Fig. 4.

Fetal and postnatal corpus callosum segmentation in a boy (case 2) with periventricular leukomalacia and cortical dysplasia. a–e Age 24+2 gestational weeks. a Coronal T2-weighted (TR/TE 10,653/140 ms, flip angle 90°) MR image. b Sagittal T2-weighted image. c Axial T2-weighted image of the fetal brain. d Overlay of the fiber tracts of the corpus callosum on a sagittal T2-weighted image. e The rostrum and body of the corpus callosum are not well visualized, while the genu and splenium are identifiable on sagittal diffusion tensor imaging (DTI) of the corpus callosum in the fetal brain. f–j Age 2 years. f Coronal T2-weighted (TR/TE 4,000/90 ms, flip angle 90°) MR image of the brain shows asymmetrical, right greater than left, periventricular T2 prolongation (arrowheads), compatible with white matter injury. g Sagittal T2-weighted image of the postnatal brain shows an intact corpus callosum. h Axial T2-weighted image. i Segmented sagittal view of the callosal fiber tracts overlaid on a sagittal T2-weighted image of the postnatal brain appears fully intact. j The rostrum, genu, body and splenium are identifiable on this sagittal DTI of the corpus callosum segmentation. TE echo time, TR repetition time