64层螺旋CT减影血管成像诊断脑动静脉畸形的价值

目的：探讨64层螺旋CT减影血管成像诊断脑动静脉畸形（AVM）的价值。材料和方法：26例脑AVM患者,均经64层螺旋CT平扫、增强动脉期和静脉期扫描。将动脉期数据减去平扫数据获得减影动脉期数据,静脉期数据减去动脉期数据获得减影静脉期数据,静脉期数据减去平扫数据获得减影混合动静脉期数据。采用容积再现（VR）、最大密度投影（MIP）重建脑血管图像。结果：本组病例减影脑血管图像均去除了颅骨的干扰,清楚显示大小不等的畸形血管巢及供血动脉和引流静脉。畸形血管巢位于颞叶7例,顶叶5例,额叶5例、枕叶6例和小脑半球3例。发现供血动脉39支,其中单支供血动脉15例,多支供血动脉9例;引流静脉33支,单支引流10例,多支引流16例。结论：64层螺旋CT减影血管成像可以去除颅骨干扰,显示AVM的供血动脉、畸形血管巢和引流静脉,为临床治疗方案的制定及术后随访提供可靠的依据。     

CTA减影技术在脑动静脉畸形诊断中的应用价值

目的:探讨CTA减影技术对于脑动静脉畸形的诊断价值。方法:采用64层螺旋CT行头部或头颈部CTA,回顾性分析21例确诊的脑动静脉畸形患者CT、CTA表现。结果:减影CTA图像上,21例患者病变显示率约为95%,20例患者显示典型的畸形血管团,表现为迂曲成团状、蜂窝状、巢状、结节状、窦状、网状影;1例小脑半球畸形血管显示不典型,为片状影。20例患者有明确的供血动脉,其中18例为单支供血,2例为双支供血;21例患者病灶中均有明确的引流静脉,引流静脉可直接入静脉窦,也可通过增粗的大脑浅静脉引流到相应的静脉窦。结论:CTA减影技术诊断脑动静脉畸形可行、有效,值得在临床上推广使用。     

CT减影技术诊断脑动静脉畸形的临床应用

目的 评价64排螺旋CT减影CT血管造影技术诊断脑动静脉畸形(AVM)的临床价值.方法 17例脑AVM患者行64排螺旋CT减影CT血管造影检查,对畸形血管团的数目、位置、范围、供血动脉的分布及引流静脉的方向等进行统计分析.结果 本组病例中减影CTA共发现17个病灶,与DSA和手术所见比较,1个直径1.2 cm的病灶被漏诊.减影CTA诊断脑AVM的敏感度、特异度及准确度分别为94.4%、100%、94.4%.减影CTA在显示细小供血动脉的清晰程度低于DSA,其判断脑AVM供血动脉的敏感度为83.0%.减影CTA对引流静脉的显示与DSA影像和手术所见一致. 结论 64排螺旋CT减影CTA可作为评价脑AVM的检查方法.     

64层螺旋CT血管造影在脑血管疾病中的应用

目的 探讨64层螺旋CT血管造影在脑血管疾病诊断中的应用价值.方法 53例脑血管病变患者行64层螺旋CT脑血管造影检查.先行平扫,后行CTA扫描,并用减影法进行后处理,重建得到VR、MIP、MPR及CPR图像,综合分析多种图像评价脑血管病变.结果 动脉瘤患者11例,其中颈内动脉至大脑中动脉瘤1例,颈内动脉瘤2例,大脑中动脉瘤2例,小脑上动脉瘤1例,后交通动脉瘤2例,前交通动脉瘤2例,基底动脉瘤1例,所有瘤体及瘤颈均得到清晰显示.动静脉畸形2例,均能显示畸形血管团,其中1例清晰显示供血动脉及引流静脉,另1例仅能显示引流静脉,供血动脉显示不清.脑血管狭窄或闭塞40例,均显示脑血管不同程度节段性、局限性狭窄或闭塞.结论 64层螺旋CT血管造影运用减影技术并综合多种重建方法能快速、准确诊断脑血管病变,有良好的临床应用价值.     

多层螺旋CT在肺隔离症诊断中的应用

目的 探讨多层螺旋CT在肺隔离症诊断中的应用.方法 收集经手术及病理证实的32例肺隔离症患者的资料进行回顾性分析,所有检查采用GE Brightspeed 16层螺旋CT扫描机,先行CT平扫,再行双期增强扫描,将图像传输至工作站,进行MPR、MIP、SSD及VR重建.结果 32例肺隔离症均位于下叶后基底段,其中27例位于左下肺,5例位于右下肺.异常供血动脉16例来自胸主动脉,7例来自腹主动脉,3例系膈肌动脉供血,4例为肋间动脉供血,2例为脾动脉供血.CT平扫主要表现为肺内囊肿、结节或肿块,增强扫描病变区血管影增多增粗,呈条状或结节状血管强化影.结论 多层螺旋CT增强及三维重建是诊断肺隔离症最理想的无创性检查方法.     

多层螺旋CT脑血管造影容积显示技术成像的临床应用

目的 探讨多层螺旋CT脑血管造影容积显示(VR)成像的临床应用价值。资料与方法 36例疑脑肿瘤或脑血管病患者行多层螺旋CT脑血管造影术，准直1mm，层厚1．25mm，应用VR技术进行三维重建。结果 全部病例均经DSA或手术病理证实，其中正常3例；脑肿瘤19例，包括13例脑膜瘤，4例听神经瘤，2例颅咽管瘤；脑动脉瘤6例；脑血管畸形8例。VR图像可清晰明确地显示多血供肿瘤的大小、形态及与脑血管和颅骨的三维关系；能明确脑动脉瘤的部位、大小及瘤颈宽度；可准确显示血管畸形的大小、形态以及供血动脉、引流静脉的数量。结论 多层螺旋CT脑血管造影VR成像能清晰明确地显示颅内病变与血管间的解剖关系，可为临床提供更多信息并对手术有指导意义。     

DSA对脑动静脉畸形出血的预测分析

目的:探讨脑动静脉畸形(AVM)血管造影形态与出血关系,预测脑动静脉畸形(AVM)出血的危险性。方法:回顾性分析104例数字减影脑血管畸形资料。结果:穿支动脉供血、单支引流和深部引流、小病灶及位于基底节和后颅窝者易出血。结论:通过观察脑动静脉畸形(AVM)供血动脉(类型)、大小、位置、引流静脉数目及通畅情况,可以对脑动静脉畸形(AVM)的出血情况进行预测。     

64层螺旋CT脑动脉造影方法研究

目的:探讨应用64层螺旋CT进行脑动脉造影(CTA)检查扫描的最佳时相和方法,优化图像后处理,为脑动脉畸形及脑动脉瘤等脑血管病变提供可靠的依据。方法:使用西门子公司Sensation 64层螺旋CT及后处理工作站,应用相应的4D后处理软件及血管对比剂自动跟踪触发扫描软件(BOLUS软件)。选取临床诊断蛛网膜下腔出血及怀疑脑血管畸形的患者38例,采用Bolus跟踪与目测颈动脉对比剂浓度相结合的方法进行脑动脉CT造影检查。结果:38例患者中达到诊断标准34例,扫描失败3例,经延迟补救扫描后成功1例,其中6例行DSA造影,5例符合,1例行DSA造影时未发现动脉瘤,再行CTA检查确切检出动脉瘤。符合率83.3%。结论:使用64层螺旋CT,采用BOLUS跟踪与目测颈动脉对比剂浓度相结合的方法进行脑动脉CT造影检查可准确区分脑动-静脉血管,在诊断脑血管疾病方面可以作为常规方法使用。     

环状强化征象在鉴别脑内血肿与脑脓肿时的价值

造影增强CT扫描时,脑脓肿表现环状强化,但无特异性,此表现也见于脑转移,神经胶质瘤,血肿和出血性脑梗塞。作者报道2例环状强化,初诊为脑脓肿,后证实为动静脉血管畸形所致的脑内血肿。例1增强CT扫描示右额叶有一环状强化病变。脑血管造影示右额叶有异常血管团,与CT扫描病变部位一致。例2增强CT扫描示右额叶有一环状强化病变。脑血管造影示右额叶有异常血管团及一条引     

脑动静脉畸形的破裂出血与其动脉供血系统的关系

本文对经过脑血管造影及手术证实的１１０例脑ＡＶＭ进行回顾性分析，探讨了脑ＡＶＭ破裂出血与其动脉供血系统的关系。本文结果显示：供血动脉轻度扩张（Ｐ＜０．０１）、供血动脉主干较短（Ｐ＜０．００１）及动脉供血系统合并动脉瘤的（Ｐ＜０．０１）脑ＡＶＭ出血率高。我们认为在制定脑ＡＶＭ治疗方案时，要考虑其供血动脉的特点。     

磁敏感加权成像在脑血管畸形显像中的初步应用研究

目的 初步分析磁敏感加权成像(SWI)在脑血管畸形显像中的应用价值. 资料与方法 2006年5月至9月间对11例颅内血管畸形患者资料进行前瞻性研究,11例中男7例,女4例,平均年龄25岁.其中6例为海绵状血管瘤,3例为脑动静脉畸形,2例为静脉畸形.SWI所得图像应用10 mm厚度的最小密度投影重组.与手术所见和DSA对比,将SWI图像与常规MR序列比较. 结果 SWI对11例血管畸形患者的病灶均显示清楚.其中6例海绵状血管瘤患者常规MR序列发现10个海绵状血管瘤,而SWI发现了15个;3例脑动静脉畸形患者中,2例SWI较常规序列发现更多病灶.SWI发现了DSA所见的4支引流静脉中的3支,而常规MR序列仅可以显示1支,且更易与动脉区分,常规序列和SWI均可发现2支供血动脉,SWI还可以显示其中1例动静脉畸形的钙化; 2例静脉畸形均可清晰显示扩张的髓静脉和粗大的引流静脉,而常规序列显示欠佳. 结论 SWI应作为脑血管畸形尤其慢流速血管畸形诊断的常规序列应用于临床,结合其他序列对脑血管畸形能提供更全面、精确的信息.     

Morphologic characteristics of subcortical heterotopia: MR imaging study

BACKGROUND AND PURPOSE: Gray matter heterotopia have been divided into three groups based on clinical and imaging characteristics: subependymal, subcortical, and band heterotopia. Nonetheless, subcortical heterotopia can have variable morphologic findings. The purpose of this study was to perform a morphologic analysis of a series of cases of subcortical heterotopia based on MR images, to correlate the morphologic appearance with clinical characteristics, and to speculate about the embryologic implications of our results. METHODS: The MR imaging studies and clinical records of 24 patients with subcortical heterotopia were retrospectively reviewed. The morphologic findings of the heterotopia were recorded along with presence and type of associated malformations. These results were correlated with available data on development and neurologic status. RESULTS: Analysis revealed that, in six cases, the heterotopia were composed exclusively of multiple nodules, in 13, they appeared primarily as curvilinear ribbons of cortex extending into the white matter, and in five, they had deep nodular regions with curvilinear areas more peripherally. All of the curvilinear regions were contiguous with the cerebral cortex in at least two locations. In eight cases, curvilinear heterotopia contained curvilinear areas of flow void that were thought to be blood vessels; in 10, they contained fluid resembling CSF. No difference in developmental or neurologic manifestations was noted among patients with heterotopia of different morphologic appearances. CONCLUSION: Subcortical heterotopia can have nodular or curvilinear morphologic appearances. Although no difference was found in the clinical conditions of the patients with differing morphologic appearances, additional analysis of these patients or studies of animal models of these malformations may further our understanding of normal and abnormal brain development.     

Measurements of diagnostic examination performance and correlation analysis using microvascular leakage,cerebral blood volume,and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

Introduction  

To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades.     

Use of acetazolamide-challenge xenon CT in the assessment of cerebral blood flow dynamics in patients with arteriovenous malformations

Arteriovenous malformations (AVMs) may cause symptoms related to a reduction of cerebral blood flow (CBF) to surrounding brain parenchyma. To evaluate this compromise of hemodynamic reserve (commonly referred to as steal phenomenon), we used acetazolamide challenge and stable-xenon CT (Xe/CT). Baseline Xe/CT studies in 13 patients with AVMs were followed by an acetazolamide challenge to the vascular reserve. Blood flow maps were quantitated by using region-of-interest (ROI) software. ROI findings were categorized into four groups on the basis of the presence or absence of normal baseline CBF and presence or absence of normal augmentation of CBF. ROIs were designated as near site (within the vascular territory supplying the AVM) or far site (outside the vascular territory supplying the AVM). One patient had a normal baseline and normal augmentation of CBF (group 1). The other patients had a combination of one or more of the other three categories. Ten patients had parenchymal areas that exhibited either a normal or low baseline CBF with decreased augmentation; both conditions were interpreted as decreased vascular reserve (groups 2 and 3). Eleven patients had parenchymal areas that showed a low baseline CBF and normal augmentation with acetazolamide (group 4), interpreted as having a decreased demand for CBF but having a normal vascular reserve. Decreased vascular reserve was found in 27% of the nearsite areas and 17% of the far-site areas. No patients had only far-site abnormal vascular reserve. We believe that compromised vascular reserve can best be evaluated with a challenge study, such as this acetazolamide-challenge Xe/CT study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Angiography and computed tomography in the evaluation of cerebral venous malformations

Summary The information obtained by computed tomography (CT) and cerebral angiography is compared in eight cases of cerebral venous malformation. Angiography was found to be more reliable for detecting the presence and specific nature of these malformations. Pathological and radiographic differential features between the various forms of cerebral vascular malformations are discussed.     

Cerebral blood flow: assessment with dynamic contrast-enhanced T2*-weighted MR imaging at 1.5 T

The authors assessed regional cerebral blood flow dynamics with magnetic resonance (MR) imaging enhanced with gadolinium diethylenetriaminepentaacetic acid (DTPA). After bolus administration of Gd-DTPA, rapid T2*-weighted gradient-echo images were acquired. Image acquisition time ranged from 2 to 3 seconds. The signal intensity (SI) of brain tissue and blood vessels markedly decreased during the first pass of contrast agent through the brain due to the local field inhomogeneity caused by the concentrated paramagnetic contrast agent. The method was used in 18 subjects with no cerebrovascular disease and 32 patients with stroke, vascular stenosis, arteriovenous malformation, and cerebral neoplasm. Comparison with intracranial angiography was performed in three patients and with single-photon emission computed tomography of blood flow in four. The change in T2* relaxation rate was approximately linearly related to the dose of contrast agent. The SI change increased as the echo time was lengthened. Regions in cerebral infarcts, metastases, and arteriovenous malformations showed different enhancement patterns than those of edema around a lesion and of normal brain tissue. Abnormal circulation times in patients with vascular stenoses were demonstrated. The method provides information about cerebral blood flow dynamics not available from conventional MR imaging and MR angiography.     

口腔颌面部高血流量型血管畸形的经导管栓塞治疗

目的探讨超选择经导管动脉栓塞治疗口腔颌面部高血流量型血管畸形的方法和疗效。方法18例患者中8例行外科术前经导管介入栓塞术,患者均在介入栓塞后72h内行外科切除术;另10例行经导管动脉栓塞根治术,均在全面头颈部血管造影后将微导管超选至供血动脉,注入PVA等栓塞剂栓塞畸形血管团。结果18例患者均超选择插管栓塞治疗成功,技术成功率100%,均未发生皮肤黏膜坏死、颅内动脉误栓塞等严重并发症。术前介入栓塞治疗的8例患者在外科切除术中出血量明显减少,肿块切除变易,手术时间缩短。实施介入栓塞根治术的10例患者,其中1次栓塞治愈者5例,经2次栓塞治愈者4例,3次治愈者1例。经术后1～24个月随访肿块均明显缩小,器官功能改善。结论经导管超选择动脉栓塞治疗口腔颌面部高血流量型血管畸形效果显著,安全、方便。     

脑小血管畸形的CT诊断

收集我院１９８４至１９９３年经手术病理证实６０例脑血管畸形，其中２３例脑小血管畸形，占３８％，全部病例经ＣＴ检查，部分追加脑血管造影。文中总结脑小血管畸形常见和不常见ＣＴ表现，提出多数通过ＣＴ增强检查能作出诊断。分析易误诊病例，并作了鉴别诊断。     

Metabolic and hemodynamic evaluation of gliomas using positron emission tomography

Positron emission tomography (PET) was used on 16 patients with untreated cerebral gliomas to measure cerebral glucose and oxygen metabolism, oxygen extraction, blood flow, and blood volume. In addition, pH values were obtained for seven cases. Gliomas were later proven by biopsy; two patients had tumors with degrees of malignancy of grade II, two patients had grade III, and 12 patients had grade IV tumors. Compared with homologous gray matter regions in the opposite hemisphere, tumor tissue showed increased blood volume, but decreased oxygen extraction and oxygen metabolism. Compared with grade II tumors, grade IV tumors demonstrated higher blood volumes, but lower relative oxygen extraction and utilization. Tumor blood flow was variable, but was lower in the higher grade tumors. Rates of glucose utilization in tumor, calculated by using individually determined rate constants, were variable, and did not correlate with tumor size or tumor grade. Parietal tumors (n = 6) tended to have higher relative glucose utilization and blood flow, and lower relative oxygen extraction, when compared with frontal tumors (n = 4). Tumor pH differed significantly from the pH in contralateral brain (p less than 0.005); alkalotic pH values were consistently seen. These findings in and around cerebral gliomas studied before intervention differ from the results found in gliomas after exposure to radiation or chemotherapy.     

Cerebral blood flow evaluation of arteriovenous malformations with stable xenon CT

Twenty patients with supratentorial arteriovenous malformations (AVMs) were evaluated with angiography, conventional CT, and stable xenon CT to determine cerebral blood flow. Contralateral and ipsilateral regions of interest relative to the AVM were evaluated from cerebral blood flow maps and correlated with angiography. A significant decrease in cerebral blood flow was observed in the ipsilateral cortical gray matter adjacent to the AVM relative to the corresponding contralateral cortex (mean difference = 9.52 ml/100 g/min, p less than .01). The larger AVMs (greater than 8 cm3) were associated with a more marked decrease with a mean difference of 12.22 ml/100 g/min (p less than .02). Regions of interest were also chosen on the basis of angiographic findings, which suggested areas of decreased flow. Comparison of these areas with analogous contralateral areas also showed a significant decline in cerebral blood flow (mean difference = 8.86 ml/100 g/min); this decline was greater with larger AVMs (volume greater than 8 cm3), which had a mean difference of 11.38 ml/100 g/min (p less than .01). Our correlative study enabled us to pinpoint the regions most likely to have reduced flow from an AVM.