Extended Data Figure 3. White matter fiber tracts in fetal human brain.

Orientation-encoded diffusion tensor imaging (DTI) colormaps in the left panel (a) and the three-dimensionally reconstructed fetal white matter fibers in the right panels (b, c and d) for fetal brains at 15pcw (upper row), 16pcw (middle row) and 19pcw (lower row). The orientation-encoded DTI colormaps are in axial planes at the anterior commissure level. The red, pink, green and purple fibers in the right panels are cc in (b), cp and icp in (c), and pvf in (d), respectively. The transparent whole brain and yellow thalamus are also shown as anatomical guidance in (b), (c) and (d). The scale bars are shown in the left panel (a). The fiber name abbreviations are as follows. cc: corpus callosum; cp: cerebral peduncle; icp: inferior cerebellar peduncle; pvf: periventricular fibers (transient fibers coursing around the germinal matrix and only existing in the prenatal fetal brain).