MRA、TCD及椎动脉超声对椎基底动脉系统缺血性卒中的诊断价值

目的 探讨椎动脉磁共振血管成像(MRA)、经颅多普勒(TCD)及椎动脉超声对椎基底动脉系统缺血性卒中的临床诊断价值.方法 对41例椎基底动脉系统缺血性卒中的患者进行椎动脉MRA、TCD及椎动脉超声检测,观察其异常情况.结果 41例患者中椎动脉MRA异常27例(65.85%),TCD异常32例(78.05%),椎动脉超声异常25例(60.98%).椎动脉MRA能清楚地显示血管病理形态,主要表现为椎动脉局部狭窄、单侧椎动脉变细及血流信号降低.结论 椎动脉MRA、TCD与椎动脉超声的联合检查有助于椎基底动脉系统缺血性卒中的病因诊断.     

MRA、椎动脉彩超对椎基底动脉供血不足的诊断价值

目的 探讨磁共振血管造影(MRA)、椎动脉彩超对椎基底动脉供血不足(VBI)的诊断意义。方法 对临床确诊的60例VBI患者行颈部血管彩超检查,其中32例行MRA检查。结果 MRA异常率71.9％(23/32),分别显示椎基底动脉不同程度狭窄、迂曲。椎动脉彩超异常率为68.3％(41/60),分别显示椎动脉狭窄、迂曲、动脉粥样硬化、斑块形成及流速异常。结论 MRA完整显示椎基底动脉血管结构异常,椎动脉彩超对显示椎动脉内径、斑块形成有特征性,两者检查无创伤性,对VBI的诊断、治疗及判断预后有重要指导意义。     

MRA、椎动脉彩超对椎基底动脉供血不足的诊断价值

目的 探讨磁共振血管造影(MRA)、椎动脉彩超对椎基底动脉供血不足(VBI)的诊断意义。方法 对临床确诊的6d例VBI患者行颈部血管彩超检查，其中32例行MRA检查。结果 MRA异常率71．9％(23／32)，分别显示椎基底动脉不同程度狭窄、迂曲。椎动脉彩超异常率为68．3％(41／60)，分别显示椎动脉狭窄、迂曲、动脉粥样硬化、斑块形成及流速异常。结论 MRA完整显示椎基底动脉血管结构异常，椎动脉彩超对显示椎动脉内径、斑块形成有特征性，两者检查无创伤性，对VBI的诊断、治疗及判断预后有重要指导意义。     

经颅多普勒、MRI和磁共振血管成像对椎-基底动脉供血不足的诊断价值

目的探讨经颅多普勒(TCD)、MRI和磁共振血管成像(MRA)对椎-基底动脉供血不足(VBI)的诊断价值。方法对60例临床诊断为VBI的患者分别进行TCD、MRI和MRA检查．并对检查结果进行分析。结果TCD检查异常53例(88．3％)，其中椎动脉血流速度减慢15例，脑血管硬化6例，脑血管痉挛23例，血管狭窄9例?MRI显示脑干缺血性改变(灌注不足)12例(20．0％)，脑干腔隙性梗死3例(5．0％)：MRA发现椎动脉异常32例(53．3％)。结论TCD检查对VBI诊断的敏感性高，MRA的特异性高：TCD、MRI和MRA联合检查对VBI的病因、病变部位、病理改变有诊断价值。     

TCD、BAEP对椎—基底动脉供血不足的诊断价值

本文对110例椎基底动脉供血不足患者进行了TCD、BAEP的双重检测研究，结果显示在缺血发作期，两者的异常率分别是97．1％和90％（P＞0．05）;缓解期两者的异常率分别为88．2％和63．1％。本研究证实TCD、BAEP能准确、快捷的对椎基底动脉供血不足诊断，阳性率高，有极高的诊断价值。     

椎基底动脉供血不足患者颈部MRA检查分析

目的 初步探讨MRA对椎动脉供血不足的诊断价值。方法 对72例临床诊断为椎基动脉供血不足的患者和25例健康才行颈部MRA检查，并进行分析。结果 病例组异常率为73.6％，对照组28％，两组比较P=0.000，有显著差异。结论 椎基底动脉供血不足患者73.6％存在椎基底病变，MRA能直观显示双侧椎动脉的形态，是VBI患者的一个重要辅助检查方法。     

BAEP与MRA在椎基底动系统TIA中的应用研究

目的:探讨脑干听觉诱发电位(BAEP)及磁共振血管成像(MRA)检查对椎基底动脉系统TIA的早期诊断价值。方法:对60例椎基底动脉系统TIA患者进行BAEP和MRA检查。BAEP异常患者治疗1周后复查,分析其前后变化。同时选取36例健康人行BAEP检查作对照。结果:治疗前患者组BAEP异常44例(73.3%),MRA异常35例(58.3%);治疗后患者组BAEP异常14例(23.3%)。对照组两项检查均正常。结论:BAEP、MRA对椎基底动脉系统TIA早期诊断具有重要价值,二者联合检测有助于缺血定位。     

椎基底动脉供血不足患者颈部MRA检查分析

目的　初步探讨MRA对椎动脉供血不足的诊断价值。方法　对 72例临床诊断为椎基动脉供血不足的患者和 2 5例健康者行颈部MRA检查 ,并进行分析。结果　病例组异常率为 73 6%,对照组 2 8%,两组比较P =0 0 0 0 ,有显著差异。结论　椎基底动脉供血不足患者 73 6%存在椎基底病变 ,MRA能直观地显示双侧椎动脉的形态 ,是VBI患者的一个重要辅助检查方法     

TCD和BAEP对椎基底动脉供血不足的研究

目的　探讨经颅多普勒超声 (TCD)和脑干听觉诱发电位 (BAEP)对椎基底动脉供血不足 (VBI)患者的诊断价值。方法　对 1 60例VBI患者行TCD和BAEP检测 ,观察椎基底动脉流速以及脑干电生理指标 ,并对流速与潜伏期作相关回归分析。结果　疾病组椎基底动脉(VBA)流速明显低于对照组 (P <0 0 0 1 )。V波潜伏期、峰间潜伏期及Ⅲ V/I Ⅲ比值较对照组延长。TCD和ABEP异常率分别为 80 %和81 3% ,以VBA流速降低和脑干型异常为主要特点。基底动脉流速降低与潜伏期延长存在负直线相关关系 ,流速越低则潜伏期越长。结论　TCD和BAEP可能是诊断和研究VBI一个重要的方法。     

TCD、BAEP、MRI对椎基底动脉供血不足的诊断价值

目的 探讨椎基底动脉供血不足(VBI)可靠的辅助诊断方法．方法 对临床确诊的VBI 115例患者同时进行了经颅多普勒(TCD),脑干听觉诱发电位(BAEP),脑颅核磁共振(MRI)检查.结果:TCD异常率为82.2%,BAEP异常率为72.1%,MRI异常率为26.1%,结论:TCD,BAEP异常率高可为VBI早期诊断提供客观依据,TCD应作为首选的监测手段,也证明了VBI患者在形态学无明显改变时MRI除与VBI的鉴别诊断外,不应作为VBI的常规检查.     

磁共振血管成像、经颅多普勒及颈动脉超声对颈动脉系统短暂性脑缺血发作的诊断价值

目的 探讨磁共振血管成像（MRA）、经颅多普勒（TCD）和颈动脉超声对颈动脉系统短暂性脑缺血发作（TIA）的诊断价值。方法 对42例颈动脉系统TIA患者进行MRA、TCD和颈动脉超声检测，观察其异常情况。结果 颈动脉MRA异常12例（28．6％），脑MRA异常32例（76．2％），其中8例二者均异常，大多为颈动脉轻～重度狭窄；TCD异常30例（71．4％）（此30例脑MRA均异常）；颈动脉超声异常16例（38．1％）（其中颈动脉MRA异常12例）。结论 MRA、TCD和颈动脉超声3种方法联合应用，可对颈动脉系统TIA的病因及诊断作出客观的评价。     

BAEP转颈试验对VBI诊断价值的研究

目的：研究脑干听觉诱发电位（ＢＡＥＰ）转颈试验对椎基底动脉供血不足（ＶＢＩ）的诊断价值。方法：对临床诊断为ＶＢＩ而普通ＢＡＥＰ、ＴＣＤ检查阴性的３２例病人,作ＢＡＥＰ转颈试验。结果：ＢＡＥＰ,阳性率为３７．５％。结论：ＢＡＥＰ转颈试验可提高ＶＢＩ病人的阳性检出率。     

Pitfall of Electron Beam Computed Tomography Angiography in Diagnosis of Subclavian Steal Syndrome

A patient presented with vertebrobasilar insufficiency during exertion. Vertebral duplex and transcranial Doppler ultrasonography showed reversal of flow in both intracranial and extracranial vertebral and basilar arteries, suggesting bilateral subclavian and vertebrobasilar steal. Electron beam computed tomography angiography (CTA) showed no evidence of subclavian artery stenosis including normal vertebral artery origin on both sides. However, digital subtraction angiography revealed complete occlusion of both subclavian arteries with retrograde flow from both vertebral and basilar arteries to reconstitute both subclavian arteries. This false-negative finding on CTA in detection of subclavian steal syndrome (SSS) is due to inappropriate contrast administration technique and postprocessing method, inability to differentiate flow direction, and lack of hemodynamic time sequences. This study demonstrates a pitfall of CTA in diagnosis of SSS compared to more reliable hemodynamic information obtained by duplex and transcranial Doppler ultrasonography, and digital subtraction angiography.     

经颅多普勒与核磁共振血管造影对比检测颅内大动脉的临床价值探讨

目的比较经颅多普勒(transcranialDoppler,TCD)与核磁共振血管造影(magneticreso-nanceangiography,MRA)检测颅内大动脉的特点,探讨其临床应用价值。方法应用TCD和MRA检测16例患者共32根大脑中动脉,比较其检测结果。结果TCD检查显示,大脑中动脉闭塞3根,狭窄16根,流速增快9根,正常4根;MRA显示,大脑中动脉闭塞4根,狭窄13根,正常15根。TCD与MRA检查的符合率于大脑中动脉闭塞时为75.0%(3/4),狭窄时为81.3%(13/16),正常时86.7%(13/15)。结论TCD与MRA对颅内大动脉的检测具有较高的一致性,TCD较MRA方便、迅速、经济,MRA较TCD直观、全面,二者联合检测可比较准确地提供颅内血管情况。     

多普勒超声和增强磁共振血管造影对颈动脉、椎动脉和基底动脉在后循环缺血性病因中的诊断价值

目的：探讨经颅多普勒超声（TCD）、颈动脉和椎动脉彩色多普勒超声（CDU）、颅颈部增强磁共振血管造影（CE-MRA）检测对后循环缺血（PCI）病因诊断的价值。方法：对临床已确诊为PCI的60例患者行TCD和颈动脉、椎动脉CDU检测,其中47例另行颅颈部CE-MRA检查。结果：①在TCD检测的60例患者中显示后循环血流异常45例（75％）。②颈动脉和椎动脉CDU检测,发现椎动脉异常38例（63．33％）,其中椎动脉狭窄变细20例、椎动脉走行迂曲8例、仅有椎动脉壁硬化而无狭窄6例及椎动脉硬化伴有斑块形成10例。⑧47例患者颅颈部CE-MRA检查：后循环异常33例,阳性率为70．21％。其中椎动脉异常27／47例（57．45％）、椎动脉起始狭窄15／47例（31．91％）、椎动脉起始变异3／47例（6．38％）、椎动脉迂曲6／47例（12．77％）、椎动脉V2段局部狭窄2例、椎动脉V4段轻度狭窄2例。结论：TCD可以对椎动脉血流动力学的变化进行量化分析,可作为PCI的早期筛查手段。颈动脉和椎动脉CDU检测在显示颅外段椎动脉内径,椎动脉壁动脉硬化、斑块形成和钙化等动脉壁结构的变化上占优势,而整体形态学影像则不如CE—MRA。颅颈部CE-MRA可显示椎动脉狭窄,在椎动脉整体形态的显像上占优势,可为PCI的病因诊断提供依据。     

Phase-Contrast Magnetic Resonance Angiography for the Determination of Cerebrovascular Reserve

Cerebrovascular reserve (CVR) is the potential for cerebral arteriolar dilatation to occur, in response to decreased cerebral perfusion pressure, in order to maintain constant cerebral blood flow. Diminution or absence of CVR is considered a risk factor for stroke. Current methods for determining CVR include singlephoton emission computed tomography, positron emission tomography and transcranial Doppler (TCD) ultrasonography. However, significant advantages could derive from the utilization of magnetic resonance angiography (MRA) based on the concurrent acquisition of hemodynamic information (CVR and collateral flow) with phase?contrast (PC) techniques and vascular morphology with three?dimensional, time?of?flight methods. With a 1.5?T scanner and acetazolamide (AZM), an arteriolar dilator, CVR was determined in 7 normal subjects. Mean flow velocity in the middle cerebral arteries was determined by PC MRA before and after AZM administration. For comparative purposes, mean flow velocities in the same middle cerebral arteries were determined by TCD before and after AZM administration. The mean flow velocities were as follows (mean ± standard deviation, n = 7): 40 ± 8 (PC MRA) versus 61 ±10 cm/sec (TCD) before AZM treatment and 58 ±11 (PC MRA) versus 85 ±15 cm/sec (TCD) after AZM administration. The increase in mean flow velocity (before vs after AZM), that is, the CVR, was 45 ±11 % as shown by PC MRA and 39 ± 14% as shown by TCD. Although significant differences were present between the mean flow velocities measured before and those after AZM administration, as determined by PC MRA and TCD, the CVR was not significantly different (45 vs 39%, respectively). These preliminary results suggest that PC MRA may be a method for determining CVR.     

SPECT脑灌注显像在椎基底动脉供血不足的临床研究

目的 探讨单光子发射计算机断层扫描(SPECT)脑灌注显像在椎基底动脉供血不足(vertebrobasilar insuf-ficiency,VBI)的临床应用价值,并与其他对VBI的研究方法相比较,力图找出一个研究VBI较客观理想的临床方法。方法 将临床确诊VBI的患者50例,全部进行了经颅多普勒超声(TCD)、颈部血管彩色超声多普勒(CDFI)、SPECT检查,将其中普通SPECT显示正常的19例患者,48 h后予以口服乙酰唑胺2 g,2 h后再行SPECT检查。50例患者中26例进行了核磁共振血管成像(MRA)检查,其中1例还进行了正电子发射计算机断层扫描(PET)检查。结果50例患者TCD阳性率为66％,CDFI阳性率为56％,普通SPECT阳性率为62％。三种方法阳性率无明显差异,加用乙酰唑胺后的SPECT检查阳性率提高到86％,与TCD和CDFI比较有显著性差异。SPECT显示缺血部分多在枕颞叶等椎基底动脉(VBA)系统供血区域。26例患者MRA显示有2例椎动脉狭窄。其中1例患者MRA、SPECT显示正常,口服乙酰唑胺后SPECT检查及PET检查显示有颞枕叶缺血。结论 TCD和CDFI在VBI的诊断上可作为粗略的筛选手段,MRA在VBI的诊断价值可能不大,加用乙酰唑胺后SPECT阳性率明显提高,我们认为其对VBI的诊断具有重要价值,值得临床推广。     

Advantages of color Doppler imaging for the evaluation of vertebral arteries.

Assessment of the vertebral arteries is often difficult with conventional duplex ultrasonography. This study of 60 patients aimed to determine the potential advantages of color Doppler imaging over conventional duplex ultrasonography in the evaluation of vertebral arteries, specifically three extracranial segments of these vessels. Both methods allowed visualization of the vertebral artery in the midcervical course (V2 and distal V1 segments) in all subjects. Color Doppler imaging appeared more effective for visualization of the V0 and the proximal V1 segments (on the right side in 88% of patients and on the left side in 73%). Conventional duplex ultrasonography imaged the ostium on the right side in 80% of patients and on the left side in 65%, but was difficult and time-consuming. Visualization at the atlas loop (V3 segment) was rarely successful with duplex sonography, whereas color Doppler imaging visualized the vertebral artery on the right side in 87% of patients and on the left side in 85%. Color Doppler imaging allows better visualization of the proximal and distal segments of the vertebral arteries, compared to conventional duplex ultrasonography.     

Usefulness of carotid duplex ultrasonography in a patient with moyamoya disease]

The patient is a 35-year-old man who had a medical history of epilepsy in childhood. He came to our hospital because of transient disturbance of consciousness and left hemiplegia just after evacuation. At first, we thought that he had epilepsy with Todd's palsy. But we had to do a differential diagnosis for a transient ischemic attack such as paradoxical embolism, because his symptoms occurred just after evacuation. An electroencephalogram and brain computerized tomography were immediately performed, but no abnormality was detected. Hematologic studies were normal, and no deep vein thrombosis was detected in the veins of the lower extremities by duplex ultrasonography Doppler. But carotid duplex ultrasonography showed an increase in end-diastolic flow velocity and a decrease in vascular resistance in both external carotid arteries. These findings indicated that there was arteriovenous malformation such as moyamoya disease. Brain magnetic resonance imaging showed spotty high signal lesions in the subcortical areas on a fluid-attenuated inversion-recovery(FLAIR) image, and the middle cerebral artery was not visualized on magnetic resonance angiography (MRA). Cerebral angiography demonstrated moyamoya vessels in the brain and collateral circulation from the external carotid artery. Therefore, we diagnosed him as having moyamoya disease. Duplex ultrasonography of the common and, internal carotid, and vertebral arteries is a widely-used technique. Recently, cerebral angiography, MRA and transcranial Doppler have been applied to detect intracranial vascular malformation. But these results suggested that moyamoya disease could be detected by means of carotid duplex ultrasonography. Finally, we considered that carotid duplex ultrasonography was not only a noninvasive screening method but also a useful for the diagnosis of moyamoya disease.