In vivo assessment of multiple sclerosis pathology: The role of neuroimaging techniques

Although the correlations between magnetic resonance imaging (MRI) findings and long-term disease evolution range from poor. to moderate': conventional pre- and post-contrast MRI provides sensitive and, reliable measures to monitor multiple sclerosis (MS) activity over time. The application of non-conventional techniques, such as magnetization transfer imaging (MTI), proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI), can increase the pathological specificity of MRI findings and, as a consequence, improve the relationship with the clinical evolution of the disease. These techniques also enable us to quantify the subtle abnormalities occuring in the so-called nor-mal-appearing white matter, thus allowing to achieve a more accurate assessment of MS burden. Some of the aforementioned techniques have already shown their value for assessing MS dynamics. whereas other still need to go through a more complete validation process prior to any extensive clinical application in MS. The use of multiparametric MRI approaches including both conventional techniques and new methods able to assess the macro- and microscopic disease burden and to characterize the individual lesion intrinsic nature, should improve our ability, to study in vivo the pathology of MS.