颈动脉连续波多普勒超声评估颅内侧支循环

目的探讨颈动脉连续波多普勒超声评估颅内侧支循环。方法对80例无脑供血动脉狭窄性病变患者,在行颈总动脉压迫试验时采用4 MHz连续波探头检测对侧颈内动脉起始段和同侧椎动脉寰枢段血流速度变化。并对连续波多普勒超声与经颅多普勒超声检测的侧支循环方式结果进行比较。结果颈动脉连续波多普勒超声检出前交通动脉侧支开放76例(95%),经颅多普勒超声检出前交通动脉侧支开放76例(95%)。在受检的160个后交通动脉侧支中,颈动脉连续波多普勒超声检出后交通动脉侧支开放140个(88%),经颅多普勒超声检出132个(83%)。结论颅外动脉连续波多普勒超声结合颈总动脉压迫试验检测颅内侧支循环既安全又方便,其准确率与经颅多普勒超声一致。     

经颅多普勒超声评估分水岭梗死患者的Willis环侧支循环能力

目的探讨分水岭梗死患者的Willis环侧支循环能力。方法对100例一侧颈内动脉闭塞患者,采用经颅多普勒超声检测Willis环的侧支循环通路。结果48例分水岭梗死患者,27%未发现Willis环侧支循环通路,13%出现后交通动脉侧支血流。52例无分水岭梗死患者,4%未发现Willis环侧支循环通路,后交通动脉侧支开放的比率增高至52%(P<0.01)。前交通动脉侧支开放的比率两组大致相同,分别为60%和63%。结论一侧颈内动脉闭塞患者,无Willis环侧支循环和低比率的后交通动脉侧支开放与发生分水岭梗死相关。     

颈动脉连续波多普勒超声评估颅内侧支循环

目的探讨颈动脉连续波多普勒超声评估颅内侧支循环。方法对80例无脑供血动脉狭窄性病变患者，在行颈总动脉压迫试验时采用4MHz连续波探头检测对侧颈内动脉起始段和同侧椎动脉寰枢段血流速度变化。并对连续波多普勒超声与经颅多普勒超声检测的侧支循环方式结果进行比较。结果颈动脉连续波多普勒超声检出前交通动脉侧支开放76例（95％），经颅多普勒超声检出前交通动脉侧支开放76例（95％）。在受检的160个后交通动脉侧支中，颈动脉连续波多普勒超声检出后交通动脉侧支开放140个（88％），经颅多普勒超声检出132个（83％）。结论颅外动脉连续波多普勒超声结合颈总动脉压迫试验检测颅内侧支循环既安全又方便，其准确率与经颅多普勒超声一致。     

经颅多普勒超声评估分水岭梗死患者的Willis环侧支循环能力

目的探讨分水岭梗死患者的Willis环侧支循环能力。方法对100例一侧颈内动脉闭塞患者，采用经颅多普勒超声检测Willis环的侧支循环通路。结果48例分水岭梗死患者，27％未发现Willis环侧支循环通路，13％出现后交通动脉侧支血流。52例无分水岭梗死患者，4％未发现Willis环侧支循环通路，后交通动脉侧支开放的比率增高至52％（P〈0．01）。前交通动脉侧支开放的比率两组大致相同，分别为60％和63％。结论一侧颈内动脉闭塞患者，无Willis环侧支循环和低比率的后交通动脉侧支开放与发生分水岭梗死相关。     

经颅彩色多普勒血流显像对脑血管显示率及Willis环侧支血流的研究

目的 研究正常成人颅内动脉的显示率，评价Willis环前、后交通动脉循环功能。 方法 256例正常成人按年龄男女均各分3组，采用经颅多普勒血流显像（TCCDFI）、能量多普勒（CDE）及超声造影（ECE）技术，观察颅内动脉走行及血流方向。并通过压迫颈总动脉（CCA），观察大脑前动脉（ACA）、后动脉（PCA）血流方向及血流速度的变化，判断Willis环前、后交通动脉循环功能。 结果 （1）颅内动脉成功显示率男女均随年龄增长而下降。3组女性间有明显差异，老年女性明显低于老年男性（P〈0．05）。Willis环完全未显示的老年组被检者行ECE仍有85％可清晰显示；（2）前交通动脉功能开放率男女分别为87．6％、83．3％，后交通动脉左侧分别为28．9％、34．1％，右侧分别为34．4％、29．2％。 结论 TCCDFI、CDE及ECE能实时观察颅内动脉走行及血流方向，评价前、后交通动脉循环功能，可作为颅内动脉检查的有效方法。     

急性颈内动脉闭塞颅内循环的变化及临床意义

目的 分析急性颈内动脉闭塞后颅内血流动力学的变化及临床意义.方法 对68例经影像学检查证实急性单侧颈内动脉颅外段闭塞患者,采用经颅多普勒超声(TCD)检测颅内主要动脉的血流动力学变化.结果 患侧大脑中动脉峰值流速和搏动指数均显著低于健侧(P<0.001).在侧支循环开放中,前交通动脉开放占48.53%(33/68),后交通动脉开放为42.65%(29/68),眼动脉参与的侧支循环占32.35%(22/68),无交通支开放14.71%(10/68).患者颅内侧支循环开放,侧支途径两支以上者、患侧大脑中动脉峰值流速>60 cm/s者,临床预后相对较好.结论 TCD检测颅内主要动脉的血流状况,可以快速方便地评价颅内侧支循环状态,对急性颈内动脉闭塞患者治疗方法选择和预后判断具有重要的临床价值.     

颈动脉海绵窦瘘的经颅多普勒超声研究

采用彩色三维经颅多普勒观察18例颈动脉海绵窦瘘血流情况，发现其引流静脉多以眼上静脉为主；患侧颈内动脉流速明显高于健侧；患侧MCA、ACA流速低于健侧。压迫患侧颈总动脉，患侧颈内动脉（瘘口以上）出现不同程度的倒灌血流。眼上静脉的动脉化且血流反向的频谱特点及患侧颈内动脉倒灌血流为颈内动脉海绵窦瘘的特征性表现。经眶窗检测颈内动脉虹吸段时，其流速受瘘口所在位置的影响，观察颅内盗血情况可粗略估价瘘口大小。经颅多普勒检测颈动脉海绵窦瘘还可了解患者Willis环代偿能力，为必要时行一侧颈内动脉闭塞提供参考依据。     

多普勒超声检测颈动脉内膜剥脱术后脑血流动力学的改变

目的　探讨多普勒超声在颈动脉内膜剥脱术对改善脑血液供应效果评估中的应用价值。方法　应用彩色多普勒血流显像和经颅多普勒超声分别测定 11例症状性颈内动脉狭窄患者手术前后术侧颈内动脉血流速度、血流量和双侧大脑中动脉血流速度 ,并观察Willis环和眼动脉的血流方向。结果　术后同侧颈内动脉血流速度显著减慢 [术前 (2 91.70± 65 .2 5 )cm /s ,术后 (10 0 .85± 3 5 .68)cm /s ,P <0 .0 0 1] ,血流量显著增加 [术前(2 0 8.19± 49.94)ml/min ,术后 (3 83 .68± 3 7.2 6)ml/min ,P <0 .0 0 1] ;大脑中动脉血流速度较术前略有增高 ,但差异无显著性意义 ;术后侧支循环的反向血流转化为正向血流。结论　彩色多普勒血流显像和经颅多普勒通过对颈内动脉、大脑中动脉血流参数的测定及颅内侧支循环的观察 ,可有效评价手术对改善同侧脑血液供应的治疗效果     

经颅彩色多普勒超声诊断脑动脉急性栓塞1例

患者男,62岁.左侧肢体活动乏力2 h,颈总动脉及颈内动脉颅外段彩超未见异常,经颅彩色多普勒(TCCD)显示:右侧大脑中动脉(RMCA)水平段血流速度减低,最大流速 54 cm/s,右侧后交通动脉开放,考虑 RMCA 水平段以远急性栓塞,余各检测动脉血流通畅,血流速度、方向正常,频谱收缩峰稍圆钝,峰时延迟(小于0.12 s).     

颈内动脉颅外段重度狭窄或闭塞后颅内循环的经颅多普勒超声分析

目的:应用经颅多普勒超声(TCD)对颈内动脉颅外段重度狭窄或闭塞的颅内血流动力学进行分析。方法:采用64层螺旋CT血管造影(CTA)筛查单侧重度颈动脉狭窄或闭塞的患者,用TCD对颅内动脉的血流动力学改变进行评价。结果:(1)重度颈内动脉狭窄或闭塞病变同侧的大脑中动脉平均血流速度和搏动指数均低于对侧。(2)侧支循环开放形成,前交通动脉开放占63.5%,后交通动脉开放占46%,颈内外动脉开放占44%。结论:重度颈内动脉颅外段狭窄或闭塞使同侧半球血流速度下降,侧支循环建立,TCD与CTA从不同角度对颈动脉病变提供诊断治疗依据。     

自制简易Matas试验架的临床应用

目的：介绍一种自制的Matas试验架,探讨其临床应用效果。方法：介绍Matas试验架的制作和使用方法。并对10例颈动脉体瘤、4例巨大海绵窦动脉瘤、5例外伤性颈内动脉海绵窦瘘患者进行颈动脉压迫耐受训练。通过数字减影血管造影（DSA）和经颅多普勒（TCD）检查,了解大脑动脉及Willis环侧支循环的建立和代偿情况。结果：DSA和TCD显示大脑动脉及Willis环侧支循环的建立和代偿情况良好。19例患者均实施手术治疗和介入治疗,无一例发生并发症。结论：使用自制Matas试验架来进行颈动脉压迫训练,以其定位准确、压迫可靠、稳定性好、效果确切等优点,为成功手术提供了精确的术前评估和耐受训练。     

Evaluation of posterior cerebral artery blood flow with transcranial Doppler sonography: value and risk of common carotid artery compression

PURPOSE: Investigations of the posterior cerebral arteries (PCA) by transcranial Doppler sonography (TCD) may be less reliable than investigations of the anterior part of the circle of Willis. Nevertheless, a true PCA may be identified by manual compression of the proximal common carotid artery (CCA) during TCD. Therefore, we used CCA compression in clinically indicated TCD studies and assessed retrospectively its risks and prospectively its benefits for PCA evaluations. METHODS: Using the transtemporal approach, we prospectively assessed flow velocities in posteriorly located blood vessels in 180 consecutive patients before and during CCA compression. The complications of CCA compression were retrospectively reviewed in all 3,383 clinical TCD investigations performed over an 8-year period. RESULTS: Decreased flow velocities during ipsilateral CCA compression occurred in 17% of patients. A PCA-like vessel with perfusion from the carotid artery or PCA supply from the carotid circulation was unmasked. Mixed distal PCA support by the posterior communicating artery and proximal PCA could not be shown by TCD. Transient cerebral symptoms occurred in less than 0.4% of the 3,383 retrospectively reviewed TCD investigations; no other adverse effects were seen. CONCLUSIONS: TCD without CCA compression may lead to false identification of the PCA. Since transient cerebral symptoms during CCA compression are rare, CCA compression can be used when a clinical TCD investigation of intracranial collateral blood flow compensation is indicated or when the identification of a cerebral artery is uncertain.     

Transcranial measurement of blood velocities in the basal cerebral arteries using pulsed Doppler ultrasound: a method of assessing the Circle of Willis

Transcranial pulsed Doppler ultrasound and spectral analysis were used for detection of blood velocities in the basal cerebral arteries. The Doppler transducer was placed superior to the zygomatic arch and during insonation of the middle cerebral artery care was taken to obtain maximum Doppler-shift frequency signals since this allowed a small angle between the ultrasound beam and this artery. Doppler signals were obtained from the middle, anterior, and posterior cerebral arteries in 20 volunteers with the average depth of the Doppler gate at 4.9 (4.6-5.2 cm), 5.2 (4.9-5.4 cm), and 6.3 cm (6.0-6.9 cm), respectively. These measurements were in agreement with those obtained for 15 cadaver studies, in whom the distance from the proposed site of the Doppler transducer to each basal cerebral artery was measured as 4.7 +/- 0.6, 5.3 +/- 0.5, and 5.9 +/- 0.9 cm, respectively. The reproducibility of middle cerebral artery blood velocity values was tested in seven subjects and showed a variation of not more than 8% in any individual. The method was used in combination with common carotid compression to assess four patients who had occlusive extracranial carotid disease; in three the disease was more severe on one side and reversal of blood flow in the proximal ipsilateral anterior cerebral artery was demonstrated, consistent with cross flow from the contralateral side via the anterior communicating artery of the Circle of Willis. In the fourth patient augmentation of posterior cerebral artery blood velocities during common carotid compression indicated the major collateral source was from the vertebrobasilar system.     

经颅多普勒超声评估颈内动脉严重狭窄或闭塞患者的侧支循环代偿能力

目的探讨经颅多普勒超声（TCD）评估颈内动脉严重狭窄或闭塞患者的侧支循环代偿能力。方法对60例一侧颈内动脉严重狭窄或闭塞患者,根据临床上有无脑缺血和神经功能障碍体征,将患者分为症状性严重狭窄或闭塞组（44例）和无症状性严重狭窄或闭塞组（16例）。TCD柃测Willis环和眼动脉的侧支循环通路。结果TCD显示54例前交通动脉侧支开放,31例后交通动脉侧支开放,15例眼动脉侧支开放。3例症状性严重狭窄或闭塞患者未发现侧支循环。无症状性严重狭窄或闭塞患者的大脑中动脉平均血流速度高于症状性闭塞患者（P〈0．01）。结论TCD有助于了解颈内动脉系统动脉严重狭窄或闭塞患者的侧支循环代偿能力,为评估治疗效果和预后提供重要的客观依据。     

经颅彩色多普勒血流成像与能量多普勒观察正常成人颅内动脉

目的研究正常成人颅内动脉的结构及血流动力学参数,生理状态下评价Willis环前、后交通动脉循环功能.方法216例正常成人按年龄、性别分组,采用经颅彩色多普勒血流成像(TCCDFI)与能量多普勒(CDE)技术,分别显示颅内动脉、测量其内径及血流动力学参数,通过压迫颈总动脉,判断交通动脉循环功能.结果①颅内动脉成功显示率男、女均随年龄增长而下降,血管内径、流速随之变小(P＜0.05),而搏动指数、阻力指数随之增大(P＜0.05),同一组男女间血管内径有明显差别(P＜0.05),而其他参数无明显差别;②前交通动脉功能开放率男女分别为88.9%、82.9%,后交通动脉左侧29.5%、34.1%,右侧35.2%、29.2%.结论TCCDFI与CDE能实时动态观察颅内动脉的结构及测量血流动力学参数,评价前、后交通动脉循环功能,可作为颅内动脉检查的首选方法.     

Pathophysiology of unilateral high-grade carotid artery stenosis: evaluation of intracranial haemodynamics by analysis of velocity waveforms from the middle cerebral artery.

1. Transcranial flow velocity waves were measured via Doppler sonography of the middle cerebral artery during hypo-, hyper- and normo-capnia. Applying the principle of vascular impedance, flow velocity waves were analysed in 30 young subjects, 37 elderly subjects and 18 patients with high-grade unilateral internal carotid artery disease. 2. There was evidence that the relative peak-to-peak velocity in the middle cerebral artery could serve as an index of peripheral wave reflection and cerebral resistance (CRi). The response of CRi to changes in arterial CO2 concentration (CRi reactivity) showed a clear age-dependency. However, the absolute side-to-side asymmetry of CRi reactivity (delta R) did not vary with age and could be used to define a normal range (0-4%CRi/vol.%CO2). 3. Selective angiography demonstrated no cerebral cross-flow through the anterior part of the circle of Willis in nine patients with carotid artery stenosis whose absolute delta R was above the normal range and whose CRi reactivity of the affected hemisphere was lower than that of the healthy opposite hemisphere. Conversely, another group of nine patients, whose ipsilateral CRi reactivity was higher than the contralateral CRi reactivity, demonstrated cross-flow through the anterior part of the circle of Willis. 4. delta R may be used to identify patients who have high-grade internal carotid artery stenosis and present with low cerebral vascular resistance owing to poor intracerebral collaterals.     

In vivo flow territory mapping of major brain feeding arteries

The ability to visualize the perfusion territories of major feeding arteries to the brain is important for many clinical applications. Since the work of Duret in 1874 on vascularization of the brain, many textbooks and atlases have shown schematic drawings of the supply areas of the major cerebral arteries. Recent postmortem studies demonstrated that the variability of the cerebral vascular territories is significantly greater than previously assumed. The aim of the present study was to investigate in vivo, the variability of flow territories of major brain feeding arteries. Flow territory mapping of the anterior (internal carotid arteries) and posterior (basilar artery) circulation was performed in 115 (58 +/- 9 years of age) subjects with selective arterial spin labeling MRI. Flow territory maps for the entire population indicated significant variation in flow territories. However, when the subjects are further categorized into groups with a complete circle of Willis, with a missing A1 segment and with a unilateral or bilateral fetal-type posterior cerebral artery, the results showed considerably lower variation within groups. It is therefore concluded that, the variation observed from the entire population is mainly caused by anatomical variants of the circle of Willis. To relate focal brain lesions to underlying flow territories in individual cases, knowledge of the anatomy of the circle of Willis is essential.     

Granulocyte-macrophage colony-stimulating factor as an arteriogenic factor in the treatment of ischaemic stroke

Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces arteriogenic growth of collateral vessels after occlusion of cardiac or peripheral arteries. Recently, evidence has been provided that arteriogenesis also occurs in the brain under conditions of reduced arterial blood supply. Hemispheric hypoperfusion induced by unilateral carotid and bilateral vertebral artery occlusion (three-vessel occlusion, [3-VO]) led to the growth of the anterior and posterior segments of the circle of Willis, which is the main collateral pathway between the origins of the anterior, middle and posterior cerebral arteries. GM-CSF applied subcutaneously at daily doses of 40 μg·kg^-1 resulted in the marked acceleration of this process. Within one week after the onset of treatment, the diameter of the posterior segment of the circle of Willis enlarged to 170% of control, blood flow and the haemodynamic reserve capacity of the brain returned to normal, and haemodynamic stroke, induced after 3-VO by systemic hypotension, was greatly alleviated. GM-CSF-induced stimulation of arteriogenesis in the hypoperfused brain thus provides powerful protection against ischaemic stroke.