表观弥散系数评价脑内病变周围水肿性质的价值

THE VALUE OF APPARENT DIFFUSION COEFFICIENT IN ASSESSMENT OF CHARACTERS OF PERILESIONAL EDEMA IN DIFFERENT BRAIN DISEASES

目的探讨表观弥散系数(ADC)值对脑内不同病变周围水肿区性质鉴别的价值。方法对脑转移瘤30例、脑胶质瘤26例(其中病理Ⅲ～Ⅳ级21例)、脑脓肿20例病人行常规磁共振成像(MRI)及弥散加权成像(DWI)检查,部分同时行增强MRI检查。所有病人脑内病变周围水肿区最大长度≥10mm,按水肿距病变的远近将其平均分成近侧水肿区和远侧水肿区,分别测其ADC值;同时测量对侧对应正常脑白质区ADC值,计算近、远侧水肿区相对ADC(rADC)值。结果脑转移瘤近侧水肿区rADC值明显高于脑胶质瘤、脑脓肿周围近侧水肿区,差异有显著性(F=3.12,P<0.05);三者远侧水肿区rADC值差异无显著性(F=1.36,P>0.05)。脑转移瘤周围近侧水肿区rADC值明显高于远侧rADC值,差异有显著性(t=2.068,P<0.05);脑胶质瘤周围近、远侧水肿区rADC值分别与脑脓肿周围近、远侧水肿区比较差异无统计学意义(t=-1.068、1.302,P>0.05);脑胶质瘤与脑脓肿周围近、远侧水肿区的rADC值比较均差异无统计学意义(t=0.935、-0.433,P>0.05)。结论 rADC值在脑胶质瘤、脑转移瘤及脑脓肿周围水肿区性质判定方面有一定价值。

Objective To assess the value of apparent diffusion coefficient（ADC） in differentiation of the character of perilesional edema of different intracranial diseases. Methods Seventy-six patients with brain diseases（30 metastatic brain tumors,26 gliomas including 21 Ⅲ-Ⅳgrade glioma,and 20 brain abscess） underwent routine and diffusion-weighted MR imaging,meanwhile,some patients underwent enhanced MRI.The greatest length of perilesional edema in all the patients was ≥10 mm,which was then divided into two areas： proximal and distal edema,the ADC values were measured in the two areas,and that in corresponding normal alba were detected as well.The rADC values of proximal and distal edema areas were calculated. Results The value of rADC in proximal edema area in metastatic tumor was markedly higher than that in glioma and brain abscess,the differences between them were significant;in distal edema area,the differences of rADC values among them were not significant.In metastatic tumor,the rADC in proximal edema area was higher than that in distal area,the difference being significant（t=2.068,P〈0.05）;in glioma,the values of rADC in both proximal and distal area were not significantly different compared with that of brain abscess（t=-1.068,1.302;P〉0.05）.In glioma and brain abscess,their values of rADC in proximal area versus distal area were not statistically different（t=0.935,-0.433;P〉0.05）. Conclusion The rADC have a certain value in determining the nature of perilesional edema caused by glioma,metastatic tumor and brain abscess.