磁敏感加权成像界定卒中急性期缺血半暗带及与灌注加权成像的对照研究

摘要

Objective To evaluate whether susceptibility weighted imaging (SWI) can be used in definition of penumbra during acute stage of cerebral infarction,compared with perfusion weighted imaging (PWI).Methods Ischemic stroke patients within 3 days after onset were included.They adopted multimodal magnetic resonance imaging examination,including regular magnetic resonance imaging sequence (T1 WI,T2 WI and T2-weight fast fluid-attenuated inversion-recovery),diffusion weighted imaging (DWI),PWI and SWI.Alberta Stroke Programme Early CT Score was done on DWI,SWI and PWI.The mismatch of SWI-DWI (minimal indensity projection (mIP)-DWI) was compared with that of PWI-DWI (mean transit time (MTT)-DWI) and analyzed statistically.The application of prominent vein (PV) on SWI as a sort of alternation of cerebral blood volume (CBV) and direct observation of thrombosis in arteries on SWI were done.Results The SWI-DWI (2.39 ± 1.42) and the MTT-DWI (2.72 ± 1.49) mismatch showed no statistically significant difference (r =0.726,P ＞ 0.05).The grade of PV was positively related with the CBV of the ipsilateral brain tissue on admission (r =0.564,P ＜ 0.05).SWI showed the similar ability with magnetic resonance angiography to judge responsible blood vessels with susceptibility vessel sign.Conclusion SWI-DWI can evaluate the ischemic penumbra.PV may reflect the increased blood volume of the lesion side of the brain tissue.SWI can reveal the thrombosis of the responsible vessels.%目的 评价磁敏感加权成像(susceptibility weighted imaging,SWI)能否在急性缺血性卒中急性期尽早界定缺血半暗带,并与灌注加权成像(perfusion weighted imaging,PWI)对照观察其临床应用价值.方法 收集2012年1月至2013年1月就诊于吉林大学第一医院神经内科、确诊为脑梗死的患者18例.在患者发病3d内对其完成多模式头颅MRI检查,包括弥散加权成像(diffusionweighted imaging,DWI)、PWI、SWI、Tl WI、T2WI、液体衰减反转恢复序列像等,并分别进行DWI、SWI、PWI的阿尔伯特早期CT评分(ASPECTS).将最小密度投影(minimal indensity projection,minIP)-DWI即SWI-DWI的不匹配范围和平均通过时间(mean transit time,MTT)-DWI即PWI-DWI的不匹配范围进行比较,评价SWI在卒中早期判定半暗带的价值.并观察利用SWI序列的扩张静脉替代脑血容量直接观察血管内的血栓的临床意义.结果 (1) SWI-DWI (2.39±1.42)和MTr-DWI (2.72±1.49)不匹配范围相当,二者在评估缺血半暗带的作用上差异无统计学意义(r=0.726,P＞0.05).(2)扩张静脉等级与患侧脑组织脑血容量呈正相关(r =0.564,P＜0.05).(3)以磁共振脑血管造影作为参照标准,在SWI上发现的血管磁敏感征可以用以判断责任血管.结论 在缺血性卒中急性期,SWI-DWI可以评估缺血半暗带范围,扩张静脉可以反映病变侧脑组织血容量,SWI还可用于判定责任血管.