医学影像学杂志

目的 探讨磁共振弥散加权成像(DWI)最小表观弥散系数(ADC)值在儿童脑胶质瘤分级诊断和肿瘤细胞增殖活性评估中的应用价值。方法 选取脑胶质瘤患儿95例，根据世界卫生组织中枢神经系统肿瘤分类标准分为低级别60例(Ⅰ级45例、Ⅱ级15例)和高级别35例(Ⅲ级21例、Ⅳ级14例)。术前接受MRI检查，在b值为1 000 s/mm²的ADC图像上测量肿瘤实性部分最小ADC值；取手术切除的病变组织标本，行免疫组织化学染色，计算Ki-67指数。结果95例儿童脑胶质瘤DWI最小ADC值为0.490×10^-3～2.039×10^-3 mm²/s，其中低级别儿童脑胶质瘤DWI最小ADC值为0.708×10^-3～2.039×10^-3 mm²/s、高级别儿童脑胶质瘤DWI最小ADC值为0.490×10^-3～0.860×10^-3 mm²/s。低级别儿童脑胶质瘤DWI最小ADC值高于高级别儿童脑胶质瘤DWI最小ADC值(Z=-7.840,P<0.05)。受试者工作特征曲线分析发现，DWI最小ADC值诊断儿童高级别脑胶质瘤的曲线下面积为0.981(95%CI:0.955～0.994,P<0.05)，最佳截断值为0.982×10^-3 mm²/s，此时其诊断儿童高级别脑胶质瘤的灵敏度为94.9%、特异度为100.0%。Spearman相关分析显示，DWI最小ADC值与儿童脑胶质瘤Ki-67指数呈负相关关系(r=-0.652,P<0.05)。结论 磁共振DWI最小ADC值对儿童脑胶质瘤分级诊断具有一定价值，并且还能反映肿瘤细胞增殖活性，对预后评估具有一定辅助作用。

Objective To explore the application value of the minimum apparent diffusion coefficient(ADC) value of magnetic resonance diffusion-weighted imaging(DWI) in the grading diagnosis of glioma in children and the evaluation of tumor cell proliferation activity. Methods A total of 95 children with glioma were selected and divided into the low-grade(45 cases of grade Ⅰ and 15 cases of grade Ⅱ) and the high-grade(21 cases of grade Ⅲ and 14 cases of grade Ⅳ) according to the classification criteria of the central nervous system of the WHO. MRI examination was performed before the operation, and the minimum ADC value of the solid part of the tumor was measured on the ADC image with a b value of 1 000 s/mm². The lesion tissue specimens resected by surgery were selected, pathological sections were prepared, immunohistochemical staining was performed, and the Ki-67 index was calculated. Results The minimum ADC value of 95 cases of pediatric glioma ranged from 0.490×10^-3 to 2.039×10^-3 mm²/s. Among them, the minimum ADC value of low-grade glioma in children was 0.708×10^-3 to 2.039×10^-3 mm²/s, and that of high-grade glioma in children was 0.490×10^-3 to 0.860×10^-3 mm²/s. The minimum ADC value of low-grade glioma in children was higher than that of high-grade glioma in children(Z=-7.840, P < 0.05). Receiver operating characteristic curve analysis revealed that the area under the curve of the minimum ADC value for diagnosing high-grade glioma in children was 0.981(95% CI: 0.955-0.994, P < 0.05), the optimal cut-off value was 0.982×10^-3 mm²/s. At this time, its sensitivity for diagnosing high-grade glioma in children was 94.9% and its specificity was 100.0%. Spearman correlation analysis showed that the minimum ADC value was negatively correlated with the Ki-67 index of glioma in children(r =-0.652, P < 0.05). Conclusion The minimum ADC value in magnetic resonance DWI has certain value in the grading diagnosis of glioma in children, which can also reflect the proliferation activity of tumor cells, playing an auxiliary role in prognosis evaluation.