798 Fig. 2 Lesion detection. From left to right, hyperintense FLAIR lesions, hypointense FLAIR lesions, and hyperintense DWI lesions were pre-detected using an unsupervised 3D segmentation algorithm after skull removal, and manually validated prior to submission to readers Fig. 3 Brain parenchyma detection. Brain parenchyma contours (in red) was pre- detected using a 3D segmentation algorithm on 3DT1 images by 3D deformable registration of a brain atlas, after skull removal, and manually validated prior to submission to the readers. Interhemispheric plane is shown in yellow J Neurol (2011) 258:795–803 atrophy with more accuracy on the contra-lateral hemi- sphere, as the initial infarct and surrounding tissue changes did not affect this measurement. The Jacobian integration, a quantitative technique based on a 3D non-rigid matching of baseline and follow-up MRI examinations [13] was used for the assessment of the longitudinal brain volume changes. As a registration-based technique, it requires less manual interactions with respect to a segmentation-based technique or the boundary shift integral [14, 15] and allows the detection of small brain volume changes [16]. The hippocampal volume was deﬁned as the complex interfolded layers of the cornu ammonis (grey matter), the dentate gyrus (grey matter), the alveus (white matter), the subiculum (grey matter) and the ﬁmbria (white matter). The hippocampal–amygdalar boundary was identiﬁed with reference to the temporal horn of the ventricles and, where possible, to the presence of the alveus. Hippocampal 123