DWI对病毒性脑炎、脑梗死和脑低级星形细胞瘤的鉴别诊断价值

The Value of DWI in the Differential Diagnosis Between Viral Encephalitis, Cerebral Infarction and Low grade Astrocytomas

目的探讨扩散加权成像(DWI)对病毒性脑炎、脑梗死和脑低级星形细胞瘤的鉴别诊断价值。资料与方法26例病毒性脑炎和25例脑梗死病例在急性或亚急性阶段、19例脑低级星形细胞瘤在治疗前或手术前接受了常规MRI、DWI检查。病毒性脑炎和脑梗死病例均经临床治疗及随访证实,脑低级星形细胞瘤病例均经手术病理证实。测量并计算3组病例DWI的表观扩散系数(ADC)值和相对表观扩散系数(rADC)值,采用SAS8.2统计分析软件对各组病例ADC值之间以及rADC值之间进行统计学检验。结果病毒性脑炎平均最小ADC值和rADC值分别为(0.93±0.29)×10-3mm2/s和1.07±0.31,脑梗死平均最小ADC值和rADC值分别为(0.49±0.14)×10-3mm2/s和0.65±0.19,脑低级星形细胞瘤平均最小ADC值和rADC值分别为(1.35±0.25)×10-3mm2/s和1.60±0.34。病毒性脑炎、脑梗死和脑低级星形细胞瘤的平均最小ADC值(F=62.33,P<0.01)之间以及rADC值(F=53.04,P<0.01)之间的差异有统计学意义,脑低级星形细胞瘤的ADC值和rADC值最高,脑梗死的ADC值和rADC值最低。结论DWI的ADC值和rADC值能较好地鉴别病毒性脑炎、脑梗死和脑低级星形细胞瘤。

Objective To explore the value of diffusion weighted imaging （DWI） in the differential diagnosis between viral encephalitis, cerebral infarctions and low grade astrocytomas, Materials and Methods The conventional MR imaging and DWI were performed in 70 cases （26 cases with acute or subacute viral encephalitis, 25 cases with acute or subacute cerebral infarctions, and 19 cases with low grade astrocytomas） before treatments or operations. The diagnosis was made clinically in cases with viral encephalitis or cerebral infarctions and were confirmed surgically and pathologically in cases with low grade astrocytomas. The apparent diffusion coefficient （ADC） values and relative apparent diffusion coefficient （rADC） values of the three group were calculated and analyzed, and then statistical analyses were performed with one way ANOVA by using the software of SAS 8.2. Resuits The mean minimum ADC values and rADC values were （0.93 ± 0.29） ×10^-3 mm^2/s and 1.07 ± 0.31 respectively in the viral encephalitis; （0.49 ± 0.14） × 10^-3 mm^2/s and 0.65 ±0.19 respectively in the cerebral infarctions; and （1.35 ± 0.25） ×10^-3 mm^2/s and 1.60 ± 0.34 respectively in the low grade astrocytomas. There was significant difference among the mean minimum ADC values （ F = 62.33, P 〈 0.01 ） or rADC values （ F = 53.04, P 〈 0.01 ） of the three groups. The ADC values and rADC values of the low grade astrocytomas were the highest and those of the cerebral infarctions were the lowest. Conclusion The ADC value and rADC value of DWI play important roles in the differential diagnosis between viral encephalitis, cerebral infarctions and low grade astrocytomas.