Transcranial Doppler and Duplex Scanning
Transcranial Doppler ultrasound (TCD) has been used in some hospitals in Australia for more than 15 years and, in the last 5 years, most of the commercially available duplex scanners are supplied with transcranial colour-coded duplex (TCCD) capability. In addition, there have been significant advances in TCD technology, such as power M-mode, making TCD easier to use. Over the same period, the role of transcranial ultrasound has changed from being a research tool, to providing important diagnostic information in the clinical management of patients with cerebrovascular disorders. In addition, we are on the threshold of using TCD as a therapy in patients with acute ischaemic stroke. Some of the clinical applications of TCD/TCCD include diagnosis of vasospasm in patients with subarachnoid haemorrhage, assessment of intracranial and extracranial stenosis, diagnosis of brain death, monitoring for microembolic signals, and ultrasound-enhanced thrombolysis. All acute care hospitals providing a stroke service should have transcranial ultrasound capability.