Figure 2.

(a) A slice of T1-weighted MRI data; (b) the slice in (a) has been segmented into three types of tissues, i.e., white matter (dark), gray matter (gray), and non-brain fluid (white); (c) FA map of the same slice; (d) cortical triangular mesh surface reconstructed on the boundary between brain tissue (white matter and gray matter) and non-brain fluid in (b). Arrows indicate the radial directions; (e) a slice from a 21 pcw fetal brain sectioned in the coronal plane and stained for Nissl; (f) An enlarged view of the regions highlighted by the blue frame in (e). The slice is cut into 128-by-128 pixel image blocks (black chessboard), on which methods in Arteta et al. (2012) are adopted to identify neurons. White curves are manually depicted cortical plate boundaries. Columns within the cortical plate and perpendicular to the boundaries are illustrated by dense red bars. The yellow bars illustrate some example columns; (g) an enlarged illustration of columns in the region highlighted by the red frame in (f); (h) one image block in (f). Purple blobs are neuronal cells; (i) Neuron identification results of the image block in (h). Green/red curves indicate extremal neuron boundaries. Yellow dots indicate neuron centers; (j) an enlarged view of neuron identification results in the orange color frame in (i).