高、中b值DWI瘤周水肿区ADC值对鉴别恶性胶质瘤和单发转移瘤的价值

Apparent diffusion coefficient value of high and moderate b value DWI in peritumoral edema regions for differentiating malignant glioma and solitary brain metastasis

目的:探讨高、中b值扩散加权成像(DWI)瘤周水肿区表观扩散系数(ADC)值对恶性胶质瘤与单发转移瘤的鉴别诊断价值。方法:回顾性分析经手术病理的18例恶性胶质瘤和15例单发脑转移瘤患者的MRI资料,均行常规MRI检查和2种b的DWI检查(b=1 000 s/mm^2、3 000 s/mm^2),测量瘤体及瘤周表观扩散系数(ADC)值,对不同b值瘤周水肿区的ADC值绘制ROC曲线,寻找最佳诊断阈值。结果:恶性胶质瘤与单发脑转移瘤瘤周水肿区的ADC 1 000、ADC 3 000分别为:(1.123±0.148)×10^(-3)mm^2/s和(1.538±0.184)×10^(-3)mm^2/s、(1.032±0.097)×10^(-3)mm^2/s和(1.242±0.102)×10-3mm^2/s,差异均有统计学意义(P<0.05)。当ADC 1 000取1.30×10^(-3)mm^2/s作为鉴别恶性胶质瘤和单发转移瘤的诊断阈值时,其诊断价值较高,敏感度和特异度分别为93.3%、72.2%。结论:瘤周水肿区ADC值有助于恶性别胶质瘤与转移瘤的鉴别,b值取1 000 s/mm2时瘤周水肿ADC值对于二者鉴别最佳。

Objective：To investigate the value of diffusion-weighted imaging（ DWI） with moderate and high b value by analyzing the apparent diffusion coefficient obtained from peritumoral edema in diagnosing malignant glioma and solitary brain metastasis.Methods：18 high grade gliomas and 15 solitary metastasis with pathologicallyproved were studied retrospectively.All patients received conventional MRI and DWI examination with 2 different b values（ 1 000 s/mm2,3 000 s/mm2）.ADC values of different b value within the tumor and peritumoral area were measured.Results：The ADC 1 000 and ADC 3 000 in the peritumoral regions of high grade gliomas was significantly lower than that of solitary metastasis（ 1.123±0.148）×10-3mm2/s and（ 1.538±0.184）×10-3mm2/s,（ 1.032±0.097）×10-3mm2/s and（ 1.242±0.102）×10-3mm2/s respectively with statistically significant（P〈0.05）.When ADC 1 000 took 1.30×10-3mm2/s as the diagnostic threshold value for high grade gliomas and solitary metastasis,the sensitivity and specificity were 93.3% and 72.2% respectively.Conclusion：The ADC values in peritumoral edema is helpful and the b-value of 1 000 s/mm2 is optimal in differentiating high-grade glioma and solitary metastasis.