经颅多普勒诊断脑血管痉挛的对比分析
2009-05-06马凤春
马凤春
【摘要】 目的 通过应用经颅多普勒(TCD)检测蛛网膜下腔出血患者的颅内血流状况,诊断脑血管痉挛(CVS)并经过数字减影血管造影(SDC)证实,说明TCD诊断CVS的可靠性。方法 应用TCD检测2000-2005年CT已经明确诊断为蛛网膜下腔出血Ⅰ~Ⅲ级患者49例(Ⅳ~Ⅴ级患者病情严重不宜做血管造影检查,因此不做讨论)。于患病后第1天开始,每隔3 d监测一次,动态观察10 d。观察血管参数:大脑中动脉(MCA)、颈内动脉终末段(TICA)、颈内动脉颅外段(ICA)的收缩期峰值流速(Vs)、平均血流速度(Vm)以及大脑中动脉与颈内动脉颅外段(ICA)峰值流速的比值(∨MCA/∨ICA),同时行SDC检查证实。结果 49例患者中,TCD提示CVS者26例,痉挛条数33条。数字减影血管造影结果显示CVS者31例,痉挛条数36条,TCD诊断CVS的敏感率为83.8%,TCD诊断CVS特异性为91.6%。结论 TCD技术与SDC相比具有操作简便、价廉、实时无创、敏感有效,容易重复检查等优点。
【关键词】 经颅多普勒;脑血管痉挛;数字减影血管造影
Transcranial Doppler in diagnosis of cerebral vasospasm-A comparative study
MA Feng-chun.Beijing Miyun County Hospitail,101500,China
【Abstract】 Objective The purpose of this study is to evaluate intracranial blood flow conditions in patients with subarachnoid hemorrhage with transcranial Doppler (TCD),and to investigate the reliability of TCD in diagnosis of cerebral vasospasm (CVS) by comparing with the subtraction digital angiography (SDC) result.Methods 49 patients who underwent TCD examination between 2000 and 2005 were involved in this study.All the patients had appearance of subarachnoid hemorrhage for grade Ⅰ~Ⅲ on computerized tomography (CT) scan (grade Ⅳ~Ⅴ were excluded because too serious to endure angiography).From the first day of making a definite diagnosis,TCD were performed every three days,and the observation lasted for ten days.Evaluated parameters included:The Peak and mean velocity(Vs and Vm)of Middle cerebral artery(MCA),Distal internal carotid artery(TICA)and Extracranial internal carotid artery(EICA).Ratio of MCA and EICA(VMCA/VICA) was calculated,and SDC for each person were also performed.Results Among the 49patients,TCD suggested 26 were CVS,and 33 vasospasm vessels in total.SDC results showed there were 31CVS patients,and 36 vasospasm vessels in total.Specification of TCD in CVS diagnosis was 83.8%,and the specification was 91.6%.Conclusion Compared with the SDC,TCD has its advantages for flexible operations,low cost,real-time and non-invasive,sensitive and effective,and good reproducibility.
【Key words】 Transcranial Doppler;Vasospasm;Subtraction digital angiography
CVS是脑出血、 蛛网膜下腔出血和重度颅脑损伤的严重并发症,严重的CVS可以引起脑缺血、脑梗塞及神经功能障碍,甚至死亡,因此早期诊断CVS非常重要。
1 资料与方法
1.1 研究对象 选择本院2000-2005年期间,已经明确诊断的蛛网膜下腔出血的患者49例,发病时间均在24 h之内开始观察。根据Hunt-Hess分级,Ⅰ级6例;Ⅱ级15例;Ⅲ级28例;Ⅳ~Ⅴ级患者病情严重不宜做血管造影检查,因此不做对比分析。其中男26例,女23例,年龄38~65岁。
1.2 仪器和方法 应用美国麦迪根500M经颅多普勒,平卧位,应用2 MHz脉冲多普勒探头和4 MHz连续脉冲多普勒探头分别经双侧颞窗和颈部探测MCA、TICA和ICA的收缩期峰值速度、平均血流速度,并计算∨MCA/∨ICA的比值。经颞窗探测深度45~65 cm。于患病后第1天开始,每隔3 d观察一次,动态观察10 d,记录每个患者最高峰值流速和最高平均流速,做为诊断参数。观察血管参数:MCA、ICA、TICA的Vs、Vm、MCA与ICA峰值流速的比值(∨MCA/∨ICA)。依据国内常用痉挛诊断标准):Vm 90~120 cm/s诊断为轻度痉挛;Vm 120~150 cm/s诊断为中度痉挛;Vm>150 cm/s诊断重度痉挛,∨MCA/∨ICA>3也是诊断CVS的辅助指标之一。同期患者行数字减影血管造影检查,两种检查结果进行对比分析。
2 结果
49例患者中,仅MCA血流速度增高者11例;仅TICA流速增高者5例;MCA和ICA同时增高者10例,其中MCA的Vm最高者148 cm/s、Vm最低者91 cm/s;TICA的Vm最高者136 cm/s、Vm最低者90 cm/s同时伴有∨MCA/∨ICA>3者23例,提示脑血管痉挛者26例,痉挛条数33条。另外23例患者在观察期间,血流速度虽然存在较大波动,但是未能达到诊断痉挛的标准。数字减影血管造影结果显示脑血管痉挛30例,痉挛条数36条,TCD观察CVS的敏感率为86.7%,TCD诊断CVS特异性为94.2%。
3 讨论
脑血管痉挛的发生多是由于颅内出血所致的血凝块,释放出各种活性物质。如5-HT、儿茶酚胺、血红蛋白及花生四烯酸代谢产物的缩血管作用,引起血管的收缩,另外机械刺激损伤部位的脑血管,也会引起脑血管收缩导致痉挛的发生。临床上将SDC检查作为诊断脑血管痉挛的金标准,但是SDC操作过程复杂,耗时,而且会对脑血管造成很大的刺激,甚至加重痉挛的发生。而且TCD技术与SDC相比具有操作简便、价廉、实时、有效无创,容易重复检查等优点,其准确性和敏感性很高,应用TCD检测不仅可以早期诊断脑血管痉挛,并指导临床调整用药剂量,选择手术时机,在很大程度上减少了后遗症和死亡率。
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