Color Velocity Imaging Quantification in the Detection of Intracranial Collateral Flow

Abstract

Background and Purpose-The development of intracranial collateral circulation is associated with a lower risk of stroke.A noninvasive technique that can reliably detect the presence of intracranial collaterals would be a valuable factor in the assessment of risk in patients with occlusive cerebrovascular disease. Methods-Color velocity imaging quantification was used to measure the blood flow volume of the common carotid and vertebral arteries in 40 patients with carotid occlusive disease. The blood flow volumes in these arteries were correlated with angiographic evidence of collaterals to establish the best cutoffs for detecting intracranial collateral circulation. Results-A blood flow volume of either Ն370 mL/min in the common carotid artery or Ն120 mL/min in the vertebral artery was indicative of the presence of intracranial collaterals. The sensitivity and specificity for the common carotid artery were 92.3% [95% confidence interval (CI), 62.1 to 99.6] and 92.1% (95% CI, 77.5 to 97.9), respectively. The sensitivity and specificity for the vertebral artery were 75.0% (95% CI, 35.6 to 95.5) and 87.5% (95% CI, 66.5 to 96.7), respectively. Conclusions-Color velocity imaging quantification offers a noninvasive, accurate method for detecting the presence of intracranial collateral circulation and quantifying its magnitude. This technique would be a useful adjunct in screening or continuous monitoring of patients with severe carotid occlusive disease.

Compensatory patterns of collateral flow in stroke patients with unilateral and bilateral carotid stenosis

“…Color velocity imaging quantification (CVIQ) ultrasound has been proved to be a noninvasive technique that can reveal extracranial arterial blood flow volume, which is an indicator of cerebral perfusion [ 8 – 12 ]. Our previous studies demonstrated that poststroke extracranial arterial blood flow volume estimated by CVIQ is an independent predictor of functional outcome and recurrent stroke [ 11 , 12 ].…”

Potential Value of Poststroke Extracranial Arterial Blood Flow Volume in the Prediction of Stroke Functional Outcome

“…Once brain tissue is damaged, it puts a limit to the full functional recovery of the patient and the effectiveness of subsequent rehabilitation care. Cerebral vasoreactivity and collateral circulation can protect the brain from ischaemic attack [7], and the efficiency of these protective mechanisms can be reflected by the amount of extracranial arterial blood flow volume [8, 9]. Therefore, the higher TEA blood flow volume, the more likely the protective mechanism against cerebral ischemia is effective and hence prevents severe damage to the brain and ultimately favors a better recovery.…”

“…Our previous studies have shown that extracranial arterial blood flow volume can reflect the efficiency of cerebral vasoreactivity and the adequacy of intracranial collateral circulation [8, 9]. The positive and negative percentage changes in the extracranial arterial blood flow volume before and after acetazolamide administration are predictive of positive and negative cerebral vasoreactivity as demonstrated by stable xenon- enhanced CT. An elevated flow of either ≥370 ml/min in the common carotid artery or ≥120 ml/min in the vertebral artery in patients with occlusive carotid disease is indicative of the presence of intracranial collaterals.…”

Color Doppler sonographic evaluation of flow volume of the internal carotid and vertebral arteries after carotid endarterectomy

“…Some studies have shown that an active collateral flow can be detected by CDUS of the cervicocranial arteries by detecting a significantly higher BFV in them. 18 A magnetic resonance angiography study showed that CEA reduces the caliber of the compensatory collateral channels to normal levels. 19 We used CDUS to examine the postprocedural effects of CEA on ipsilateral ICA velocity measurements and BFV measurements of both ICAs and both VAs and correlated the findings to the initial degree of stenosis of the operated ICA.…”