Computed tomography of the optic nerve: part I. Normal results.

In vivo visualization of the optic nerve (ON) by computed tomography (CT) has important clinical applications, both realized and potential. An accurate CT analysis of the ON is, however, hampered by a number of technical limitations. Sinuosity and gaze-shift-related motility of the ON tend to increase the difficulties of demonstrating in a consistently satisfactory fashion this anatomical structure. Nevertheless, if rigid imaging criteria are followed, adequate visualization of the ON may be attained in the majority of patients. Simultaneous visualization of the ON and the eyeball permits establishment of a neuroocular index for clinical use.