磁共振血管成像Willis环的变异及其意义

目的：调查在MRA下Willis环的变异情况，并探讨MRA评价Willis环的临床意义。方法：回顾性分析204例MRI检查脑内无明显异常的3D－TOF MR血管成像图像，统计各个动脉的变异情况。MRA未被显示的动脉被判断为缺如，对称性动脉一侧直径为对侧直径1／2以下者被认为发育不全。结果：A1段的缺如上8．3％，发育不全占10．8％，A1段的发育不良或缺如与同侧PCoA增粗呈正相关；ACoA显示率41．7％，且男性大于女 性；PCoA的显示率41．2％，女性大于男性，胚胎型PCoA发生率29．9％，永存三叉动脉发生率0．5％。结论：MRA评价Willis环变异有重要的临床意义。     

MDCT血管成像对颅内动脉及颅底Willis环解剖变异和其代偿潜能的评估

目的:探讨国人颅内动脉和颅底Willis环的解剖变异及其对颅底动脉环代偿潜能的影响.方法:对76例临床怀疑为各种脑血管疾病患者行64层螺旋CT脑血管成像,在独立工作站上行VR、MIP、MPR及Tree VR多模式脑血管重组.使用不同的旋转轴观察颅内脑供血动脉及脑底动脉环的空间解剖细节.结果:76例患者中,4例因烟雾病前、后循环失去正常解剖形态,未作详细分型,其余72例共发现近代型17例、原始型2例、过渡型2例、混合型12例、发育不全型28例、当代型7例及不定型4例,其中,前循环完整者56例(77.78 %),后循环完整者36例(50%),整环完整者30例(41.67%),Willis环结构典型,具有良好代偿潜能的16例(22.22%).结论:64层螺旋CT脑血管成像能很好地显示Willis环的解剖变异,对Willis环血流代偿潜能进行初步评估,Willis 环解剖变异影响其血流代偿.     

MDCT血管成像研究黔南少数民族地区颅底Willis环解剖变异及分型

目的　探讨贵州省黔南布州依族及苗族成人Willis环解剖变异及分型,为黔南地区少数民族脑血管疾病提供对照。 方法　本研究为回顾性研究,连续纳入黔南州人民医院2011年12月～2017年2月期间CT及MRI检查正常,并作CTA检查黔南布依族或苗族成人513名,将检查数据采用西门子signo工作站,行VR、MIP及MPR多模式、多角度观察Willis环的发育情况进行分型,分析各种类型的情况。 结果　根据组成动脉的发育情况,将513例正常脑动脉Willis环分为4型,Ⅰ型3.7%（19例）;Ⅱ型0.1%(5例);Ⅲ型65.5% (336例),根据后循环的发育情况分为5个亚型：Ⅲa,18.9%（97例）;Ⅲb,32.2% (165例);Ⅲc,2.5% (13例);Ⅲd,4.5% (23例);Ⅲe,7.4% (38例);Ⅳ型29.8% (153例),根据前、后循环的发育情况组合将Ⅳ型分为5个亚型：Ⅳa,21%（108例）; Ⅳb型,1.2%(6例);Ⅳc,1.6%(8例);Ⅳd型, 1.9% (10例);Ⅳe型,4.1% (21例)。 结论　CTA是一种无创、有效的评价脑底动脉环类型的方法,利用CTA评价黔南地区少数民族脑底动脉环可以为其他与脑血管类型有关疾病提供正常对照;黔南少数民族地区对称型Willis环显示率较低,以Ⅲ型为主,Ⅳ型次之。     

多排CT血管成像显示脑循环血管变异研究进展

目的:探讨多排CT血管成像(MD-CTA)显示脑循环血管变异的价值.方法:查阅国内外相关文献,对各种脑循环血管变异影像学表现、发生率及临床意义进行总结分析.结果:脑循环血管变异包括:颅内动脉开窗和重复、Willis环变异、永存颈动脉-基底动脉吻合、颅底部动脉变异等.有些与动脉瘤形成有关,具有重要临床意义.结论:MD-CTA可检出大多数脑循环血管变异,有利于颅内动脉瘤、脑出血的检查和治疗计划的制定.     

Willis环各部分变异与脑梗死发生的相关性

目的:利用计算机断层扫描血管成像(CTA)技术探讨Willis环各部分变异与脑梗死发生的相关性。方法:回顾性分析新乡医学院第三附属医院住院患者,根据急性缺血性脑卒中诊断标准,分为脑梗死组和对照组,根据Willis环的完整性,分为Ⅰ型、Ⅱ型、Ⅲ型和Ⅳ型4种类型,分析2组中Willis环类型及各部分变异与脑梗死的相关性。结果:与对照组相比,脑梗死组Ⅰ型所占比例较低,Ⅳ型比例较高,前交通动脉变异率差异有统计学意义,余部分变异率差异无统计学意义;前交通动脉变异与脑梗死发生有关,脑梗死组前交通动脉变异与前交通动脉正常的比值是对照组的3.176倍。脑梗死组左右两侧大脑前动脉交通前段变异率差异有统计学意义,余部分左右对比无明显差异。结论:Willis环前交通动脉变异与脑梗死的发生有密切相关性,是脑梗死的危险因素。     

黔南少数民族正常成人脑动脉多层螺旋CT数据三维重建与相关解剖学分布

目的:了解黔南州少数民族正常人脑动脉多层螺旋CT血管成像(MSCTA)上主要脑动脉的起始部走行、形态及其分支的显示情况,测量起始部内径的正常值范围,观察脑底动脉环解剖结构及变异,为脑血管疾病的诊断及治疗提供参考资料。方法:选择500名健康体检者行全脑血管64层MSCTA检查,采用西门子signo工作站,经三维重建后测量各主要动脉起始部内径,观察其走行、形态和变异,并统计各级分支的显示率。结果:黔南少数民族正常人脑动脉的常见的变异发生在组成脑底动脉环的大脑前动脉A1段、前后交通动脉及大脑后动脉起始段,以后交通动脉变异最大。正常脑动脉Willis环分型,Ⅰ型为3%;Ⅱ型为1%;Ⅲ型为54%;Ⅳ型为42%。结论:黔南少数民族正常人脑血管变异主要发生于脑底动脉环,主要变异为Ⅲ型和Ⅳ型。     

16排螺旋CT血管成像对34例颅内动脉瘤的临床诊断分析

目的:分析34例颅内动脉瘤患者应用16排螺旋CT血管成像技术进行诊断的效果。方法:搜集我院2014年12月到2016年12月间经磁共振血管造影(Magnetic resonance angiography,MRA)、数字减影血管造影(Digital subtraction angiography,DSA)证实颅内动脉瘤患者34例,由一名副主任医师、两名主治医师对34例患者CT血管造影图像与MRA、DSA图像进行对比分析。结果:在34例患者中,有32例患者显示为颅内动脉瘤,2例MSCTA诊断阴性,诊断准确率94.12%。MSCTA能清楚显示颅内1-4级脑血管分支结构,同时可清楚显示动脉瘤的完整形态和空间结构。在32例颅内动脉瘤患者中,前循环动脉瘤18例,后循环动脉瘤14例;合并蛛网膜下腔出血26例,合并脑梗死3例。发现大脑后动脉、后交通动脉起始部、前交通动脉变异合计7例。结论:在34例颅内动脉瘤患者诊断中应用16排螺旋CT血管成像技术,能清楚显示颅内动脉瘤大小、形态、毗邻解剖关系以及Willis动脉环变异情况,可获得与DSA相近的检查结果,为患者手术或介入治疗提供有价值的参考,值得应用。     

64排螺旋CT扫描数据三维重建肝动脉及其解剖变异

目的 探讨肝动脉解剖变异情况及其临床意义。 方法 采用自行设计软件MIPS三维重建66例螺旋CT扫描数据中的肝动脉,根据Michels分型标准进行解剖变异分型。 结果 三维重建肝动脉形态逼真、立体感强。正常型40例,占60.61%;变异肝动脉26例,变异率为39.39%;未列入Michels分型的少见变异5例,占7.58%。 结论 肝动脉三维模型可以立体显示其解剖变异的各种类型。     

64层螺旋CT三维重建活体肝动脉的研究

目的：探讨64层螺旋CT应用于正常活体肝动脉研究的可行性，观察三维重建肝动脉的一般形态及走行规律。方法：选取行上腹部64-MSCT扫描检查的病例共153例，在智能追踪技术（smart prep）对腹主动脉腹腔干层面连续检测下，启动扫描。并将所得数据在GE ADW4.2工作站进行图像处理。结果：依据Michels标准153肝动脉分型如下：①I型，占80.4%（123例）；②II型，占2.0%（3例）；③III型，占　2.6%（4例）；④Ⅳ型，占2.0%（3例）；⑤V型，占4.0%（6例）；⑥VI型，占1.3%（2例）；⑦Ⅶ型，占1.3%（2例）；⑧Ⅷ型，无；⑨IX型，占2.6%（4例）；⑩X型，无。其他型，占4.0%（6例）不能归入Michels分型。结论：64层螺旋CT可以作为研究活体肝动脉形态的有效手段，三维重建能准确显示肝动脉的正常解剖类型和变异，对于活体肝动脉的研究有较好的临床应用价值。     

脑Willis环前循环动脉瘤的虚拟解剖研究

目的通过VR技术观测脑Willis环及相关动脉瘤的解剖数据,研究动脉瘤的发生与Willis环变异的关系。方法采集前循环动脉瘤患者头颅CT薄层血管扫描影像资料,在立体三维空间内观测并分析动脉瘤的发生与脑Willis环解剖变异的关系。结果 50例患者共57个动脉瘤VR环境下完成重建,三维空间内清晰直观的显示动脉瘤的解剖细节;50例患者Willis环左侧ACA-A1平均管径明显大于右侧;前交通动脉瘤患者ACA-A2夹角为(141.6±19.79)°,非前交通患者夹角为(113.68±16.73)°;12例PCoA-AN患者有7例胚胎型PCA。结论脑血管形态学类型不同是动脉瘤形成的重要因素。VR虚拟解剖较传统尸体解剖相比,具有重复利用性强、避免破坏尸体标本及立体三维解剖研究等独特优势。     

Patterns of reinnervation of denervated cerebral arteries by sympathetic nerve fibers after unilateral ganglionectomy in rats

Summary In order to clarify the manner in which previously denervated cerebral arteries become reinnervated after unilateral excision of the superior cervical ganglion (SCG), we observed directly the reinnervating sympathetic nerve fibers originating in the contralateral SCG by using anterograde labeling with wheat germ aggulutinin-horseradish peroxidase in rats. The nerve fibers sprouted from the nerve fibers in the contralateral anterior cerebral artery and reinnervated the arterial wall of the anterior cerebral artery of the denervated side as early as one week after ganglionectomy. In addition to this sprouting route, three other reinnervating nerve fiber routes were observed in the circle of Willis of the denervated side two weeks after ganglionectomy: the proximal portion of the internal carotid artery, the route passing between bilateral ethmodial arteries, and the posterior communicating artery. Eight weeks after ganglionectomy, these reinnervating nerve fibers formed a fairly dense plexus in a circular pattern in the circle of Willis. However, the reinnervation could not be observed in the arterial branches derived from the circle of Willis (middle cerebral artery and posterior cerebral artery) even 16 weeks after ganglionectomy. The present results clearly demonstrated the time course, distribution pattern and limitation of the reinnervation from the contralateral SCG following unilateral ganglionectomy. The fact that reinnervation could be observed only in the main cerebral arteries of the circle of Willis, in which the nerve plexus appeared to have a circular pattern, suggests a difference between the qualities of sympathetic innervation controlling the cerebral circulation in these arteries and the other arterial branches related to these differences in reinnervation capacity.     

大脑动脉环的解剖及在磁共振血管成像上的应用

目的探讨运用三维时间飞跃法(3D-TOF)磁共振血管成像显示大脑动脉环,为构建大脑基底动脉环三维可视化动脉图谱提供形态学资料。方法对10例尸体的大脑动脉环进行动脉间角度及距离的测量。同时,对30例正常人的头颅进行3D-TOF磁共振血管成像检查,图像经西门子Syngo B17工作站后处理,从影像学分析大脑动脉环。结果大脑前动脉显示率为100!,均表现为双支型。动脉环内的均值距离为(1.06±0.23)cm,其与颈内动脉间的均值夹角为(63.13±9.72)°,与前交通动脉的均值夹角为(107.95±57.70)°;颈内动脉环内段显示率为100!,其与大脑前动脉的均值夹角为(63.13±9.72)°,与后交通动脉的均值夹角为(123.20±10.37)°;大脑后动脉显示率为100!,动脉环内的均值距离为(0.56±0.12)cm,其与后交通动脉的均值夹角为(70.00±8.87)°,与基底动脉的均值夹角为(123.95±11.43)°;后交通动脉显示率为100%,动脉环内的均值距离(1.06±0.17)cm,其与颈内动脉的均值夹角为(123.20±10.37)°,与大脑后动脉的均值夹角为(70.00±8.87)°,与大脑中动脉的均值夹角为(131.15±15.21)°;前交通动脉的显示率为80%,动脉环内的均值距离为(0.23±0.16)cm,其与大脑前动脉的均值夹角为(107.95±57.70)°。结论明确了大脑动脉环的解剖组成,测量了动脉间的距离及动脉环内各动脉间的角度,3D-TOF法磁共振血管成像可清晰显示大脑动脉环的组成,三维重建技术可以从各个角度显示大脑动脉环。     

Overall distribution of vasoactive intestinal polypeptide-containing nerves on the wall of cerebral arteries: an immunohistochemical study using whole-mounts

The overall distribution of vasoactive intestinal polypeptide (VIP)-like immunoreactivity on the wall of the cerebral arteries, including its 3-dimensional profile, was investigated by means of the indirect immunofluorescence method using flat-mounts. VIP-immunoreactive fibers run spirally on the wall of the cerebral arteries. On the wall of the large arteries, such as the vertebral artery, basilar artery, internal carotid artery, within and/or without the circle of Willis, posterior and anterior communicating arteries, proximal parts of anterior, mid and posterior cerebral arteries, these fibers are richly distributed and show a dense grid-like appearance. The highest density was identified on the wall of the anterior cerebral artery, internal carotid artery and anterior communicating artery, while the lowest density was on the posterior communicating artery. On the other hand, on the walls of the branches of these arteries or along distal parts of the anterior, mid and posterior cerebral arteries, the number of VIP-immunoreactive fibers decreased markedly.     

Study of anomalies in the circle of Willis using magnetic resonance angiography in north eastern India

IntroductionThe circle of Willis is a large arterial anastomotic ring present at the basal cistern of the brain, uniting the internal carotid and the vertebrobasilar system. Branches from this arterial ring are distributed to supply the brain. In the year 1664, Sir Thomas Willis was the first to describe the importance of the circle in maintaining collateral flow. It was observed that there is very little mixing of blood between the collateral branches of the circle. These collaterals may however open up during occlusive episodes of the proximal feeding vessels. The anatomy of the circle is known to vary considerably and functionally a complete circle is a rare finding. This type of incomplete or variant forms off the circle may diminish its role as a collateral route.MethodsThe morphological pattern of circle of Willis of 70 healthy individuals from northeast India was studied retrospectively using Time of Flight-Magnetic resonance angiography (TOF-MRA).ResultsOnly 17 (24.28%) MRA's presented with a complete (classic) circle of Willis. Most common variant observed in our study was unilateral hypoplastic posterior communicating artery (20%). Most common variant observed in the anterior circulation was unilateral hypoplastic A1 segment of anterior cerebral artery (11.42%).DiscussionMost of the variant forms observed were comparable with earlier established findings. This variability (rare patterns) can be distinguished from an anomalous architecture if correlated phylogenically and embryologically.     

An Experimental Investigation of the Hemodynamic Variations Due to Aplastic Vessels Within Three-Dimensional Phantom Models of the Circle of Willis

A complete circle of Willis (CoW) is found in approximately 30–50% of the population. Anatomical variations, such as absent or surgically clamped vessels, can result in undesirable flow patterns. These can affect the brain’s ability to maintain cerebral perfusion and the formation of cerebral aneurysms. An experimental test system was developed to simulate cerebral physiological conditions through three flexible 3D patient-specific models of complete and incomplete CoW geometries. Flow visualizations were performed with isobaric dyes and the mapped dye streamlines were tracked throughout the models. Three to seven flow impact locations were observed for all configurations, corresponding to known sites for aneurysmal formation. Uni and bi-directional cross-flows occurred along the communicating arteries. The greatest shunting of flow occurred for a missing pre-communicating anterior (A1) and posterior (P1) cerebral arteries. The anterior cerebral arteries had the greatest reduction (15–37%) in efferent flow rates for missing either a unilateral A1 or bilateral P1 segments. The bi-directional cross-flows, with multiple afferent flow mixing, observed along the communicating arteries may explain the propensity of aneurysm formation at these sites. Reductions in efferent flow rates due to aplastic vessel configurations may affect normal brain function.     

自发性高血压大鼠脑底动脉含神经肽Y、含降钙素基因相关肽、含P物质神经的变化

用免疫组织化学（ＡＢＣ）方法，观察了含ＮＰＹ、含ＣＧＲＰ和含ＳＰ神经在自发性高血压大鼠脑底动脉的变化．结果表明，和对照用的京都Ｗｉｓｔａｒ大鼠相比，含ＮＰＹ神经在脑底动脉环吻侧的密度略低，而尾侧略高；自发性高血压大鼠大脑前动脉和大脑后动脉含ＮＰＹ神经纵行纤维密度比对照大鼠低，而环行纤维密度比对照大鼠高．自发性高血压大鼠脑底动脉含ＳＰ和含ＣＧＲＰ神经的密度均比对照大鼠低．本文对上述变化的意义进行了讨论．关键词