脑梗死后磁共振弥散加权成像信号强度时间演变规律及其诊断价值  

Time course of signal intensity changes on diffusion-weighted MRI after cerebral infarction and its diagnostic value

作　　者：荣良群[1] 魏秀娥[1] 张涛[1] 朱本亮[1] 杨森[1] 龚爱平[1] 高丽[1] 许静[1] 

机构地区：[1]徐州医学院第二附属医院神经内科,江苏徐州221006

出　　处：《徐州医学院学报》2007年第9期581-583,共3页Acta Academiae Medicinae Xuzhou

基　　金：徐州市科学技术局计划项目(X2005234)

摘　　要：目的探讨脑梗死后磁共振弥散加权成像（DWI）信号强度演变规律及其在脑梗死诊治中的价值。方法对27例临床确诊的超急性期（〈6 h）脑梗死患者行常规磁共振和弥散加权成像扫描,并分别于脑梗死的急性期（6～72 h）、亚急性期（4～14天）和慢性期（15～30天）进行3次磁共振随访,观察脑梗死后不同时间DWI信号强度的变化。结果①脑梗死超急性期：DWI呈高信号改变,高信号病灶阳性率为91.1%;常规磁共振T1WI和T2WI均无阳性病灶发现。②脑梗死急性期：DWI信号仍为高信号,高信号病灶阳性率为100%;T1WI、T2WI病灶阳性率为82.2%、86.7%。③脑梗死亚急性期：DWI仍呈高信号,高信号病灶阳性率为97.8%;T1WI和T2WI病灶阳性率均为100%。④脑梗死慢性期：DWI信号大多呈等信号和低信号改变,高信号病灶阳性率仅为22.22%;T1WI和T2WI病灶阳性率均为100%。结论脑梗死病灶信号在DWI呈现一定的时间演变规律;DWI对于诊断超急性期及急性期脑梗死明显优于常规磁共振,亚急性期两者相似,慢性期DWI不如常规磁共振;DWI结合常规磁共振可以用于判断不同时期脑梗死。Objective To investigate the time course of signal intensity changes on diffusion - weighted MRI （DWI） after cerebral infarction and its diagnostic value. Methods Both conventional MRI and DWI were performed in 27 patients with superacute cerebral infarction. The MRI observations were carried out consecutively at acute （6 -72 h）, snbacnte （3 -14 d） and chronic （15 -30 d） stages to investigate the dynamic changes of the infarction. The change in signal intensity of the infarct lesions on DWI was observed. Results ①In the hyperacute stage, DWI showed hyperintensity in 91. 1% of the lesions. No positive lesions were found on the conventional weighted MR images T1WI and T2WI.②In the acute stage, infarcts still showed hyperintensity on DWI, the rate of hyperintensity was 100%, higher than 82.2% and 86.7% for T1WI and T2WI respectively. ③ In the snbacnte stage, the characters of signal intensity became reversed, with the positive rate of hyperintensity lesions being 97.8% on DWI, about equal to the 100% on T1WI and T2WI. ④In the chronic stage, the lesions would show isointensity or hypointensity on DWI, with the positive rate of hyperintensity lesion on DWI become down to 22.2% only. Conclusion There is a specific time course of signal intensity changes after cerebral infarction on the DWI. DWI can better describe the lesions in the hyperacute and acute stages than the conventional MRI, but DWI is not as good as MRI in identifying the chronic lesions. Hence, DWI combined with conventional MRI would be advised to identify the cerebral infarction at different stages.

关 键 词：脑梗死 磁共振成像 弥散加权成像 

分 类 号：R743.3[医药卫生—神经病学与精神病学]