Lesion segmentation is a mandatory step in Multiple Sclerosis (MS) patients diagnosis. A lot of different semi-automatic or automatic methods are available in the litterature. However these methodes are not always validated with the same criteria. Consequently, to compare these methods can be a fastiduous task. LSC aim to compute statistics between a segmentation of reference and a "tested segmentation". The segmentation of reference (SegRef) can be obtain thanks to an expert using the Lesion Segmentation Editor. The tested segmentation (SegTes) can be the one obtain by an automatic method.