弥散加强成像对静脉性脑梗死诊断价值

Value of diffusion weighted imaging in diagnosing venous cerebral infarction

目的观察静脉性脑梗死的扩散加权成像(DWI)影像表现,比较DWI与T2WI的敏感性。方法回顾性分析32例经MR或DSA确诊的脑静脉窦血栓(CVST)患者的影像资料,所有患者全部伴有静脉性脑梗死。所有患者均在症状后1~48h行首次T1WI、T2WI、DWI、MRV序列检查。其中,25例进行了DSA检查。观察DWI和T2WI发现高信号梗死区的数量。并测量梗死区的表观扩散系数(ADC值)。结果静脉性脑梗死的急性期,DWI敏感性为90%,高于T2WI(32%)(P<0.05)。静脉性脑梗死的亚急性期DWI的敏感性为24%低于T2WI(100%)(P<0.05)。急性期静脉性梗死区的ADC值为5.32±1.03×10^(-4)mm^2/s低于亚急性期的ADC值(11.48±3.13×10^(-4)mm^2/s)(P<0.05)。结论 DWI对诊断静脉性脑梗死有补充价值。在静脉性脑梗死的急性期,DWI序列的作用突出,此时T2WI敏感性较低。通过测量梗死区的ADC值,我们能判断静脉性脑梗死中脑水肿的性质。

Objective To observe the representation of venous cerebral infarction in diffusion weighted imaging（ DWI）,and to compare the sensitivity of DWI and T2 WI. Methods We performed a retrospective analysis of 32 patients with venous infarction proved by MR or DSA. All the patients were performed with T1 WI,T2WI,DWI and MRV sequences in acute period. In these cases,25 patients were examined with DSA. We observed the number of hyperintense infarct area in DWI and T2 WI and measured the ADC value in infarct zone. Results The sensitivity of DWI sequence to detect infarction was estimated at 90%,which was higher than that of T2 WI at acute stage. But the sensitivity of DWI sequence was lower than that of T2 WI at subacute stage. The ADC value of infarct zone at acute stage was smaller than that of the subacute. Conclusion DWI appears to be of additional diagnostic value in venous cerebral infarction. The DWI sequence may be particularly useful during the cute phase of venous cerebral infarction when the sensitivity of T2 WI is low. By measuring the ADC value of infarcted area,we can define the type of edema in venous cerebral infarction.