超声对颈内动脉严重狭窄或闭塞时颅内侧支循环情况的评价

目的应用经颅彩色双功超声(TCCS)评价颈内动脉严重狭窄或闭塞时颅内侧支循环的建立情况。方法采用彩色多普勒血流成像筛选单侧颈内动脉严重狭窄或闭塞的患者,用TCCS检测颅内主要动脉的血流动力学变化。结果①有前交通动脉参与的侧支循环与中风发生呈负相关,而眼动脉(OA)参与的侧支循环与中风发生呈正相关。②无症状组及有症状组颈内动脉严重狭窄或闭塞的患者患侧大脑中动脉(MCA)的收缩期峰值流速、搏动指数明显低于健侧及对照组。无症状组患侧OA的收缩期峰值流速、搏动指数与健侧及对照组比较无统计学意义,而有症状组OA的收缩期峰值流速、搏动指数明显低于健侧及对照组。结论TCCS检测颅内主要动脉的血流动力学变化,可以方便地评价颅内侧支循环状态,对颈内动脉严重狭窄或闭塞患者治疗和预后的判断具有重要的临床价值。     

经颅多普勒超声检测颈内动脉重度狭窄或闭塞患者血流动力学的改变

目的 分析颈内动脉(ICA)重度狭窄或闭塞后颈总动脉(CCA)与大脑中动脉(MCA)血流动力学的改变,以及侧支循环开放情况,以提高经颅多普勒超声(TCD)对ICA 重度狭窄或闭塞检测的准确性.方法 选择经全脑数字减影血管造影(DSA)检查证实一侧ICA 重度狭窄或闭塞且双侧CCA 和MCA 正常或狭窄＜50 %的患者30 例.全部行TCD 检查,测量双侧CCA 和MCA 的收缩期血流速度(Vs),平均血流速度(Vm)和搏动指数(PI).并与DSA 对比,分析TCD 判断侧支循环的敏感性及特异性.结果 (1)ICA 狭窄或闭塞侧CCA 的Vm 和Vs 均较无病变侧明显降低(P ＜0.05 ).病变侧PI 较无病变侧明显增高(P ＜0.05 ).(2)ICA 狭窄或闭塞侧MCA 的Vm 、Vs 和PI 均较无病变侧明显降低(P ＜0.05 ).(3 )TCD 检测前交通动脉(ACoA)开放占66.7 %(20 /30 ),后交通动脉(PCoA)开放占60.0%(18 /30 ),颈内-外动脉侧支循环开放占43.3 %(13 / 30).与DSA 结果相比较TCD 显示侧支循环的敏感性为90%,特异性为85%.结论 TCD 检查CCA 和MCA 的血流动力学变化及侧支循环开放情况对ICA 重度狭窄或闭塞的准确诊断具有重要指导价值.     

大脑中动脉狭窄对颅外段颈内动脉血流动力学的影响

目的研究不同程度的大脑中动脉(MCA)狭窄对颅外段颈内动脉(ICA)血流动力学的影响。方法本研究纳入单侧MCA狭窄或闭塞的患者98例,根据狭窄程度分为对照组(MCA中度狭窄,N=46)与观察组(MCA重度狭窄或闭塞,N=52),使用彩色多普勒超声测量两侧颅外段ICA的收缩期峰值流速(Vp)、舒张末期流速(Vd)、平均流速(Vm)、搏动指数(PI)。结果与对照组相比,观察组患侧ICA的Vp、Vm及Vd较健侧明显降低(41.17cm/s vs48.76cm/s,21.22cm/s vs 28.23cm/s,11.82cm/s vs 17.92cm/s,P均<0.05),而患侧PI值明显高于健侧(1.43vs1.20,P<0.01),PI值差值显著增大(0.28vs 0.06,P<0.05)。结论颅外段颈内动脉血流动力学的改变在一定程度上提示了大脑中动脉狭窄的严重程度,能够有效提高TCD对于大脑中动脉狭窄或闭塞进行诊断的准确性。     

一侧颈内动脉严重狭窄或闭塞时同侧颈总动脉血流频谱分析

目的:探讨一侧颈内动脉严重狭窄或闭塞时,同侧颈总动脉血流频谱的改变。材料与方法:采用彩色多普勒超声诊断仪对150例一侧颈内动脉重度、极重度或闭塞的患者进行同侧颈总动脉血流频谱分析,测量颈总动脉收缩期流速,舒张末期流速,平均血流速度及搏动指数,阻力指数等指标,其中重度、极重度及闭塞的患者各50例。结果:一侧颈内动脉严重狭窄或闭塞的患者同侧颈总动脉的血流速度明显较无病变侧的降低,搏动指数及阻力指数均较无病变侧显著增高。结论:颈总动脉血流频谱的异常改变可以间接估测颈内动脉狭窄程度,对颈内动脉狭窄程度的判定有一定的价值。     

下肢动脉闭塞性疾病的彩色多普勒流速曲线分析

下肢动脉闭塞性病变是指各种因素所致的髂动脉以下的下肢动脉狭窄乃至闭塞的一组疾病。近年来,彩色多普勒血流成像在该类疾病的检查中得到了广泛应用,它可同时提供形态学和血流动力学信息。通过对获得的多普勒流速曲线观察、分析,可方便、准确地诊断一些有临床意义的动脉狭窄性疾病。 1 动脉狭窄时的血流动力学改变和观察指标 静息状态下,正常下肢动脉为高搏动性波形,表现为三相波:第一相为心脏收缩期迅速流向肢体远端的血流波形;第二相为主动脉瓣关闭及外周血管弹性回缩时血液返流的波形;第三相为舒张期大动脉弹性回缩血液再次流向肢体远端的血流波形。正常下肢动脉流速曲线表现为曲线较窄,曲线下窗口存在,流速曲线亮暗适中,包绕线较光滑。在静态下血管内径减少超过50％以上时,远端会有明显的血流动力学改变和压力下降。明显的动脉狭窄(动脉内径减少50％以上)有四个区域的血流动力学改变。狭窄处血流加快,且与狭窄程度成正比;狭窄稍远端可见高速射流和涡流,并延伸至数厘米远谢流消失后,血流又再层流化,     

锁骨下动脉狭窄与闭塞对颅内椎动脉的影响

目的探讨经颅多普勒(Transcranial Doppler，TCD)在锁骨下动脉狭窄与闭塞时频谱的形态特点及诊断方法。方法选取临床诊断为锁骨下动脉窃血的患者148例，其中男8l例，女67例，年龄范围在41～76岁，平均年龄63岁。记录并分析研究1钙例患者椎动脉、基底动脉及桡动脉的频谱形态特点，及其中部分患者的DSA与MRA等影像学检查结果。结果148例患者TCD检测频谱呈特征性改变者116例，其中椎动脉频谱方向逆转者86例，仅收缩早期出现切迹而频谱方向正常者19例。86例椎动脉频谱方向逆转者中，39例随机进行了DSA或MRA认检查，其结果与TCD检测结果完全一致，表现为锁骨下动脉或无名动脉狭窄或闭塞。TCD检测桡动脉均表现为低阻力、低搏动性血流频谱；19例收缩早期出现切迹而频谱方向正常者中，11例出现低搏动性或搏动性较对侧减低的血流频谱；5例DSA提示锁骨下动脉轻度狭窄；6例MRA提示锁骨下动脉狭窄或显影淡；11例二维彩超提示锁骨下动脉近端狭窄。结论TCD检测血管的频谱形态特征可以反映锁骨下动脉窃血综合征的血流动力学特点，研究椎动脉的TCD改交有助于临床对锁骨下动脉缺血及锁骨下动脉窃血综合征的诊断。     

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。     

颈内动脉严重狭窄或闭塞的超声诊断及临床价值

目的 利用彩色多普勒血流成像（CDFI）观察颅内动脉严重狭窄或闭塞的血流动力学变化特点，并探讨其临床价值。方法 对17例经二维及彩色多普勒超声检测的颅内动脉狭窄或闭塞病例进行回顾分析。结果 颈内动脉严重狭窄或闭塞全部发生在起始部，闭塞者患侧颈总动脉血流速度减慢，同侧颈外动脉血流速度增快；严重狭窄者局部血流速度明显增快，其远端及近端血流速度减慢。其中5例严重狭窄者行手术或介入治疗，术后血流动力学明显改善。结论 超声二维图像可清晰的显示颈内动脉闭塞或狭窄程度，彩色多普勒超声可准确判定病变动脉血流动力学变化情况，二者结合，可对颈内动脉病变作出准确诊断，对其所引起供血不足作出预报，并对临床疗效进行观察评价。     

原发性高血压的脑动脉血流动力学检测及其价值

目的：探讨原发性高血压患脑动脉血流动力学状态并分析其与高血压病程之间的关系。方法：利用TCD技术检测了100例原发性高血压患的脑动脉，将100例原发性高血压患按病程长短分三个组，分析其脑动脉血流动态变化。结果：病程3个月至3年的患主要表现为血流速度参数增高（P均＜0．001）；病程3年以上至6年的患血流收缩期流速峰值（VP）增高（P均＜0．001），而舒张末期最低流速（VD）降低（P均＜0．01），搏动指数（PI）、阻力指数（RI）增高（P均＜0．05）；病程6年以上的患血流速度各参数均降低（P均＜0．001），搏动指数（PI）、阻力指数（RI）逐渐增高（P均＜0．001）。结论：利用TCD技术检测脑动脉血流动力学变化，可用于评价高血压患的脑动脉功能状况。     

超声评价颈动脉狭窄的颅内侧支循环建立情况

目的　了解颈内动脉狭窄时 :①颈内 外动脉间吻合支循环建立情况 ;②侧支循环建立时 ,颈总动脉的血流动力学特点。方法　用彩色多普勒血流成像 ,选择一侧颈内动脉完全或 99%以上阻塞的、病程≥ 0 .5年的 5 6例病人 ,根据对侧颈内动脉狭窄程度分为四组。检查颈内动脉完全阻塞侧的眼动脉血流方向 ,确定侧支循环建立情况 ,然后测双侧颈总动脉的血流动力学指标。结果　①对侧颈内动脉狭窄程度在 95 %以上时 ,颈内 外动脉吻合支开放率 85 .7% (12 / 14 ) ;②侧支循环开放时 ,双侧颈总动脉的收缩期峰速 (PSV)和舒张期末速度 (EDV)均增高。结论　①双侧颈内动脉严重狭窄时 ,颈内 外动脉间的吻合支开放 ,保证脑组织的血供 ;②CDFI检查眼动脉和颈总动脉的血流动力学情况 ,可以方便地评价颅内侧支循环状态     

椎动脉颅内段血流速度及频谱波形异常的分析与诊断

目的探讨椎动脉颅内段血流异常的类型、病变部位及产生原因。方法对299例经磁共振血管成像和/或数字减影血管造影证实的颅内外动脉严重狭窄或闭塞患者,采用经颅多普勒超声(TCD)和颈动脉连续波多普勒超声(CWD)评估椎动脉颅内段血流异常。结果299例患者共检测598支椎动脉颅内段,其中508支血流异常:狭窄血流(32支)、无血流(17支)、低流速低阻力(58支)、低流速高阻力(42支)、代偿血流(287支)和窃血频谱(72支)。狭窄血流或无血流均在病变部位直接检出,其他4种类型血流异常则是病变部位近端或远端动脉的间接血流改变。结论采用TCD和CWD评估椎动脉颅内段血流异常可为临床寻找后循环缺血的原因和更深入研究缺血性脑血管病的发病机制提供重要的客观依据。     

颈内动脉严重狭窄或闭塞后颈总动脉与颈内动脉虹吸段血流频谱的改变

目的：分析颈内动脉严重狭窄或闭塞（ＩＣＡＳＯ）后颈总动脉（ＣＣＡ）和颈内动脉虹吸段（ＳＩＰＨＡ）血流频谱的改变,提高经颅多普勒超声（ＴＣＤ）对ＩＣＡＳＯ的检出率和准确性。方法：ＩＣＡＳＯ患者１２０例,全部经颈部血管彩超检查证实,其中６２例经脑血管造影（ＤＳＡ）进一步确诊双侧病变３３例,单侧病变８７例,共有病变血管１５３条（狭窄９４条,闭塞５９条）。全部行ＴＣＤ检查。结果：（１）狭窄或闭塞侧颈总动脉     

彩色多普勒超声评价颈内-外动脉侧支循环对颈总动脉血流动力学的影响

目的探讨颈内动脉（ICA）重度狭窄或闭塞时颈内-外动脉侧支循环（IEACC）是否开放对患侧颈总动脉（CCA）血流动力学的影响。方法选择临床及影像资料完整，单侧ICA颅外段狭窄70％～99％（74例）、闭塞（86例），且健侧ICA及双侧CCA正常或狭窄程度〈50％的患者。按IEACC是否开放将患者分为ICA狭窄70％-99％IEACC开放组（42例）和IEACC未开放组（32例），闭塞IEACC开放组（43例）和IEACC未开放组（43例）。采用彩色多普勒超声测量CCA和颈外动脉（ECA）的收缩期峰值流速（PSV）、舒张末期流速（EDV）、平均流速（MV）、阻力指数（RI），计算CCA的血流量（BFV）。分别比较ICA狭窄70％-99％及闭塞时，IEACC是否开放对患侧CCA血流动力学的影响，分析ECA在IEACC开放后患侧、健侧血流动力学的变化特点。结果（1）ICA狭窄70％-99％组与闭塞组IEACC开放者患侧CCA的EDV、BFV高于IEACC未开放者，EDV分别为（15±5）cm／s、（12±5）cm／s（P=0．010）与（14±6）cm／s、（10±6）cm／s（P=0．002），BFV分别为（676±271）ml／min、（557±188）ml／min（P=0．036）与（606±218）ml／min、（488±180）ml／min（P=0．035），而PSV、MV、RI差异均无统计学意义；（2）ICA狭窄70％～99％组与闭塞组IEACC开放者比较，患侧CCA的PSV、EDV、MV、RI、BFV差异均无统计学意义；IEACC未开放患者比较，70％～99％组的EDV及BFV高于闭塞组，分别为（12±5）cm／s、（10±6）cm／s（P=0．014）与（557±188）ml／min、（488±180）ml／min（P=0．047）；（3）ICA狭窄70％～99％组及闭塞组IEACC开放者患侧ECA的PSV、EDV、MV高于健侧，分别为（124±35）cm／s、（107±22）cm／s（P〈0．001），（34±12）cm／s、（22±8）cm／s（P〈0．001）与（64±18）cm／s、（50±11）cm／s（P〈0．001）；RI值患侧低于健侧，分别为0．72±0．07、0．79±0．07（P〈0．001）；IEACC未开放?     

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.     

糖尿病患者冠状动脉左前降支远段血流动力学变化的超声研究

目的应用冠脉血流显像技术观察分析糖尿病患者静息状态下左前降支(LAD)远段血流动力学改变,了解该变化与心肌微血管损害之间的关系。方法对31例非胰岛素依赖性糖尿病患者进行冠脉多普勒血流显像检查,观察LAD远段在静息状态下的冠脉血流信号,记录流速曲线,测定收缩期峰值速度(SPV),收缩期速度时间积分(VTIs),舒张期峰值速度(DPV),舒张期速度时间积分(VTId),舒张期加速时间(TPVd),舒张期减速度(DDR)以及舒张期减速时间(DDD),并与正常对照组进行比较。结果31例患者中有2例未测及前降支远段血流,其余29例均能较清晰显示,SPV、DPV与正常对照组比较无显著性意义VTIs、VTId、TPVd和DDD明显低于正常对照组(P<0.01),DDR高于正常对照组(P<0.05)。结论糖尿病患者心肌内微血管的损害可以影响心外膜冠脉的血流动力学,而经胸冠脉多普勒血流显像能直接观测前降支远段冠脉血流,早期发现糖尿病患者潜在的心肌缺血。     

Radiologic Importance of a High‐Resistive Vertebral Artery Doppler Waveform on Carotid Duplex Ultrasonography

Objective. The appearance of the vertebral artery (VA) waveform on a pulsed Doppler examination performed during standard carotid duplex ultrasonography (CDU) may suggest vertebrobasilar disease. We sought to determine the radiographic importance of high‐resistive (HR) pulsed Doppler VA waveforms seen on CDU. Methods. The Noninvasive Vascular Laboratory database was queried for CDU studies noting the HR VA Doppler signal. Studies with unilateral or bilateral HR and antegrade VA waveforms with correlative neuroimaging studies within 60 days were included. Imaging reports were reviewed to determine the following: (1) a normal VA; (2) at least moderate distal VA or basilar artery (BA) stenosis, occlusion, or dissection; (3) a congenitally diminutive VA; or (4) other abnormalities. Results. Of 1338 studies with 1 or more HR VA waveforms, 79 studies met all inclusion criteria (n = 157 arteries) and had adequate correlative neuroimaging. There were 90 HR VAs, and HR waveforms were equally distributed between right and left sides. The mean peak systolic velocity of HR versus low‐resistive (LR) VAs was 51.7 versus 63.6 cm/s (P = .04); the mean end‐diastolic velocity of HR versus LR VAs was 4.6 versus 17.3 cm/s (P < .001); and the resistive index of HR versus LR VAs was 0.92 versus 0.73 (P < .001). Of all HR VAs, 18.9% were normal; 38.9% had distal vertebrobasilar stenosis or occlusion; 35.6% were congenitally diminutive; and 6.7% had other abnormalities (proximal stenosis, excessive tortuosity, fibromuscular dysplasia, and BA hypoplasia). Conclusions. The finding of an HR spectral Doppler signal in the VA was associated with major vertebrobasilar disease (46% of cases) and should prompt additional neuroimaging in the appropriate clinical situation.     

Redefined duplex ultrasonographic criteria for diagnosis of carotid artery stenosis

OBJECTIVE: To evaluate duplex ultrasonographic criteria for the determination of 50% or more and 70% or more stenosis of the diameter of the internal carotid artery based on conventional angiography in order to align ultrasonographic diagnostic categories with current clinical management schemes. PATIENTS AND METHODS: Between January 1, 1995, and June 30, 1999, 915 patients underwent both carotid duplex ultrasonography and cerebral angiography within 30 days at Mayo Clinic, Rochester, Minn. Of these patients, 294 were excluded from this study because of occlusion of one or both of the internal carotid arteries or atypical flow characteristics. In the remaining 621 patients (61 % male, 39% female; mean age, 67.7 years [range, 14-88 years]), 1218 vessels were available for correlation. Several Doppler ultrasonographic velocity variables were compared with the angiographic findings by use of receiver operating characteristic curve analysis. The primary end point was verification of optimal ultrasonographic criteria to diagnose 70% or more internal carotid artery stenosis. The secondary end point was establishment of threshold values to detect stenosis of 50% or more. RESULTS: At angiography, 382 patients had internal carotid arteries with 70% or more stenosis. Peak systolic and end diastolic velocities of the internal carotid artery and internal carotid artery:common carotid artery peak systolic velocity ratios were measured. For an internal carotid artery stenosis of 70% or more, a peak systolic velocity of 230 cm/s or more resulted in a sensitivity of 86.4%, a specificity of 90.1%, a positive predictive value of 82.7%, a negative predictive value of 92.3%, and an accuracy of 88.8%. An end diastolic velocity of 70 cm/s or more and an internal carotid artery:common carotid artery ratio of 3.2 or more yielded similar values. For an internal carotid artery stenosis of 50% or more, a peak systolic velocity of 130 cm/s or more resulted in a sensitivity of 92.1 %, a specificity of 89.5%, a positive predictive value of 90.3%, a negative predictive value of 91.3%, and an overall accuracy of 90.8%. An internal carotid artery:common carotid artery ratio of 1.6 or more yielded similar values. CONCLUSION: In our ultrasonography laboratory, a carotid artery stenosis of 70% or more (for which carotid endarterectomy is typically recommended in symptomatic patients) is diagnosed reliably with the following duplex ultrasonographic criteria: a peak systolic velocity of 230 cm/s or more, an end diastolic velocity of 70 cm/s or more, or an internal carotid artery:common carotid artery ratio of 3.2 or more.     

Intermittent drop in blood flow velocity in the internal carotid artery and its branches

Extracranial Doppler sonography and transcranial Doppler sonography (TCD) allow the assessment and monitoring of hemodynamic and embolic events in cerebrovascular diseases. We describe an unusual hemodynamic phenomenon in a patient with intracranial carotid siphon stenosis and no clinical symptoms of stenosis. TCD examination suggested and angiography confirmed stenosis of the left internal carotid artery siphon. TCD examination revealed a sudden, intermittent drop in blood flow velocity in both the prestenotic and poststenotic segments of the internal carotid artery, whereas cardiac hemodynamic parameters were unaffected. Embolic signals were detected in the poststenotic vessels only. We speculate that such sonographic findings may be caused by intermittent vessel occlusions due to the reversible displacement of an intraluminal thrombus in relation to the cardiac cycle.     

Functional assessment of high-grade ICA stenosis with duplex ultrasound and transcranial Doppler

Background: Duplex ultrasound (DUS) has shown a >90% accuracy compared to angiography, concerning the degree of internal carotid artery (ICA) stenosis. However, uncertainty may occur in a severe stenosis, in which peak systolic velocity (PSV) may decrease owing to high flow resistance or high backward pressure. We investigated intracranial collateral flows using transcranial Doppler (TCD) to further evaluate the hemodynamic significance of high‐grade ICA stenosis. Methods: In this retrospective study, 320 consecutive symptomatic patients were examined. The degree of ICA stenosis and collateral capacity in the circle of Willis was investigated by DUS and TCD. In addition, magnetic resonance angiography (MRA) was added in a subgroup of 204 patients. The criterion for hemodynamic significant ICA stenosis was established collateral flow. Results: In 91% of all symptomatic vessels (291 vessels), an ICA stenosis of ≥70% was found. Established collateral flow always indicated precerebral carotid artery disease of ≥70%. Furthermore, in 11% of the whole study material, collateral reserve capacity was found despite high‐grade (≥70%) ICA stenosis. PSV in ICA <2·5 m s^?1 was combined with established collateral flow and MRA stenosis of ≥70% in 9% (19 arterial systems). In 4%, doubt existed concerning the degree of stenosis after DUS. Conclusion: Transcranial Doppler helps to determine whether an ICA stenosis is of hemodynamic significance and to assess collateral patterns. Established collateral blood flow will help to identify patients with ≥70% (ECST) carotid artery disease. TCD might be of value when flow velocity criteria combined with plaque assessment by DUS are inclusive. Other diagnostic methods may also be considered.