The normal computed tomogram.

Abstract

ATISFACTORY S interpretation of computed tomograms (CT) of the brain requires a solid foundation in conventional radiographic anatomy, ie, familiarity with the appearance of the ventricles and subarachnoid spaces as seen during pneumoencephalography, and of the vascular anatomy of the brain as demonstrated by arteriography. The excellent radioanatomic studies of the subarachnoid cisterns by Liliequist” and the introduction of the concept of axial tomography during pneumoencephalography by Di Chiro’ have described much of the anatomy that is now so important in CT scans of the brain. Radiographic anatomy of the cerebral circulation has been well described,14,‘71’9 and several excellent atlases of CT anatomy have recently become available.4”2,‘8 There is much normal variation in cerebral anatomy from patient to patient. While we see only one surface of the cut brain section, the CT image averages the densities in a section 1.3 cm thick. Thus, there is incomplete agreement between the structures seen on the same pathologic and CT sections. A composite of several CT sections is often required to demonstrate the anatomy seen in each brain section. Our primary aim is to demonstrate as many of the brain structures as possible by the CT examination.