脑出血和出血性脑梗死磁共振扩散加权成像

目的 探讨非缺血性脑中风的扩散特性及其影像表现。方法 25例缺血性脑梗塞患者。22例脑内血肿患者和5例混合性脑中风患者采用MRI常规扫描和进行扩散成像(DWI)和表现扩散成像(ADC)。重点分析脑出血和出血性脑梗塞的DWI和ADC的表现。结果 25例急性脑梗死DWI表现为高信号区域，ADC表现为低信号区；脑内血肿患者，其中1例超急性和2例急性期血肿DWI上呈高信号，ADC呈低信号；8例亚急性早期DWI呈低信号，3例亚急性中晚期DWI呈高信号，其ADC均呈低信号；4例慢性早期DWI中央呈高信号，周边呈低信号环，ADC呈低信号；4倒慢性后期DWI呈低信号，2例ADC呈低信号，2例ADC呈稍高信号。5例混合性脑中风DWI既有梗死的高信号，又有不同时期血肿的稍低和低信号。结论 DWI能反映不同脑中风的扩散特性，血肿的DWI还与其演变成分相关。DWI对脑血管意外的检测具有重要意义。

Diffusion-weighted Imaging of MRI in Acute Cerebral Stroke

Objective To analyze the diffusion properties of acute cerebral stroke to understand the effects of infarct and hematoma on diffusion-weighted MR images of patients with acute cerebral stroke. Methods 25 acute cerebral infarcts, 22 intracranial hematomas and 5 hemorrhagic infarctions were studied with CT, conventional and diffusion MR imaging. The DWI and ADC parameters of acute cerebral stroke were analyzed. Results The DWI images of 25 acute cerebral infarcts, 1 hyperacute hematoma, 2 acute hematomas and 3 subacute hematomas were hyperintensity, and that of 8 early subacute hematomas were hypointensity. The DWI images of early stage of 4 chronic hematomas were hyperintensity at center and hypointensity at periphery, and that of late stage were hypointensity. The DWI images of acute hemorrhagic infarctions had both the hyperintensity and hypointensity. Meanwhile, the ADC images of majority of the lesions were hypointensity. Conclusion DWI could reflect the diffusion properties of different types of cerebral strokes and play an important role in evaluating the strokes.