The glabella-inion line as a baseline for CT scanning of the brain.

The optimal position of the head for CT scanning of the brain is discussed according to the statistical data of roentgencraniometry. The glabella-inion (GI) line was shown to be parallel to the frontal-occipital pole (FO) line which was substituted for a line joining the deepest gyral impressions in frontal and occipital parts of the cranial cavity. On the other hand, Reid's baseline and the canthomeatal (CM) line intersected the GI line at various angles from person to person. There was a significant difference between each average inclination angle of males and females. Regarding using either Reid's or the CM line for a baseline, it should be noted that the brains were scanned in almost random direction. Therefore it may be convenient to apply the GI line for comparing the findings between individuals, and for correlating them to the anatomical diagnosis.