Noninvasive transcranial Doppler ultrasound in intracranial angiomas

Transcranial Doppler ultrasound is a noninvasive method to evaluate flow velocities in the basal cerebral arteries. It can provide hemodynamic data like velocity distributions, intracranial steal phenomena, and functional stenoses in angiomas as illustrated in four patients. This information may supplement conventional neuroradiologic procedures for therapeutic decisions and follow-up.     

Benefit of echocontrast-enhanced transcranial arterial color-coded duplex ultrasound

OBJECTIVES: Proper assessment of the intracranial arteries by transcranial color-coded duplex sonography (TCCD) is occasionally made difficult by an insufficient temporal bone window, an unfavorable insonation angle, or low flow velocity or volume. In these cases, echocontrast could be helpful to increase the diagnostic confidence or to make the diagnosis at all. MATERIAL AND METHODS: We investigated 67 temporal windows of 47 patients with insufficient native transtemporal insonation conditions before and after the application of the second-generation (gas-filled) microbubble contrast agent Sonovue (in 20 patients out of these 47, both temporal windows were insufficient, in the remaining 27 only one side). RESULTS: As compared to the precontrast scans, echocontrast allowed for more segments to be evaluated by pulsed Doppler sonography (p < 0.0001) and for longer lumen segments to be displayed on color mode (p < 0.0001). With the help of contrast medium, flow velocity in the middle cerebral artery could be measured through 65 windows as compared to only 26 windows before contrast was applied (p < 0.0001). CONCLUSIONS: In patients with poor precontrast visualization of intracranial arteries, echocontrast-enhanced TCCD is very helpful.     

Carotid and transcranial color-coded duplex sonography in different types of carotid-cavernous fistula

BACKGROUND AND PURPOSE: Patients with carotid-cavernous fistula (CCF) may undergo direct or indirect shunting. Ultrasonography has value that is complementary to angiography in the assessment and follow-up of these patients. The aim of this study was to characterize findings provided by carotid duplex sonography (CDS) and transcranial color-coded duplex sonography (TCCD) in patients with different types of CCF. METHODS: CDS and TCCD were independently performed by technologists and neurologists. Digital subtraction or MR angiography was interpreted by a neuroradiologist. Ultrasonographic studies were categorized into 4 types: I, direct shunting only; II, direct shunting with a carotid aneurysm; III, indirect shunting only; and IV, mixed (direct and indirect) shunting. In addition to carotid and intracranial flow velocities, volume, and pulsatility, other direct and indirect ultrasound signs of shunting were evaluated. The direct sign of CCF was a mosaic flash detected by TCCD. Alteration of hemodynamic parameters on CDS and demonstration of draining veins with the use of TCCD were considered indirect signs. RESULTS: Fifteen patients (8 men, 7 women) were included in the study. According to angiographic results, patients in ultrasonographic classification types I (n=7) and II (n=3) corresponded to type A of Barrow's classification. Patients with type III (n=8) were Barrow's type C. Type IV (n=1) had a combination of Barrow's types A and C. On ultrasound, both direct and indirect signs were seen in types I, II, and IV CCF. The presence of a 2-colored oval mass divided by a zone of separation without turbulence differentiated type I from type II CCF. All patients with type III CCF had indirect signs, and only 1 patient had direct signs on TCCD. Abnormal TCCD findings were most commonly seen through the transorbital window (100%), followed by the transtemporal window (63%) and transforaminal window (40%). CONCLUSIONS: If only indirect ultrasonographic signs of CCF are present, TCCD can be used to predict an indirect CCF type on the basis of the origin of the fistula. With direct communication between carotid artery and cavernous sinus, both direct and indirect ultrasonographic signs can be found. The combination of CDS/TCCD may provide a noninvasive and reliable way to classify patients with CCF.     

Carotid Doppler and transcranial Doppler in diagnosing transient ischemic attack： A healthy control

INTRODUCTION Basically etiological factor and pathology of transient ischemic attacks (TIA) are atherosclerosis[1-4]. On clinic, TIA is classified into branches of internal carotid artery and mallet-basilar artery on the basis of in- volved vessels. TIA i…     

经颅多普勒和颈动脉超声检测高血压患者无症状性颅内外动脉粥样硬化病变

目的分析无脑缺血症状的高血压患者颅内外动脉粥样硬化病变的发生频率及分布特征,并探讨其危险因素。方法对106例无脑缺血症状的高血压患者采用经颅多普勒超声(Transcranial Doppler,TCD)和颈动脉超声判断颅内外动脉粥样硬化病变,分析各危险因素的影响。结果 69例有颅内外动脉粥样硬化病变,其中23例颅内动脉狭窄,2例颅外颈动脉狭窄或闭塞。颅内动脉狭窄发生率明显高于颅外颈动脉狭窄或闭塞(P<0.05)。Logistic多元回归分析显示与年龄、高血压病病程及高脂血症相关。结论无脑缺血症状的高血压病患者,半数以上存在颅内外动脉粥样硬化病变,年龄、高血压病病程和高脂血症是颅内外动脉粥样硬化病变的独立危险因素。     

Intra- and extracranial circulatory changes in cigarette smokers assessed by ultrasound: transcranial Doppler (TCD) and duplex scanning investigation

The group of 98 "healthy smokers" was analyzed in order to evaluate potential influence of cigarette smoking on intracranial blood flow disturbances and extracranial carotid intimal changes, performing transcranial Doppler (TCD) and Duplex scanning of the carotid arteries. Almost 70% of smokers analyzed in our study had some intracranial circulatory changes, predominantly in the vertebral arteries (35%). Half of smokers analyzed had some pathological intimal changes in the carotid arteries. The most frequent finding was wall thickening (23%) and then calcified (13%) and soft plaques (10%). Dose response relationship between smoking and atherosclerosis is also introduced. More than 30 cigarettes smoked per day can significantly influence plaque development and already 20 cigarettes smoked per day can cause significant intracranial blood flow disturbances. The majority of our investigated smokers were in high risk category for development of cerebrovascular disease and 5% were in a very high risk category. Cessation of cigarette smoking will eliminate it as a risk factor. A low dose-response relation and the development of tolerance produced by exposure to nicotine were also introduced.     

颈动脉支架成形术中经颅多普勒超声检测微栓子信号

目的:观察颈动脉支架成形术中经颅多普勒超声(TCD)检测到的微栓子信号(MES)数量与手术各操作步骤的相关性。方法:对15例严重颈动脉狭窄患者在颈动脉支架成形术中采用TCD进行全程动态MES监测。将整个操作过程分为导丝和脑保护滤网通过狭窄部位、球囊预扩张、支架置入、球囊后扩张、回收脑保护滤网5个阶段,观察手术侧大脑中动脉的MES数量与手术各操作步骤的相关性。结果:15例患者术中各操作阶段均可产生MES。MES数量67~309(中位数173),其中支架置入是微栓子最易脱落的阶段,占MES总数量的54.2%。减少操作步骤可明显减少MES的数量。结论:TCD可以全程动态监测颈动脉支架成形术各个阶段的MES数量,指导手术安全进行。     

踝臂指数、颈部血管彩超、经颅多普勒超声与缺血性脑卒中的相关性研究

目的探讨踝臂指数(ABI)、颈部血管彩超、经颅多普勒超声(TCD)与缺血性卒中的关系。方法对187例患者经过CT/MR检查后分为缺血性卒中及非卒中组,均行颈部血管彩超、ABI、TCD检查,收集相关资料,并进行统计学处理。结果卒中组中ABI及颈部血管彩超异常率显著高于非卒中组(P<0.05);缺血性卒中组颈部血管彩超的ROC曲线下面积大于ABI及TCD(0.60、0.56、0.55,P<0.05)。颈部血管彩超联合ABI的ROC曲线下面积远大于颈部血管彩超联合TCD或TCD联合ABI或三者联合(0.62、0.61、0.56、0.61);结论 ABI、颈动脉彩超、TCD能较好的预测缺血性卒中发生,颈部血管彩超联合ABI能够更有效预测缺血性卒中的发生。     

Demonstration of giant MCA aneurysm by transcranial duplex sonography and color Doppler imaging

Transcranial color Doppler sonography is a new diagnostic technique which allows real-time, colorcoded imaging of basal cerebral arteries, with simultaneous demonstration of parenchymal structures in the B-mode scan. With this technique we were able nonivasively to show a giant fusiform aneurysm of the middle cerebral artery (MCA) in an 11-year-old boy. Transcranial color Doppler sonography through the intact temporal bone demonstrated the size and location of the aneurysm and provided real-time imaging of the pulsating intra-aneurysmal flow. Additionally, duplex sonographic measurements of intravascular flow velocities within the aneurysm and the feeding and draining artery were possible. Postoperatively, patency of the MCA with reduced flow velocities after excision of the aneurysm could be shown. This is the first transcranial color Doppler report in a patient with an intracerebral aneurysm. In our opinion, transcranial color Doppler sonography offers new diagnostic possibilities in patients with cerebrovascular disorders.     

TCD动态监测静脉窦血栓形成五例

目的评价静脉窦血栓形成患者经颅多普勒超声(TCD)检测静脉侧枝的开放和再通情况以及颅内压变化。方法用TCD 2MHz探头检测5例静脉窦血栓形成患者的颅内静脉的血流速度以及动脉频谱形态的变化。结果 5例静脉窦血栓形成患者的颅内静脉(大脑中深静脉、基底静脉)的血流速度均明显增高(139cm/s,118 cm/s,99 cm/s,103 cm/s,58cm/s),动脉频谱呈高阻力,经过治疗,随着病情的好转,颅内静脉血流速度下降,颅内动脉频谱由高阻力型恢复正常。结论 TCD能可靠无创、准确地检测颅内静脉,在病程中通过多次的TCD检查,可以评价静脉窦血栓形成静脉侧枝的开放和再通情况以及颅内压变化。     

经颅多普勒超声和颈动脉超声检测无脑缺血症状的2型糖尿病患者颅内外动脉粥样硬化病变

目的 分析无脑缺血症状的2型糖尿病患者颅内动脉粥样硬化性狭窄和颅外颈动脉粥样硬化病变的发生频率及分布特征,并探讨其危险因素.方法 对94例无脑缺血症状的2型糖尿病住院患者用经颅多普勒超声(TCD)和颈动脉超声判断颅内外动脉粥样硬化病变,颅内动脉只分析狭窄,颅外动脉病变包括颈动脉斑块及狭窄.分析各危险因素的影响.结果 55例(58.5%)有颅内外动脉粥样硬化病变.22例(23.4%)发现有颅内动脉狭窄,明显高于颅外颈动脉狭窄或闭塞(3/94,3.2%,χ~2=16.66,P＜0.01).大脑中动脉是颅内最常受累的动脉(狭窄率17.0%),占狭窄动脉数的58.5%.48例(51.0%)有颅外颈动脉粥样斑块或狭窄.Logistic多元回归分析显示糖尿病病程和合并高血压是颅内外动脉粥样硬化病变的独立危险因素.结论 无脑缺血症状的2型糖尿病住院患者,半数以上有颅内外动脉粥样硬化改变,且与糖尿病病程及合并高血压有关,提示对上述高危患者应常规进行超声检测.     

脑动静脉畸形的多普勒超声研究

本文报道经颅多普勒超声(TCD)研究29例脑动静脉畸形(AVM)的血流动力学改变,50％小型AVM供血动脉的流速正常,50％小型AVM和大中型AVM供血动脉的流速均增快;中型AVM同侧颅外颈内动脉(PICA)流速增快,大型AVM双侧PICA流速均增快。AVM切除后供血动脉流速均减慢、脉动指数(PI)增大,其中中型AVM同侧PICA流速减慢,大型AVM双侧PI-CA流速均减慢且双侧颅内非AVM供血动脉的舒张末期流速减慢和PI增大。3例大型AVM手术中或手术后发生脑血流过度灌注现象。     

Generalized models for quantifying laterality using functional transcranial Doppler ultrasound

We consider how analysis of brain lateralization using functional transcranial Doppler ultrasound (fTCD) data can be brought in line with modern statistical methods typically used in functional magnetic resonance imaging (fMRI). Conventionally, a laterality index is computed in fTCD from the difference between the averages of each hemisphere's signal within a period of interest (POI) over a series of trials. We demonstrate use of generalized linear models (GLMs) and generalized additive models (GAM) to analyze data from individual participants in three published studies (N = 154, 73 and 31), and compare this with results from the conventional POI averaging approach, and with laterality assessed using fMRI (N = 31). The GLM approach was based on classic fMRI analysis that includes a hemodynamic response function as a predictor; the GAM approach estimated the response function from the data, including a term for time relative to epoch start (simple GAM), plus a categorical index corresponding to individual epochs (complex GAM). Individual estimates of the fTCD laterality index are similar across all methods, but error of measurement is lowest using complex GAM. Reliable identification of cases of bilateral language appears to be more accurate with complex GAM. We also show that the GAM-based approach can be used to efficiently analyze more complex designs that incorporate interactions between tasks.     

Benefit of echocontrast-enhanced transcranial color-coded duplex ultrasound in the assessment of intracranial collateral pathways

BACKGROUND AND PURPOSE: Although clinically important, proper assessment of intracranial arterial collateral pathways by transcranial color-coded duplex sonography (TCCD) in patients with internal carotid artery (ICA) high-grade stenosis or occlusion is occasionally made difficult by an insufficient temporal bone window, an unfavorable insonation angle, or low flow velocity or volume. In these cases, echocontrast could be helpful to increase the diagnostic confidence or to make the diagnosis at all. METHODS: We investigated 50 temporal windows of 44 patients with ipsilateral high-grade (>/=70%) ICA stenosis or occlusion and insufficient native transtemporal insonation conditions before and after the application of the echo enhancer Levovist with an infusion pump. RESULTS: Compared with the precontrast scans, echocontrast allowed for more segments to be evaluated by pulsed Doppler sonography (P<0. 0001) and for longer lumen segments to be displayed on color mode (P<0.0001). Also, collateral flow via the anterior and posterior communicating artery could be demonstrated in 25 and 32 scans, respectively, compared with only 1 demonstration of each collateral pathway before the application of contrast medium (both P<0.0001). Similarly, with the help of contrast medium, flow velocity in the middle cerebral artery could be measured in 45 cases compared with only 26 cases before contrast was applied (P<0.0001). CONCLUSIONS:In patients with poor precontrast visualization of intracranial arteries, echocontrast-enhanced TCCD is very helpful in the assessment of intracranial collateral pathways recruited downstream to ICA stenoses and occlusions.     

Transcranial Doppler ultrasound findings in middle cerebral artery occlusion

We evaluated the efficacy of transcranial Doppler ultrasonography in 23 patients suffering from acute middle cerebral artery occlusion. The diagnosis of occlusion was most suggestive when all basal arteries except the affected middle cerebral artery were detectable. Enhanced blood flow velocity in the anterior cerebral artery due to leptomeningeal collateralization was used as a corroborating criterion. With frequent follow-up examinations, we monitored reperfusion of the M1 segment resulting from recanalization or embolus migration in 16 patients. Those patients undergoing recanalization within days after onset of the first symptoms revealed variable clinical courses and lesion patterns on computed tomography, indicating the crucial importance of early and efficient leptomeningeal collateral blood supply. Transcranial Doppler ultrasonography was able to exclude middle cerebral artery occlusion with accuracy, which provides important clinical information. However, distal branch occlusions could not be detected with sufficient exactness.     

高血压不同中医证型与经颅和颈动脉多普勒超声的相关性分析

目的探讨高血压中医辨证分型与经颅和颈动脉多普勒超声检测值之间的关系。方法选择我院2010-07—2014-02收治的高血压患者134例,应用多普勒超声仪检测不同中医证型患者的大脑前动脉(ACA)、大脑中动脉(MCA)、大脑后动脉(PCA)的平均血流速度(Vm)、脉动指数(PI)和颈动脉狭窄程度。结果经Spearman相关性分析显示,高血压中医分型中肝火亢盛、阴虚阳亢、阴阳两虚和痰湿壅盛型与MCA、ACA、PCA的Vm呈负相关性(r=-0.54、-0.34、-0.30,P0.05),与MCA、ACA、PCA的PI呈正相关(r=0.32、0.29、0.22,P0.05)。本组134例高血压患者中颈动脉超声检测显示72例发生不同程度的颈动脉狭窄。轻、中、重度颈动脉狭窄患者间各中医证型比较差异有统计学意义(P0.05),均以痰湿壅盛型狭窄最为严重。结论不同中医证型高血压反映不同程度的颈动脉血管结构改变,超声检测中Vm、PI有可能作为高血压不同中医辨证分型的重要依据。