Transcranial Doppler series part IV: case studies.

Transcranial Doppler (TCD) is considered one of the most difficult ultrasound studies to perform. Knowledge of cerebral hemodynamics is essential to the interpretation of the TCD study. The most common uses for TCD are the evaluation for vasospasm after subarachnoid hemorrhage and for sickle cell vasculopathy. Other uses are the detection of vessel narrowing or occlusion, collateral flow secondary to internal carotid artery occlusion, arteriovenous malformations, and to confirm cerebral circulatory arrest. Case studies are presented to demonstrate the hemodynamic parameters that are used to interpret the TCD study.