弥散加权成像对超急性脑缺血的临床应用研究  

Clinical Study of Hyperacute Cerebral Ischemia on MR-DWI

作　　者：曾文兵[1] 石安兵[1] 汪明全[1] 

机构地区：[1]万州区重庆三峡中心医院,重庆404000

出　　处：《实用医技杂志》2006年第17期2953-2958,共6页Journal of Practical Medical Techniques

基　　金：重庆市万州区科委立项研究课题;重庆市万州区科技人才专项资金资助项目(编号2005411)。

摘　　要：目的:运用磁共振弥散加权成像(DWI),研究超急性脑缺血及脑梗死前期的影像特征及细胞水肿的分子影像学基础,界定缺血半暗带(IP),评估其在临床治疗中的应用价值。方法:将在6h内首次发病且疑似缺血性脑中风患者56例先行16层CT扫描,排除脑出血后再经MRI系列成像检查,判断有无超急性脑梗死,界定IP组织,将符合溶栓适应证的患者进行溶栓治疗,余皆进行神经保护治疗,并对照分析其疗效。结果:CT显示颅脑正常37例,脑出血5例,陈旧性梗死9例,具有超急性脑梗死征5例。MRI系列检查51例中,T1WI、T2WI显示轻微脑肿胀和脑动脉流空征消失7例;FLAIR显示缺血高信号灶9例;DWI除5例短暂性脑缺血发作(TIA)显示正常外,余46例均表现为与临床体征一致的高信号责任灶,ADC图呈低信号,其敏感性显著优于CT及MRI常规检查;MRA显示病灶区供血动脉阻塞、变细、局部狭窄或远端分支减少。磁共振灌注成像(PI)显示48例有异常灌注缺损,其异常灌注体积(vPI)与DWI异常信号体积(vDWI)不一致:30例vPI>vDWI,界定具有IP1组织;10例vPI=vDWI及6例vPI<vD-WI,考虑缺乏IP1组织;5例TIA患者中2例显示微循环灌注异常,提示PI能敏感地反映脑梗死前期的影像特征;临床观察:将12例溶栓治疗患者与34例单纯神经保护治疗者进行临床及MRI随访,前者疗效明显优于后者,神经功能显著改善,IP缩小。对比分析46例经治疗后最终梗死灶体积(vCI)与发病时vDWI有明显差异:35例vCI<vDWI,认定具有IP2组织,提示DWI上高信号可能代表梗死核心和缺血半影区;6例vCI>vDWI梗死面积扩大,5例vCI=vD-WI,考虑缺乏IP2组织;追踪随访TIA患者有2例发展为脑梗死。结论:DWI能够在超急性脑梗死组织发生不可疑损伤之前明确诊断,并能在活体状态下深入到细胞毒性水肿分子水平,DWI与PI的联合应用对于IP的确定、临床溶栓治疗的选择以及挽救缺血脑组织具有重大的作用,且Objective To study the imaging characteristics of superactue cerebral ischemia and molecular imaging basis of cytotoxic edema, to determine the ischemie penumbra （IP）, and to assess the application value in the clinical treatment by using diffusion-weighted imaging （DWI）. Methods 56 patients who were suspected ischemic stroke within 6 hours were scanned CT, then routine MRI sequences,FLAIR, DWI and magnetic resonance perfusion imaging（PI）. To compare the volume of vDWI, vPI, vCI and define the IP. Some match the indication were given the thrombolysis treatment and others were given only neuroprotective treatment. Results Imaging analysis：CT show 37 cases are normal, 5 cases are cerebral hemorrhage, 9 cases are chronic infarction,and 5 cases are hyperacute cerebral infarction. 51 cases are taken MRI examination, and 7 cases show slightly cerebral swelling and artery flow void sign on routine T1WI and T2WI;9 cases show is chemic high signal intensity on FLAIR,9 cases of chronic infarction; on DWI except for 5 cases with transient ischemic attack（TlA） show normal appearance,other 46 cases show high signal intensity lesions which consistent with clinical signs,on ADC maps they show hypointensity,the sensibility of DWI superior to CT and routine MRI examinations. MRA show artery of the lesion is obstructed, tipped and focal stenosis or decreasing of distal branches; PI shows that 48 cases have abnormal perfusion defect,in which there are 2 patients with TIA, indicating that PI is more sensible to reflect perfusion status of microcirculation in ischemic cerebral tissue and can reflect the imaging characteristics of cerebral infarction in the early stage on a certain extant; contrast analysis of abnormal signal volume on DWI（vDWI） and PI（vPI） ： 30 cases vPI〉 vDWI, considered to have IP; tissues ; 10 cases vPI= VDWI and 6 cases vPI〈 vDWI,considered to lack of IP; tissue. Clinical observation：contrast analysis between 12 cases which match the indication and were given the thrombolysis tre

关 键 词：磁共振成像 弥散加权成像 脑缺血 溶栓 

分 类 号：R743.31[医药卫生—神经病学与精神病学]