[Transcranial Doppler measurement of hemodynamics in the major cerebral arteries].
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Using a pulsed Doppler velocity meter, the authors assessed by a transcranial approach, in order to obtain an idea on the normal haemodynamics of the basal cerebral arteries, the maximal systolic blood flow (Vmax., m.s-1) in these arteries in a group of 25 healthy young men and in 20 healthy children. In different arteries of the two groups the following mean values of Vmax. were recorded: middle cerebral artery 0.73 +/- 0.11 parallel 0.80 +/- 0.17 m.s-1; anterior cerebral artery 0.55 +/- 0.06 parallel 0.51 +/- 0.09 m.s-1 and posterior cerebral artery 0.44 +/- 0.04 parallel 0.40 +/- 0.02 m.s-1. The assessed values of Vmax. are in agreement with data of other authors. Using the transcranial Doppler method (TD), the authors recorded in 10 children examined in the acute and subsequent stage of cerebrovascular disease recanalization of original occlusions in the anterior, middle and posterior cerebral arteries in the carotid siphon and in the basal artery and improved cerebral haemodynamics in A-V malformation in the basal ganglia. The TD method thus makes it possible to diagnose and follow up the course of these diseases. To illustrate the assessment of the function of the circle of Willis we made in three of our followed up patients with stenosis of extracranial internal carotid arteries static compression tests of both common carotid arteries. The TD method makes it possible to follow up the course of haemodynamic changes in diseases of the cerebral arteries and along with the angiographic examination it extends and supplements the evaluation of the pathological condition of the cerebral arteries and its extent.Keywords:
Anterior cerebral artery
Circle of Willis
Posterior cerebral artery
Transcranial Doppler
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Most of the transcranial Doppler (TCD) experimental studies on cerebral haemodynamics have been performed in the rabbit because of the similarity between its Willis circle and that of the human, but these studies have mainly been limited to the basilar artery. The present study was aimed at extending the use of TCD sonography to all other large cerebral arteries. In anaesthetised rabbits, these arteries were insonated from three different recording sites, i.e. top‐cranial, suboccipital and orbital, using a two‐channel pulsed Doppler device equipped with 4 and 8 MHz probes. First, discrimination between intra‐ and extracranial arteries was achieved through a standard ‘rebreathing’ test (hypercapnic‐hypoxic stimulation). The distinctive blood velocity response patterns, reflecting the different extents of metabolic reactivity in intra‐ and extracranial territories, are described and discussed. Intracranial arteries were then identified on the basis of their response to ipsi‐ and contralateral common carotid artery occlusion. This procedure allowed recording from the following arteries: anterior common trunk, anterior cerebral, internal carotid, middle cerebral and basilar; the latter could be simultaneously monitored with any of the others. This study provides an experimental model allowing investigation of regional differences in the haemodynamic response to neurogenic and pharmacological stimuli.
Circle of Willis
Anterior cerebral artery
Transcranial Doppler
Posterior cerebral artery
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• The transcranial Doppler sonographic findings of 61 patients with middle cerebral artery (MCA) disease were compared with those of 535 controls. According to computed tomographic, angiographic, and/or autopsy findings, the patients were classified as having MCA occlusive lesions in the central (sphenoidal) part or in peripheral branches or MCA stenosis. With MCA lesions, the MCA flow velocity (FV) was reduced. At the same time the anterior cerebral artery FV increased because of collateral flow over leptomeningeal anastomoses. Central MCA lesions showed less marked changes than did peripheral lesions. In MCA stenosis a steep rise of MCA FV appeared inside the stenotic segment. If there was a high-grade stenosis or occlusion of the internal carotid artery, a collateral circulation over the anterior part of the circle of Willis was seen in addition to the changes caused by the MCA disease. From these hemodynamic changes, transcranial Doppler sonographic diagnostic criteria for MCA occlusive and stenotic lesions were established.
Transcranial Doppler
Circle of Willis
Anterior cerebral artery
Collateral circulation
Anterior communicating artery
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Objective To evaluate the function of color Doppler on the collateral circulation Willis of circle in healthy adults and analyze the difference between man and woman.Methods 286 healthy adults were enrolled in this study.The course and blood flow direction of their cerebral arteries were observed by transcranial color Doppler flow imaging(TCCDFI) and contrast-enhanced ultrasound(CEUS).The function of anterior and posterior communicating arteries(ACoA and PCoA respectively) of Willis circle were respectively assessed by the changes of direction of anterior cerebral artery(ACA) and blood flow velocity of posterior cerebral artery(PCA) during common carotid artery(CCA) compression. Results Among 286 healthy adults,213 cerebral arteries could be clearly visualized by TCCDFI,including 118 men and 95 women.10 men and women each selected of remaining 73 cases could be seen only after CEUS.The rate of the functional patency rate of ACoA for men and women was 86.7%(111 cases) and 83.8%(88 cases),left PCoA was 31.2%(40 cases) and 33.3%(35 cases),right PCoA was 33.6%(43 cases) and 34.3%(36 cases),respectively.There was no significant difference between man and woman(P0.05).Conclusion The course and blood flow direction of their cerebral arteries can be observed real-timely.The functional patency of ACoA and PCoA can be evaluated by TCCDFI and CEUS.The functional patency rate of communicating artery for man and woman exists no significant difference.
Circle of Willis
Anterior cerebral artery
Anterior communicating artery
Collateral circulation
Posterior cerebral artery
Posterior communicating artery
Transcranial Doppler
Color doppler
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Background and Purpose The aim of this investigation was to compare the respective efficacy of transcranial Doppler sonography (TCD) and magnetic resonance angiography (MRA) for the assessment of intracranial hemodynamics in patients with extracranial occlusion or severe stenosis of the internal carotid artery (ICA). Methods Twenty-five patients with unilateral ICA occlusion (n=20) or tight stenosis (n=5) demonstrated by duplex scanning or angiography were studied with both TCD and MRA. Three-dimensional time-of-flight MRA was used for the evaluation of extracranial-intracranial ICAs. Collateralization through the circle of Willis was investigated by means of selective two-dimensional MRA with presaturation of the carotid siphon, ophthalmic artery, or basilar artery. TCD was performed according to published standards: Anterior, middle, and posterior cerebral arteries were insonated through the temporal window, and carotid siphon and ophthalmic artery were assessed through a transorbital approach. Collateralization through the anterior circle of Willis was assumed if anterior cerebral artery flow was reversed, through the external carotid artery if ophthalmic artery flow was reversed, and through the basilar artery if the ratio of ipsilateral to contralateral posterior cerebral artery velocity was greater than 50%. TCD and MRA were performed by different investigators unaware of the results obtained with the other technique. Results In every case time-of-flight MRA demonstrated the ICA occlusion or stenosis. There was an excellent correlation (κ=0.64) between TCD and MRA in assessing the hemodynamic contribution of the anterior part of the circle of Willis, whereas MRA was unable to detect the anastomotic pathway of the ophthalmic artery (κ=0.32). The contribution of the posterior communicating artery was difficult to assess with both techniques, but in three cases only MRA showed unequivocal evidence of collateralization. In three cases of middle cerebral artery stenosis TCD was superior to MRA in demonstrating the patency of the vessel. Conclusions TCD and MRA should be considered complementary techniques. Combining the findings of both examinations may help to better understand the changes in intracranial hemodynamics produced by extracranial carotid occlusion. The contribution of the ophthalmic pathway, although important for the intraorbital structures, is probably of limited functional significance to the hemispheric blood supply.
Circle of Willis
Anterior cerebral artery
Posterior communicating artery
Magnetic resonance angiography
Transcranial Doppler
Posterior cerebral artery
Anterior communicating artery
Collateral circulation
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Citations (98)
Using a pulsed Doppler velocity meter, the authors assessed by a transcranial approach, in order to obtain an idea on the normal haemodynamics of the basal cerebral arteries, the maximal systolic blood flow (Vmax., m.s-1) in these arteries in a group of 25 healthy young men and in 20 healthy children. In different arteries of the two groups the following mean values of Vmax. were recorded: middle cerebral artery 0.73 +/- 0.11 parallel 0.80 +/- 0.17 m.s-1; anterior cerebral artery 0.55 +/- 0.06 parallel 0.51 +/- 0.09 m.s-1 and posterior cerebral artery 0.44 +/- 0.04 parallel 0.40 +/- 0.02 m.s-1. The assessed values of Vmax. are in agreement with data of other authors. Using the transcranial Doppler method (TD), the authors recorded in 10 children examined in the acute and subsequent stage of cerebrovascular disease recanalization of original occlusions in the anterior, middle and posterior cerebral arteries in the carotid siphon and in the basal artery and improved cerebral haemodynamics in A-V malformation in the basal ganglia. The TD method thus makes it possible to diagnose and follow up the course of these diseases. To illustrate the assessment of the function of the circle of Willis we made in three of our followed up patients with stenosis of extracranial internal carotid arteries static compression tests of both common carotid arteries. The TD method makes it possible to follow up the course of haemodynamic changes in diseases of the cerebral arteries and along with the angiographic examination it extends and supplements the evaluation of the pathological condition of the cerebral arteries and its extent.
Anterior cerebral artery
Circle of Willis
Posterior cerebral artery
Transcranial Doppler
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By means of transcranial Doppler (TCD), the author reports intracranial haemodynamic consequences of 57 stenosis or occlusions of the internal carotid artery (ICA), 13 dissections and 44 atheromatous lesions, in 50 patients 32 of whom having had angiography. If a stenosis is significant, the curve of the middle cerebral artery (MCA) becomes dampened and PTI (Pulsatility Transmission Index) diminishes. In this series, the association MCA curve dampened and PTI lower than 0.90 is the evidence of a more than 90% stenosis, except in 2 atheromatous and symptomatic occlusions. No precise explanation for these exceptions is given by literature. An ICA stenosis has also an influence on communicating arteries. In this study, collateralisation by the circle of Willis exists in 14% of 50-75% stenosis, 72.7% of 75-90% stenosis and 100% of more than 90% stenosis. It can depend on anterior communicating artery (ACoA) alone, posterior communicating artery (PCoA) alone or both. Detailed study of the 3 groups leads to the hypothesis of a hierarchy in the function of the communicating arteries, ACoA having the priority.
Circle of Willis
Transcranial Doppler
Anterior communicating artery
Posterior communicating artery
Posterior cerebral artery
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Objective: To promote the clinical value of applying transcranial Doppler test(TCD) to monitor the cerebral hemodynamic changes before tumor-carotid segment block resection, while the patients were having the carotid pressure training, under the guidance of TCD. Methods: Fourteen patients were selected. Before and after carotid artery obstruction. The blood velocity changes of anterior cerebral artery(ACA), middle cerebral artery(MCA) and posterior cerebral artery(PCD) on each side were measured by TCD(through temporal windows). Results: Nine of the 14 cases(64.3%) were found that the compensative capacity of their Willis circle were insufficient through examination of DSA, MATAS and TCD. After receiving the pressure training for 4 to 6 weeks, the cerebral collateral circulations were constructed well via observation of TCD. All blood velocity of the affected side of ACA, MCA and PCA had reached the level before obstruction. After receiving the pressure training for the first time, the velocity of ACA and MCA had significant differences compared with those of receiving training before(P0.004 and P0.03), while there was no significant differences between the velocity before and 6 weeks after training(P0.05). This conform to the criteria of the carotid resection. Conclusions: TCD is a non-traumatic and reproducibility way to monitor cerebral blood velocity, which is safe and reliable and easily accepted by patients, especially important for tumor-carotid segment block resection, but the question whether DSA will be completely replaced by TCD needs further studies.
Transcranial Doppler
Anterior cerebral artery
Posterior cerebral artery
Collateral circulation
Circle of Willis
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PURPOSE To determine the accuracy of transcranial Doppler (TCD) ultrasound for evaluation of collateral supply through the circle of Willis in patients with internal carotid artery (ICA) occlusion. METHODS The evaluation of the collateral pathways through the circle of Willis with TCD ultrasound and with cerebral angiography was compared in 40 patients (30 men, 10 women; mean age, 55 +/- 9 years) in a total of 44 ICA occlusions of which 43 had a suitable ipsilateral temporal bone window for TCD examination. RESULTS By TCD, a patent anterior communicating artery is indicated by a reversal blood flow in the A1-segment of the anterior cerebral artery or by a prompt fall of blood velocity in the middle cerebral artery after compression of the nonoccluded contralateral carotid artery. In 42 of 43 instances of ICA occlusion, TCD and angiography agreed in the evaluation of a present or absent anterior communicating artery collateral supply. TCD9s sensitivity was 95%, its specificity 100%. A collateral supply through the basilar artery was assumed with TCD when there was: (a) a basilar artery blood velocity of more than 70 cm/s; (b) a marked increase of basilar artery blood velocity after compression of the nonoccluded carotid artery; (c) an evident side-to-side asymmetry of the blood velocity of the posterior cerebral arteries with high blood velocity ipsilateral to the ICA occlusion. For evaluating the collateralization via the basilar artery, TCD and angiography agreed in 37 of 40 ICA occlusions. TCD9s sensitivity was 87%, its specificity 95%. CONCLUSIONS TCD is a reliable tool for the evaluation of the collateral supply in patients with ICA occlusions.
Circle of Willis
Anterior cerebral artery
Transcranial Doppler
Posterior communicating artery
Posterior cerebral artery
Anterior communicating artery
Collateral circulation
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Citations (88)
By means of transcranial Doppler (TCD), the author reports intracranial haemodynamic consequences of 57 stenosis or occlusions of the internal carotid artery (ICA), 13 dissections and 44 atheromatous lesions, in 50 patients 32 of whom having had angiography. If a stenosis is significant, the curve of the middle cerebral artery (MCA) becomes dampened and PTI (Pulsatility Transmission Index) diminishes. In this series, the association MCA curve dampened and PTI lower than 0.90 is the evidence of a more than 90% stenosis, except in 2 atheromatous and symptomatic occlusions. No precise explanation for these exceptions is given by literature. An ICA stenosis has also an influence on communicating arteries. In this study, collateralisation by the circle of Willis exists in 14% of 50-75% stenosis, 72.7% of 75-90% stenosis and 100% of more than 90% stenosis. It can depend on anterior communicating artery (ACoA) alone, posterior communicating artery (PCoA) alone or both. Detailed study of the 3 groups leads to the hypothesis of a hierarchy in the function of the communicating arteries, ACoA having the priority.
Circle of Willis
Transcranial Doppler
Anterior communicating artery
Posterior communicating artery
Posterior cerebral artery
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Hemodynamic examination by transcranial Doppler in patients with unilateral carotid artery occlusion
Objective To explore the relationship between the changing of peak blood velocity and pulsatility index in the side of internal carotid artery occlusion with opening of Willis circle and intra-(extracranial) arterial communication.Methods This study group includes 112 patients with extracranial segments of internal carotid arterial occlusion in one side and the other side normal or stenosis less than 50%,and 112 control patients without cerebrovascular disease and both extracranial and intracranial segment of internal carotid arteries were normal by color Doppler flow imaging.The peak systolic velocity(PSV) and pulsatility index(PI) of the bilateral middle cerebral artery(MCA),anterior cerebral artery(ACA) and posterior cerebral artery(PCA) were measured,the difference of PSV and PI of bilateral MCA,ACA,PCA in the occlusion group and control group were compared respectively.The PSV difference(PSVD) and PI difference(PID) of the occluded side were counted.Results The PSVD and PID of bilateral MCA in occlusion group were significantly higher than control group(PSVD(61 cm/s),P=0.000;(PID)70%,P=0.000).There was obviously asymmetry between bilateral MCA,ACA,and PCA in occlusion group.The PSV and PI of MCA and ACA in the occluded side were significantly lower than the normal side(P=0.000).The PSV of PCA in the occuded side was significantly higher and the PI was significantly lower than normal side((P=)0.000 respectively).PSV of MCA in the occluded side correlated with bilateral ACA and PCA(P=0.000,(P=)0.000,(P=)0.006 respectively).(Conclusion) Aggregate analysis of PSV and PI,and PSVD and PID in bilateral MCA by TCD will increase recognition of abnormal hemodynamic in the patients with unilateral internal carotid occlusion.
Circle of Willis
Posterior cerebral artery
Anterior cerebral artery
Transcranial Doppler
Posterior communicating artery
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