High resolution orbital computed tomography.

The latest generation CT scanners allow for spatial and contrast resolution within the orbit that has not previously been available. Utilization of these technological advances in association with appropriate techniques enables visualization of vascular and neural structures within the orbits that have not previously been emphasized in the literature. The CT scans were generated in both axial and coronal planes, using either 1 or 2 mm thick sections. All images were generated using ultrahigh resolution scanning techniques, available on the Picker 1200-SX scanner. The primary advantage of this system is the availability of secondary collimation of the X-ray beam at the detector, limiting detector aperture to only 1.3 mm. This, in association with utilization of the small focal spot and high sampling rate, aids in the visualization of divisions of the third and fifth nerves, as well as in the visualization of the sixth nerve within the orbit. Several branches of the ophthalmic artery within the orbit are also identified, including the infratrochlear and supratrochlear artery as well as the central retinal artery.