CT identification of cortical speech areas in the human brain.

In four human left cerebral hemispheres the cortical speech areas were identified, having been marked by differential color code before transverse sectioning. The results from the anatomic dissection specimens were compared with thin CT sections in normal individuals, the CT plane being aligned to the orbitomeatal plane as an external reference, and thus closely parallel to the bicommissural plane, as an internal reference. The same cortical structures were identified in the CT sections. A strategic approach to CT examination of the cortical speech areas is formulated, based on the external-internal system of reference.