DWI及ADC图对脑梗死病情进展的评估作用研究

目的:研究核磁共振弥散加权成像及表观弥散系数图像对脑梗死的病情进展和恢复状态的评估作用。方法:对一组超急性期(8例)和急性期(10例)脑梗死患者连续追踪行T_1-FLAIR、FSE-T_2WI、T_2-FLAIR、DWI序列扫描检查,及ADC图像重建,观察不同期相脑梗死灶的图像特征,计算其固定层面病灶区域残余弥散积(MSAFSS):面积×(3.0-1 000×ADC),并使其与相应的脑功能损害评分相对应,进行相关性分析。结果:①超急性期病灶,T_1-FLAIR、T_2WI均无明显信号改变,T_2-FLAIR偶可见等或稍高信号,DWI则可见明显的高信号,ADC图为低信号;急性期梗死灶,T_1-FLAIR基本都呈低信号改变,T_2WI表现为高信号,T_2-FLAIR为高信号,DWI仍为高信号,ADC图为低信号;亚急性期病灶,T_1-FLAIR信号较前都明显降低,T_2WI、T_2-FLAIR、DWI均为高信号表现,ADC图为稍低或等信号表现;慢性期病灶,T_1-FLAIR为低信号,T_2WI为高信号,T_2-FLAIR、DWI呈低或等信号,而ADC图为高信号。②对12例全程追踪的观察结果显示,病灶全过程的MSAFSS与评分分值之间无相关(P0.05);而亚急性早期前10例的MSAFSS与分值间具有正相关性(P0.05)。结论:各期脑梗死在DWI及ADC图上都有其不同的图像特征,并可据此大体判断脑梗死所处期相;通过计算MSAFSS可以对亚急性早期以前的脑梗死病情进展与功能恢复状态给予一定程度的评估。

Magnetic resonance diffusion weighted imaging and apparent diffusion coefficient mapping in evaluation of development of cerebral infarction

Objective： To investigate the evaluation of cerebral infarction development by diffusion weighted imaging and appar- ent diffusion coefficient map of MR. Methods： A group of cases with cerebral infarction （8 in superacute stage and 10 in acute stage） were scanned with T1-FLAIR, FSE-Tz WI, Tz-FLAIR, DWI of MR for several times in different stages, the characters of the different stages were observed and the multiplication of square and the left ADC of focus in stable slice （MSAFSS）-Iesion focus squareX （3-1000 X ADC） was measured and computed in order to test the relationship between MSAFSS and score of NIHSS in the same time. Results： @As for superacute cerebral infarction, there was no signal change on T1-FLAIR and T2 WI, and few focus showed little high signal on T2-FLAIR. All focuses showed high signal on DWI and low signal on ADC map. As for acute cerebral infarction, focus showed low or equal signal on T1-FLAIR, low signal on ADC map, and high signal on all of the T2WI, T2-FLAIR, DWI series. As for subacute cerebral infarction, focus showed obviously low signal on T1- FLAIR, equal or low signal on ADC map, high signal on T2WI, T2-FLAIR, and DWL As for chronic cerebral infarction, focus showed low signal on T1-FLAIR, high signal on T2WI and ADC map, low or equal signal on T2-FLAIR and DWI. （2）As far as the 12 cases were concerned which were followed up during all stages, there was no relationship between MSAFSS and score of NIHSS for the whole course of cerebral infarction （ P 〉0.05） by statistical test, but as for 10 of the 12 cases, there was some positive relation between them if only for the case early before its subacute stage （ P d0.05）. Conclusion： Cerebral infarction in different stage has different characters on DWI and ADC mapping, by which the stage was confirmed. MSAFSS （the multiplication of square and the left ADC of focus in stable slice） can reflect the course of cerebral infarction before early subaeute stage.