磁共振弥散加权成像联合灌注加权成像技术在诊断不同时期老年脑梗死的临床价值

Clinical value of combined magnetic resonance DWI and PWI in diagnosis of cerebral infarction at different stages

目的探讨弥散加权成像(DWI)联合灌注加权成像(PWI)诊断不同时期脑梗死的临床价值。方法选择在我院住院治疗的168例老年脑梗死患者,将按发病时间分为超急性期(发病时间≤6h)32例,急性期(发病时间7~72h)64例,亚急性期(发病时间73h^10d)45例和慢性期(发病时间11~15d)27例。患者进行DWI和PWI检查,比较2种检查所得头部核磁图像的参数差异和异常区域差异。结果超急性期患者和急性期患者患侧脑组织DWI中表观弥散系数(ADC)值显著低于健侧脑组织(0.39±0.08 vs 0.83±0.03;0.32±0.07 vs 0.91±0.05,P<0.01),而亚急性期患者和慢性期患者患侧脑组织DWI中ADC值显著高于健侧脑组织(1.54±0.34 vs 0.85±0.07;2.01±1.29 vs 0.90±0.05,P<0.01)。不同分期患者PWI均表现为脑血流量和脑血容量降低,而平均通过时间和达峰时间延长。信号异常区域DWI<PWI的多见于超急性期患者,DWI>PWI的多见于急性期患者,DWI=PWI的多见于亚急性期和慢性期患者。结论 PWI可显示脑梗死患者的缺血半暗带,DWI则可凸显出脑梗死病灶,两者联合运用可反映不同时期脑梗死患者脑组织血流状态,为临床治疗提供参考。

Objective To stuy the clinical value of combined DWI and PWI in diagnosis of cerebral infarction（CI）at different stages.Methods One hundred and sixty-eight elderly CI patients were divided into hyperacute phase group（n=32）,acute phase group（n=64）,subacute phase group（n=45）and chronic phase group（n=27）.Their DWI and PWI parameters and abnormal brain regions were compared.Results The ADC on DWI for injured lateral brain tissue was significantly lower than that on DWI for unjured lateral brain tissue in hyperacute phase group and acute phase group（0.39±0.08 vs 0.83±0.03;0.32±0.07 vs 0.91±0.05,P〈0.01）.However,the ADC on DWI for the injured lateral brain tissue was significantly higher than that on DWI for the uninjured lateral brain tissue in subacute phase group and chronic phase group（1.54±0.34 vs 0.85±0.07,2.01±1.29 vs 0.90±0.05,P〈0.01）.The PWI showed that the CBV was smaller and the CBF was slower while the MTT and TTP were longer in CI patients at different stages.DWI〈PWI,DWI〉PWI,and DWI=PWI in abnormal signal region were more frequently detected in hyperacute phase,acute phase subacute phase and chronic phase respectively.Conclusion PWI can show ischemic penumbra while DWI can highlight infarct foci in CI patients.Combined PWI and DWI can display the CBF in CI patients at different stages,and can thus provide reference for the clinical treatment of CI.