DTI对鉴别脑低级别胶质瘤、脑梗死和病毒性脑炎的价值

目的:探讨磁共振扩散张量成像在鉴别低级别脑胶质瘤、脑梗死和病毒性脑炎中的应用价值。方法:22例低级别脑胶质瘤、26例急性或亚急性期脑梗死和18例病毒性脑炎患者在治疗或手术前行常规MRI和DTI检查。脑低级别胶质瘤患者均经手术病理证实,病毒性脑炎和脑梗死患者均经临床治疗及随访证实。测量并计算3组病灶的表观扩散系数(ADC)值和相对表观扩散系数(rADC)值、各向异性分数(FA)值和相对各向异性分数(rFA)值,并进行统计学分析。结果:脑低级别胶质瘤组平均ADC、rADC、FA和rFA值分别为(1.55±0.08)×10-3 mm2/s、1.68±0.25、0.17±0.03和0.42±0.08,脑梗死组分别为(0.54±0.12)×10-3 mm2/s、0.64±0.12、0.14±0.03和0.30±0.05,病毒性脑炎组分别为(0.84±0.07)×10-3 mm2/s、1.07±0.05、0.17±0.02和0.43±0.09。三组病例的平均ADC值及rADC值间的差异有高度统计学意义(P<0.01),脑低级别胶质瘤与脑梗死的FA值和rFA值之间、病毒性脑炎与脑梗死的FA值和rFA值之间差异有高度统计学意义(P<0.01),脑低级别胶质瘤与病毒性脑炎的FA值和rFA值之间差异无统计学意义(P>0.05)。结论:综合利用DTI的ADC值、rADC值、FA值及rFA值,对鉴别脑低级别胶质瘤、脑梗死和病毒性脑炎具有较高的指导价值。

Diffusion tensor imaging in the differential diagnosis of low-grade cerebral glioma, cerebral infarction and viral encephalitis

Objective：To study the value of diffusion tensor imaging （DTI） in the differential diagnosis of low-grade cerebral glioma, cerebral infarction and viral encephalitis. Methods： Conventional MR imaging and DTI were performed in 22 cases with low-grade cerebral glioma,26 cases with acute or subacute cerebral infarction and 18 cases with acute or subacute viral encephalitis before treatment or surgery. The diagnoses of cerebral low-grade glioma was confirmed by surgery and pa thology,and the diagnoses of cerebral infarction/viral encephalitis were made by clinically follow-up. The apparent diffusion coefficient （ADC） value,relative ADC value （rADC）,fractional anisotrophy （FA） value and relative FA values （rFA） of the three groups were measured and calculated respectively. Results： The mean ADC values, rADC values, FA values and rFA values of the patients with low grade cerebral glioma was （1. 55±0.08）×10^3mm^2 /s,1. 68±0.25,0. 17±0.03, 0.42±0.08 respectively;of cerebral infarction was （0.54±0.12）×10^3mm^2/s,0. 64±0.12,0.14±0. 03,0. 30±0. 05 re spectively;of viral encephalitis was （0.84±0.07）×10^3mm^2/s,1. 07±0. 05,0.17±0. 02,0. 43±0. 09 respectively. There were significant differences in the mean ADC values and rADC values （P〈0.01） among the three groups,as well as significant differences in the mean FA values and rFA values （P〈0.01） between low grade cerebral glioma and cerebral infarc tion, so was between viral encephalitis and cerebral infarction （P〈0.01）. Yet there wasn＇t significant difference in the mean FA values and rFA values （P〉0.05） between low grade cerebral glioma and viral encephalitis. Conclusion： The combination of ADC value, rADC value,FA value and rFA value in DTI play an important role in the differential diagnosis of low grade cerebral glioma,cerebral infarction and viral encephalitis.