The Orbits

Abstract

The application of computerised tomography to orbital diagnosis was first evaluated by Ambrose et al. (1974) and by Gawler et al. (1974) using the original 80 × 80 matrix system, and subsequently the 160 × 160 matrix. Since that date, numerous publications have appeared detailing the technique for orbital scanning and recording the findings in specific pathological conditions such as tumours, inflammatory processes and dysthyroid exophthalmos. The presence of fat in the intraconal space, acting as a natural contrast medium, has made CT a very rewarding exercise in orbital diagnosis. It is now the principal method of investigation of patients presenting with unilateral exophthalmos, and suspected intra-orbital space-occupying lesions, after plain x-ray examination of the skull. Other modalities — ultrasound, orbital venography, carotid angiography—are ancillary to it.