ADC直方图在高级别胶质瘤与脑单发转移瘤鉴别中的应用价值

Value of apparent diffusion coefficient histogram to differentiating high-grade glioma from solitary brain metastasis

目的探讨表观扩散系数(ADC)直方图鉴别高级别胶质瘤(HGG)与单发脑转移瘤(SBM)的价值。方法回顾性分析病理或临床随访证实的7例HGG与19例SBM(腺癌脑转移瘤11例,鳞癌脑转移瘤8例)的MRI资料,测量瘤体和瘤周水肿区ADC直方图参数,利用受试者工作特征曲线评价ADC直方图参数鉴别HGG与SBM的诊断效能。结果 HGG瘤体ADC第5、25百分位数(ADC_5th、ADC_25th)及瘤周水肿ADC最小值(ADCmin)均明显低于SBM(P<0.05),而瘤体体素计数明显高于SBM(P<0.05)。鳞癌脑转移瘤瘤体ADC_5th、ADC_25th均明显低于腺癌脑转移瘤(P<0.05)。瘤体ADC_5th=926×10^(-6)mm^2/s鉴别诊断HGG与SBM的效能最高。结论 ADC直方图有助于HGG与SBM的鉴别诊断,瘤体ADC_5th鉴别诊断HGG与SBM的效能最高。

Objective To investigate the value of apparent diffusion coefficient(ADC)histogram to differentiating high-grade glioma(HGG)from solitary brain metastasis(SBM).Methods The conventional MRI data of 7 patients with HGG and 19 patients with SBM proved by pathological examination or clinical follow-up were analyzed retrospectively.The parenchyma and peritumoral edema ADC values derived from histogram were measured for each patient.The parameters of HGG and SBM were compared.Receiver operating characteristic(ROC)curve was used to assess the diagnostic performance of ADC histogram in distinguishing the HGG from SBM.Results The ADC_5th and ADC_25th values of the tumorous parenchyma areas and the minimal ADC values of the tumorous peritumoral edema areas were significantly lower in HGG than SBM(P<0.05).The ADC_5th and ADC_25th values of the tumorous parenchyma areas were significantly higher in adenocarcinoma than squamous cell carcinoma(P<0.05).The value of area under ROC curve was the highest when the optimal cutoff value of the ADC_5th values in the parenchyma area was 926×10-6 mm2/s.Conclusions ADC histogram may be helpful to differentiating HGG from SBM,and the diagnostic accuracy of the ADC_5th values in the tumorous parenchyma area is the highest.