Fig 1.

A, T1-weighted coronal image shows the five temporal gyri: superior temporal gyrus (A), middle temporal gyrus (B), inferior temporal gyrus (C), fusiform gyrus (D), parahippocampal gyrus (E), and hippocampus (F). The red triangle (G) defines the region of classification for determining the volume of the temporal stem, which represents the trunk of the white matter projections of the temporal lobe in the coronal plane.

B, Coregistered T2-weighted image.

C, Edited segmented image from the T1- and T2-weighted images depicts gray matter in gray, white matter in white, and CSF in blue. The Volume Render Module and region-of-interest feature in ANALYZE (54, 55) were used to identify gyral boundaries, defined by each sulcus.

D, Three-dimensional reconstruction of this subject’s brain depicts a lateral view showing the region where gyral quantification occurred (green) and the temporal pole (yellow). Anterior to the coronal sections in A and B, where the temporal horn is no longer definable, was the landmark to begin measuring the temporal pole. The red triangle (G) in A defines the region of classification for determining the volume of the temporal stem. The mesial vertical boundary was defined by connecting the inner extension of the sylvian fissure to the most lateral aspect of the temporal horn, triangulated with the gray matter extension at the innermost point of the superior temporal sulcus. CSF boundaries were defined by CSF segmented pixels in the region bounded by the inferior frontal lobe and the superior temporal gyrus for the sylvian fissure; between the superior and inferior temporal gyri for the middle temporal sulcus; between the inferior and fusiform for the inferior temporal sulcus; and the rhinal sulcus between the fusiform and parahippocampal gyrus.