Intracranial and orbital doppler in cerebrovascular disease1

Abstract

Color doppler imaging (CDI) is a diagnostic tool that allows non-invasive evaluation of the orbital and intra-cranial structures. It operates by the doppler principle, which is detecting changes in the frequency of sound that is reflected from flowing blood, allowing estimation of flow velocity. CDI has been used in the diagnosis and follow up of ophthalmic conditions such as central retinal artery occlusion, central retinal vein occlusion, arteritic and non-arteritic ischemic optic neuropathy and the ocular ischemic syndrome. In addition, orbital conditions like varices can be evaluated. Transcranial doppler has been used to assess strokes and arteriovascular malformations of the brain. The main limitation of CDI is that it provides information about velocity and not flow. Despite this, it remains a valuable tool to diagnose ocular and intracranial conditions characterized by ischemia or abnormal blood flow.