The Role of Transcranial Doppler in Cerebral Vasospasm: A Literature Review.

Transcranial Doppler ultrasonography (TCD) is a noninvasive technique used to detect vasospasms following a subarachnoid hemorrhage. While the gold standard to evaluate vasospasms is angiography, this technique is invasive and poses additional risks as compared to TCD. TCD is performed by insonating circle of Willis arteries to measure cerebral flow velocity. TCD allows dynamic monitoring of CBF-V and vessel pulsatility, with a high temporal resolution. It is relatively inexpensive, repeatable, and portable; however, the performance of TCD is highly operator dependent and can be difficult, especially with inadequate acoustic windows. This review summarizes the use of transcranial Doppler ultrasonography (TCD) for the assessment of cerebral vasospasm.