脑梗死磁共振弥散加权成像信号改变和近似弥散系数的时间演变规律

Cerebral Infarction: Time Course of Signal Intensity Changes and the Apparent Diffusion Coefficient Abnormality on MR Diffusion weighted Imaging

目的 :确定脑梗死磁共振弥散加权成像 (DWI)信号改变和近似弥散系数 (ADC)的时间演变规律。方法 :分析 10 1例脑梗死患者的 13 5次DWI资料。结果 :超急性、急性和亚急性期脑梗死DWI为高信号 ,慢性早期多数病灶仍为高信号 ,慢性晚期绝大部分病灶为等或低信号。超急性期、急性期和亚急性期脑梗死ADC下降 ,慢性早期多数病灶接近或高于正常 ,慢性晚期明显升高。结论 :脑梗死的DWI信号和ADC变化具有特征性的时间演变规律 ,结合常规MRI 。

Aim:To determine the time course of signal intensity changes and the apparent diffusion coefficient (ADC) abnormality on MR diffusion weighted imaging (DWI) after cerebral infarction. Methods:135 DWI in 101 patients were analyzed. Results:On DWI, all cerebral infarctions in hyperacute, acute and subacute stage and many of the lesions in early chronic stage manifested hyperintensity; but most of lesions manifested isointensity or hypointensity in later chronic stage. ADC reduced in hyperacute, acute and subacute stage; ADC pseudonormalized or elevated in early and later chronic stage.Conclusion:There were specific time course of signal intensity changes and the ADC abnormality after cerebral infarction on DWI, combined with conventional MRI, the stage of cerebral infarction could be estimated on DWI.