Three-dimensional computed tomographic angiography with low loads of contrast agent in acute subarachnoid hemorrhage

In the pre-operative evaluation of aneurysmal subarachnoid hemorrhage (SAH), three-dimensional computed tomographic angiography (3D-CTA) is very helpful. However, it is usually difficult to perform 3D-CTA following four-vessel cerebral angiography in the setting of acute SAH because of high loads of contrast agent. The present report is designed to enable 3D-CTA following catheter angiography for surgical planning. Fourteen consecutive patients with acute SAH underwent four-vessel cerebral angiography. After identification of the aneurysm, all patients were moved to the CT room next to the angiography room under catheterization. Contrast agent (10 ml) was diluted with 40 ml of heparinized saline. This diluted contrast agent was then injected through intra-arterial catheter for 3D-CTA. 3D-CTA with diluted contrast agent which was injected through intra-arterial catheter revealed sufficiently clear images. In addition, this method could provide anatomical information that was not readily available from catheter angiography. 3D-CTA with additional low dose of contrast agent can immediately follow four-vessel cerebral angiography in the setting of acute SAH. No complications were noted throughout the procedures. It has been our experience that the imaging modality in combination with not only catheter angiography but also 3D-CTA is advantageous in case of acute SAH and provides better detail for surgical planning.     

Whole brain CT perfusion combined with CT angiography in patients with subarachnoid hemorrhage and cerebral vasospasm

Objective

To assess cerebral vasospasm (CVS) and monitor cerebral microcirculatory changes in patients with acute subarachnoid hemorrhage (SAH) via CT angiography (CTA) combined with whole-brain CT perfusion (CTP) techniques.

Methods

Sixty patients with SAH (SAH group) and 10 patients without SAH (control group) were selected for a prospective study. CTP combined with CTA and digital subtraction angiography (DSA) studies were performed on patients with initial onset of SAH less than three days. CTA and DSA as well as the CTP parameters such as cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) were acquired and analyzed. The relationship of CTA and CTP measurements was assessed in these acute SAH patients.

Results

CTP techniques were used to achieve the perfusion maps of the whole brain in patients with acute SAH. Compared to the control group, mean CBF value was significantly lower while both MTT and TTP values were significantly higher in SAH group (all p < 0.05). Further analysis revealed that mean CBF in patients with CVS, sCVS, Fisher III–IV and Hunt–Hess III–V significantly decreased when compared to patients with nCVS, asCVS, Fisher I–II and Hunt–Hess I–II (p < 0.05). Furthermore both MTT and TTP values were also significantly reduced in patient with CVS, sCVS, Fisher III–IV and Hunt–Hess III–V (p < 0.05).

Conclusion

The study demonstrated that changes of microcirculation in patients with SAH could be assessed by whole-brain CTP. CTP combined with CTA could detect both macroscopic evident vasospasm on CTA and alterations of microcirculation on CTP. Mean CBF was significantly lower in patients with SAH.     

Dynamic single-section CT demonstrates reduced cerebral blood flow in acute intracerebral hemorrhage

Optimum blood pressure (BP) management in acute intracerebral hemorrhage (ICH) remains controversial. BP reduction may limit hematoma expansion, but may also exacerbate ischemia. Reduced regional cerebral blood flow (rCBF) has been reported in ICH. Its extent and precise pattern, however, remain uncertain. Dynamic single-section CT perfusion (CTP) is rapid, easily performed and offers superior spatial resolution to PET, SPECT and MRI. It may be the most applicable method for assessing the effects of BP management on rCBF in ICH. We sought to assess whether CTP can identify rCBF abnormalities in acute ICH in 5 patients with ICH who underwent CTP within 24 h of symptom onset. rCBF was measured in serially expanded 2-mm rings around the hematoma and compared with rCBF in the uninvolved hemisphere. Mean time to CTP was 9 h (range 3-23). Mean ICH volume was 25 ml (range 9-64). Perihematoma perfusion was reduced in all patients compared with contralateral hemisphere rCBF. rCBF reduction was most pronounced immediately adjacent to the hematoma (p < 0.05 at 2 mm, p = 0.084 at 4 mm, p > 0.2 at 6 and 8 mm). Perihematoma rCBF increased as a function of the distance from hematoma perimeter. Rate of rCBF increase over distance correlated with time from onset (p = 0.006). We conclude that CTP identifies a rim of reduced rCBF in ICH. A gradient of hypoperfusion appears to extend at least 4 mm beyond the hematoma edge and may be time dependent. Whether reduced CBF is associated with perihematoma ischemia requires additional study.     

颅脑CT血管成像对判断急性脑梗死患者预后的价值

目的 探讨颅脑CT血管成像(CTA)对判断急性脑梗死(ACI)患者预后的价值.方法 对70例发病≤6 h ACI患者进行颅脑CTA检查,并评价患者入院时、出院时美国国立卫生研究院卒中量表 (NIHSS) 评分和改良的Ranking量表(mRS)评分.结果 CTA检查显示血管正常32例,大血管闭塞38例.血管闭塞组患者出院时NIHSS评分和mRS评分均高于无血管闭塞组,差异有统计学意义 (P<0.01,P<0.001);两组出院时NIHSS评分、mRS评分均比入院时明显降低(均P<0.001).无血管闭塞组患者预后良好25例(78.1%),血管闭塞组预后良好17例(44.7%),两组差异有统计学意义(P<0.01).入院时NIHSS评分及CTA显示的血管状况与临床预后呈负相关(r=-0.25,P<0.05;r=-0.73,P<0.001),入院时NIHSS评分(OR 0.09, 95%CI: 0.07～0.12, P<0.01)和血管是否闭塞(OR 0.12, 95%CI: 0.01～0.24, P<0.05)与预后有关,是ACI预后的独立预测因素.无血管闭塞组患者进行溶栓或未溶栓治疗的预后良好比率(分别为66.7%、75.0%)差异无统计学意义(P>0.05).血管闭塞组溶栓治疗患者预后良好比率(58.8%)明显高于未溶栓治疗患者(31.8%)(P<0.05).结论 血管闭塞的ACI患者预后较差,CTA对判断ACI患者的预后及选择溶栓治疗有意义.     

Three-dimensional CT angiography of central nervous system]

Three-dimensional CT angiography (3 D-CTA) has become a modality of choice for the evaluation of the lesions and diseases of central nervous system. Further enhancement of diagnostic capability has been achieved by the development and introduction of multislice CT, which enabled us to obtain true isotrophic volumetric data. Most proven application of 3 D-CTA in CNS is the diagnosis and management of cerebral aneurysms. It can be used as an alternative to conventional angiography in most of cases. Other promising applications of 3 D-CTA are, pre-surgical evaluation of arteriovenous malformations, diagnosis of ischemic diseases, and evaluation of neck artery.     

蛛网膜下腔出血脑血管造影假阴性原因分析

目的 探讨蛛网膜下腔出血(SAH)脑血管造影假阴性发生的可能原因,提高SAH病因诊断的准确性.方法 回顾性分析452例SAH患者的脑血管造影结果初次阴性52例,复查造影25例,发现6例有异常病变:4例前交通动脉瘤,1例C<,2>段动脉瘤,1例脑血管畸形.结果 结合文献对这6例初次脑血管造影假阴性的原因进行分析,总结发生假阴性的原因.结论 SAH造影时应采用高分辨率的造影机;二维造影时要多角度投射,避开血管间的重叠;必要时采用三维血管重建;提高阅片医生的能力;初次阴性病例可配合CTA、MRA检查且必须强调全面细致复查造影.     

CT脑血管造影在急性脑血管性疾病诊疗中的应用

CT脑血管造影术(computed tomographic angiography, CTA)是随着CT技术的发展,通过浅静脉注入造影剂来显示脑血管性病变的一种新的影像学检查手段,因其具有无创、快速、显像清晰等优点,近年来在临床上逐步得到广泛应用.我院自1999年开展此项技术以来取得了良好效果,现总结汇报如下.     

三维CT对颈内动脉硬膜环附近动脉瘤的诊断

目的总结应用三维CT血管造影(3D-CTA)对颈内动脉硬膜环附近动脉瘤(juxta-dural ring aneurysm, JDRAn)的诊断经验。方法分析23例该部位动脉瘤患者的26个动脉瘤与海绵静脉窦及硬脑膜的位置关系,评价3D-CTA在判定动脉瘤是否向硬膜内突出上的作用。结果3D-CTA诊断出26个JDRAn中的25个,诊断率为96%。仅在高CT值表面遮盖显示法(shaded surface display,SSD)处理影像上显示的6个动脉瘤均位于硬膜外;6个颈内动脉窦部动脉瘤(carotid cave aneurysm, CCAn)中3个位于硬膜内,1个位于硬膜外,另2个颈部的一部分突出于硬膜内。低CT值处理影像上显示的其它13个非CCAn均突出于硬膜内。结论3D-CTA可以有效地诊断JDRAn,为手术适应证的选择提供有益的参考。     

CTA在出血性脑动静脉畸形救治中的应用价值

目的探讨三维计算机断层摄影血管造影(3D-CTA)在出血性脑动静脉畸形诊断及术前评估中的应用价值。 方法选择自2007年3月至2011年2月收治的破裂脑动静脉畸形患者19例,对所有患者均行头颅CTA检查,并经DSA对照检查、手术证实。 结果首次CTA检查发现14例阳性,其中急诊直接行开颅血肿清除+畸形血管团切除4例,术后复查CTA及DSA提示全切除;3例首次CTA及DSA检查均为阴性,1年后CTA复查发现异常血管团,经DSA检查证实后手术治疗;2例首次及2周后CTA检查阴性,但DSA检查示小型畸形血管团。 结论CTA因其快捷有效、无创伤、安全等优点,尤其适合于出血性脑动静脉畸形的急诊检查,能充分显示脑动静脉畸形三维结构的特点可为手术入路提供良好的依据。     

CT脑灌注与血管造影在急性缺血性脑卒中的临床应用与分析

目的探讨CT脑灌注(CTPI)与血管造影在急性缺血性脑卒中中的临床应用价值。方法选择29例急性缺血性脑卒中患者为研究对象,采用东芝Aquilion 64排CT行头颈部CTA及CTPI检查,观察两者对急性缺血性脑卒中诊断情况,分析CTPI与CTA对急性缺血性脑卒中诊断的一致性。结果①29例患者CT灌注图上发现与临床症状相对应的灌注异常区共25例,阳性率为86.2%(25/29),高于普通CT扫描的27.6%(8/29),差异具有统计学意义(P0.05)。②灌注异常区的CBF、CBV、MTT三组参数值与镜像健侧相比差异有显著统计学意义(P0.05);③CTA血管检查结果发现单纯颈内动脉狭窄5处;单纯颅内动脉狭窄10处;颈内动脉及颅内动脉均狭窄4例。④病例组CTPI联合CTA检查结果比较,病例组存在责任血管的患者CTPI检查阳性率为65.51%(19/29)高于无责任血管者的20.69%(6/29),差异具有统计学意义(P0.05)。结论 CTPI与CTA可以清晰的显示缺血性脑卒中脑内病灶及责任动脉,能够提高更多有价值的信息。     

CT对脑胶质瘤卒中与单纯脑出血鉴别诊断的辅助价值

目的 探讨CT在脑胶质瘤卒中与单纯脑出血鉴别诊断中的辅助价值.方法 回顾性分析河北医科大学附属以岭医院神经外科自2008年至2010年经手术和病理证实的12例胶质瘤卒中患者的临床和CT资料.结果 CT检查示11例均见境界清楚的高密度血肿:9例见肿瘤实体,3例未见明显瘤灶;灶周水肿10例.结论 仔细分析CT表现,增强扫描,并结合临床病史,有助于脑胶质瘤卒中与单纯脑出血的鉴别诊断.     

Anticoagulant-related hemorrhage in acute cerebral embolism

Five patients with nonseptic cerebral embolism of cardiac origin are reported in whom early anticoagulant therapy resulted in clinical deterioration or death from frank hemorrhage into the acute infarct. In each patient an initial CT scan excluded the presence of intracerebral hemorrhage and a second CT scan, after clinical deterioration had occurred, documented frank hemorrhage into the infarcted zone. All five patients had large infarctions in the right middle cerebral artery territory and three patients were mildly hypertensive. Four patients received heparin within 36 hours of their stroke and one was on warfarin at time of the embolism. Clinical deterioration occurred after intervals of several hours (2 cases), 5-6 days (2 cases) and 30 days (1 case). In only 2 patients was anticoagulant activity excessive at time of clinical deterioration. This report illustrates the danger of early anticoagulant therapy of acute nonseptic cerebral embolism, particularly in the setting of large infarction.     

64层螺旋CT对头颈部血管病变的临床价值探讨

目的探讨64层螺旋CT血管成像对头颈部血管病变的临床价值。方法34例疑头颈部血管病变的患者行64层螺旋CT头颈部血管成像(CTA),扫描数据在ADW 4.3工作站用不同的后处理技术进行血管后重建。结果34例患者的双侧颈内动脉(ICA)、椎动脉(VA)、大脑前动脉(ACA)、大脑中动脉(MCA)、大脑后动脉(PCA)及Willis环均能显示,共检出狭窄76段,闭塞2段,动脉瘤5例;血管异常起源3例,正常者14例。结论64层螺旋CT血管成像可以清晰显示头颈部血管病变,对临床诊疗起重要指导作用。     

64层螺旋CT灌注成像和血管成像在急性缺血性脑卒中的应用

目的：探讨64层螺旋CT 灌注成像（CTP）、CT血管成像（CTA）在急性缺血性脑卒中的应用价值。方法对30例急性缺血性脑卒中患者,于发病12 h内行头CT平扫、CTP、CTA检查,分析平扫及灌注CT表现,计算灌注缺损区CBF、CBV、MTT各参数值,与对侧相应区灌注参数进行比较,重建颈段和脑内动脉CTA图像,并于发病2～7 d复查CT平扫。结果30例急性缺血性脑卒中患者,15例C T平扫未发现异常,14例可见腔隙梗死灶或软化灶,1例可见脑梗死早期低密度改变。10例C T P未见明显异常,20例C T P发现与临床症状相对应的大小不等的灌注减低区,18例可见不同范围缺血半暗带。CTA 显示12例未见明显异常,18例可见血管狭窄或闭塞。结论 CTP、CTA能够快速准确反映缺血部位及范围,显示缺血半暗带,判断闭塞血管,对早期诊断急性脑梗死和指导溶栓治疗具有重要价值。     

CT血管造影阴性自发性蛛网膜下腔出血患者的处理

自2006年1月至2009年12月我院共收治自发性蛛网膜下腔出血(subarachnoid hemorrhage,SAH)患者645例,所有患者均首选CT血管造影(computed tomography angiography,CTA)检查,其中586例共发现颅内动脉瘤591个,12例为脑血管畸形、Moyamoya病等,47例CTA检查阴性,回顾性分析这     

Metabolic alterations in rabbit cerebral arteries caused by subarachnoid hemorrhage

The effect of subarachnoid hemorrhage on metabolic rates in rabbit cerebral arteries was investigated by measuring adenosine triphosphate (ATP) content and L-lactate release. The mean +/- SEM ATP content was 0.38 +/- 0.02 mumol/g wet wt in control rabbit basilar arteries (n = 6). The ATP content decreased significantly to 0.17 +/- 0.02 mumol/g wet wt 2 days after experimental subarachnoid hemorrhage (n = 6), although only a slight decrease was detected in the basilar arteries 2 days after cisternal injection of the same amount of artificial cerebrospinal fluid. Hypoxia significantly decreased ATP content in the control basilar arteries to 0.26 +/- 0.04 mumol/g wet wt (n = 6). The same degree of hypoxia did not decrease ATP content in the basilar arteries after subarachnoid hemorrhage. Release of L-lactate was significantly higher from the arteries after subarachnoid hemorrhage than from the control arteries under both aerobic and hypoxic conditions. Our results indicate that subarachnoid hemorrhage induced an alteration of metabolic rates in rabbit cerebral arteries. The oxygen-requiring pathways to synthesize ATP may be important in control cerebral arteries; however, after experimental subarachnoid hemorrhage, the main pathway in the cerebral arteries may shift from oxygen-requiring pathways to an anaerobic glycolytic pathway.