Figure 3. Comparative tractography study between the two hemispheres in the five cases of meningioma.

Cases M1, M2 and M5: Estimation of the fiber tracts between the main target and the dilated region homologous to the tumor in the healthy hemisphere; comparison with the contralateral lesioned architecture. In the case of M1, the ascending fibers from the thalamus to cerebral cortex and the descending fibers from the fronto-parietal cortex to subcortical nuclei and spinal cord were splayed into different branches in the lesioned hemisphere. The same alteration pattern was identified in the cortico-ponto-cerebellar tract reconstructed in patient M2, as a result of the tumor mass. The fiber tracts that leave the internal capsule ventrally and continue into the cerebral peduncles, pons and piramidal tract in the pathological hemispehere of patient M5 resulted bulky displaced, in relation to the contralateral WM architecture. Cases M3 and M4: estimation of the fiber tracts between the two target regions in the healthy hemisphere, and comparison with the contralateral lesioned architecture. The lesion mass changed the location and organization of the inferior fronto-occipital fasciculus tracked in the healthy hemisphere in both patients M3 and M4.