Comparison of duplex and nonduplex transcranial Doppler ultrasonography.
Transcranial Doppler ultrasonography is essential in the management of children with sickle cell anemia and is a valuable adjunct to the evaluation of a variety of intracranial pathologies in children and adults, including vasoconstriction caused by subarachnoid hemorrhage, demonstration of major intracranial vessel stenoses or occlusion, determination of brain death, demonstration of the nidus of arteriovascular malformations, and assessment of cerebral hemodynamics after trauma, stroke, or migraine. There are 2 types of transcranial Doppler equipment currently available: nonduplex (nonimaging) and duplex (imaging). The purpose of this review is to compare and contrast the clinically relevant differences between these 2 types of equipment.