well as MT-3DSPGR images were performed on ten MS patients and ten normal subjects. White matter and lesion masks were segmented from T2-weighted images and superimposed on MT parameter maps using FSL software. MTI parameters of lesions and normal appearing white matter (NAWM) were analyzed in comparison with those of normal volunteers. Group mean T1 relaxation times throughout NAWM increased when going from control subjects to CIS to RR MS. In the RR and CIS MS groups, the T1 increases compared with control subjects were significant throughout the NAWM, without apparent preference for specific brain regions. Significant reduction in NAWM-MTI parameters of MS patients compared to normal subjects shows that pathological changes occur outside visible lesions on conventional MR images among patients with multiple sclerosis. Quantitative MT imaging can help to evaluate the extent of global damage in the brain tissue. The results showed that at a group level there is widespread involvement of WM throughout the brain in CIS MS and especially in RRMS, where a significant T1 increase was found in 15.58% of WM voxels (Normal < RR).