Different sets of criteria are currently used for the diagnosis of multiple sclerosis (MS). Some are based on clinical features, while others are related to imaging findings. Among the image processing systems, specific criteria include spatial dissemination of lesions in one image or their temporal dissemination in images acquired at different time points. In addition, the evolution of the lesion load can be used to evaluate treatment efficiency in MS clinical research. Consequently, obtaining a precise segmentation of the MS lesion appears to be crucial. In the literature, a number of semi-automated or completely automated approaches have been proposed enabling a reduction of the inter- and intra-expert variability for manual delineations. A comprehensive state-of-the-art classification of the most representative systems is presented here.