目的 探讨扩散加权成像和MRS 对病毒性脑炎和脑低级星形细胞瘤的鉴 别诊断价值。方法 19例病毒性脑炎和21 例脑低级星形细胞瘤在治疗前或手术前 接受了常规MRI、DWI及MRS检查。病毒性 脑炎经临床生化检查及治疗随访证实， 脑低级星形细胞瘤病例经手术及病理证 实。测量和比较两组病例DWI的表观扩散 系数(ADC)值Cho/Cr,NAA/Cr和Cho/NAA。 结果 病毒性脑炎和低级别胶质瘤的平均 ADC值分别为(1.471±0.032)×10-3mm2 /s 和(1.079±0.201)×10-3mm2 /s(P<0.01)， Cho/Cr值分别为(2.442±0.648) 和(3.992±0.965)(P<0.01),Cho/ NAA值分别为(3.623±1.221)和 (6.585±2.52)(P<0.01)和NAA/Cr值分 别为(2.088±0.484)和(1.292±0.465) (P<0.01)。结论 DWI和MRS对鉴别病毒性 脑炎和脑低级星形细胞瘤具有重要的临床 价值，可作为常规MR检查重要的补充。

Objective To explore the diagnostic value of DWI and MRS for assessment of virus encephalitis versus low-grade glioma. Methods Nineteen patients with virus encephalitis and 20 patients with low-grade glioma were enrolled in this retrospective study. All the study subjects were performed conventional MRI scanning, DWI and MRS sequences. Patients with virus encephalitis were confirmed by clinical biochemical examination and following up, and patients with low-grade glioma were confirmed by histopathology. The values of apparent diffuse coefficient (ADC), Cho/Cr, NAA/Cr and Cho/NAA were measured and compared between virus encephalitis and low-grade glioma group. Results ADC value of virus encephalitis and low-grade glioma group was (1.471±0.032)×10-3mm2 /s and (1.079±0.201)×10-3mm2 /s (P<0.01), respectively. Value of Cho/Cr was (2.442±0.648) and (3.992±0.965)(P<0.01), respectively. Value of Cho/NAA was (3.623±1.221) and (6.585±2.52)(P<0.01), respectively. Value of NAA/ Cr was (2.088±0.484) and (1.292±0.465)(P<0.01). Conclusion There was important clinical value for differential diagnosis of virus encephalitis and low-grade glioma by DWI and MRS, which would play an important role in complementing conventional MRI scan sequences.