中文摘要：

目的探讨急性脑梗死患者MR早期增强T1WI中脑实质强化及大脑中动脉高信号（HMCA）征与继发性脑出血（HT）的关系。方法回顾性分析24例发病6．0h内[平均（4．3±1．4）h]的急性脑梗死患者首次T1WI及随后1周内复查的MRI和（或）CT资料，了解首次增强T1WI脑实质强化和HMCA征与HT的关系。早期脑实质强化为脑梗死6．0h内缺血的脑组织区域在增强T1WI出现高信号；HMCA征为增强T1WI上大脑中动脉增粗（与对侧相比）、出现边缘模糊的高信号。结果24例患者中10例发展为HT（出血组），其中6例首次T1WI可见脑实质强化，5例出现HMCA征；14例未出现HT（无出血组），均未发现脑实质强化和（或）HMCA征。2组相比，T1WI脑实质强化、HMCA征出现率差异均有统计学意义（P值均〈0．01）。结论T1WI早期脑实质强化和HMCA征有可能预测急性脑梗死后HT。

英文摘要：

Objective To investigate the relationship among early parenchymal enhancement, post-gadolinium （Gd） hyperintense middle cerebral artery （HMCA）, and subsequent hemorrhagic transformation （HT） in patients with hyperacute ischemic stroke. Methods Twenty-four consecutive patients with ischemic stroke who underwent MRI within 6 h [ （ 4. 3 ± 1.4 ） h ] of symptom onset were retrospectively reviewed. All of these patients underwent at least one follow-up MRI or non-enhanced CT study at 2 to 7 days. Post-Gd T1WI were analyzed for parenchymal enhancement and hyperintense MCA. Gradient echo MRI and CT were used for assessment of HT. Results Ten patients developed HT on follow-up imaging （hemorrhagic group）. Early parenchymal enhancement was found in 6 patients with HT （P 〈0. 01 ）. The HMCA was in 5 patients with HT （ P 〈 0. 01 ）. In the fourteen patients without HT （ nonhemorrhagic group）, none showed early parenchymal enhancement and/or hyperintense MCA. Conclusions Early parenchymal enhancement and HMCA on T1WI after Gd-DTPA administration are independent predictors of subsequent HT.