The ventricular size on computed tomography.

Deriving a ventriculocranial index for the evaluation of ventricular size from a standard transverse plane image can lead to an erroneously small estimate of ventricular size due to partial volume averaging. Coronal plane imaging largely eliminates this problem. The index can then be derived either from the video image or the digital printout. There appears to be less error in measurements derived from the image than in measurements derived from the 64 X 64 printout, provided the image is photographed at large window widths of 2,000 Delta units or more.