Diagnostic Values of Transcranial Doppler Ultrasound Detecting High-grade Carotid Stenosis

Choi, Sun Ah; Sohn, Young Ho

Abstract

BACKGROUND: Transcranial Doppler Ultrasonography (TCD) is a non-invasive and easily applicable method to evaluate cerebral hemodynamics. The objective of this study is to evaluate the diagnostic value of TCD parameters detecting high-grade extracranial carotid stenosis.
METHODS
The subjects were 17 patients who showed high-grade carotid stenosis (>75%) or occlusion on cerebral digital subtraction angiography (DSA) and 18 patients whose DSA were normal. TCD parameters were reversed ophthalmic artery flow (OR), reversed anterior cerebral arterial (ACA) flow (AR), increased flow velocity of contralateral ACA (>80cm/sec; CA), decreased flow velocity of ipsilateral MCA (<30cm/sec; IM), absence of ICA flow at siphon(IS), reduced flow acceleration (<280cm/sec2; FA) and pulsatility index (<0.5; PI) of MCA.
RESULTS
The sensitivity of each parameter was 23.5% for OR, 47% for AR, 58.8% for CA, 5.9% for IM, 23.5% for IS, 70.6% for FA and 11.8% for PI, while their specificity was 100% in all parameters, except IS, 83.3%. When AR, CA and FA are combined, the sensitivity increased up to 86.7%.
CONCLUSIONS
Reduced flow acceleration of MCA and parameters related with collateral flow through the anterior communicating artery were proved to be more sensitive TCD parameters detecting high-grade extracranial carotid stenosis or occulsion than other parameters. Thus patients with abnormal TCD measurements of these parameters may need further evaluation for carotid disease.