Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Asian Pac J Cancer Prev. 2021 Apr 1;22(4):1129-1136. doi: 10.31557/APJCP.2021.22.4.1129.
To evaluate the role of diffusion MRI in differentiating pediatric posterior fossa tumors and determine the cut-off values of ADC ratio to distinguish medulloblastoma from other common tumors.
We retrospectively reviewed MRI of 90 patients (7.5-year median age) with pathologically proven posterior fossa tumors (24 medulloblastoma, 7 ependymoma, 4 anaplastic ependymoma, 13 pilocytic astrocytoma, 30 diffuse intrinsic pontine glioma (DIPG), 4 ATRT, 3 diffuse astrocytoma, 2 high grade astrocytoma, 2 glioblastoma, and 1 low grade glioma). The conventional MRI characteristics were evaluated. Two readers reviewed DWI visual scale and measured ADC values by consensus. ADC measurement was performed at the solid component of tumors. ADC ratio between the tumors to cerebellar white matter were calculated.
The ADC ratio of medulloblastoma was significantly lower than ependymoma, pilocytic astrocytoma and DIPG. The ADC cut-off ratio of ≤ 1.115 allowed discrimination medulloblastoma from other posterior fossa tumors with sensitivity, specificity, PPV and NPV of 95.8%, 81%, 67.6% and 97.9%, respectively. ADC ratio cut-off level to differentiate medulloblastoma from ependymoma was ≤ 0.995 with area under the curve (AUC)= 0.8693. ADC ratio cut-off level for differentiate medulloblastoma from pilocytic astrocytoma at ≤ 1.17 with AUC = 0.9936. ADC cut-off level for differentiate medulloblastoma from DIPG at ≤ 1.195 with AUC = 0.9681. The ADC ratio was correlated with WHO grading by the lower ADC ratio associated with the higher grade. Furthermore, High DWI visual scale was associated with high grade tumor.
Diffusion MRI has a significant role in diagnosis of pediatric posterior fossa tumors. ADC ratio can be used to distinguish medulloblastoma from other posterior fossa tumor with good level of diagnostic performance.
评估扩散 MRI 在鉴别小儿后颅窝肿瘤中的作用，并确定 ADC 比值的截断值以区分髓母细胞瘤与其他常见肿瘤。
我们回顾性分析了 90 例经病理证实的后颅窝肿瘤患者（7.5 岁中位年龄）的 MRI 资料（24 例髓母细胞瘤、7 例室管膜瘤、4 例间变性室管膜瘤、13 例毛细胞型星形细胞瘤、30 例弥漫性内在脑桥胶质瘤（DIPG）、4 例高级别弥漫性中线胶质瘤（ATRT）、3 例弥漫性星形细胞瘤、2 例高级别星形细胞瘤、2 例胶质母细胞瘤和 1 例低级别胶质瘤）。评估了常规 MRI 特征。两位读者通过共识评估了 DWI 视觉评分并测量了 ADC 值。ADC 值的测量在肿瘤的实体部分进行。计算肿瘤与小脑白质之间的 ADC 比值。
髓母细胞瘤的 ADC 比值明显低于室管膜瘤、毛细胞型星形细胞瘤和 DIPG。ADC 比值≤1.115 可区分髓母细胞瘤与其他后颅窝肿瘤，其敏感性、特异性、PPV 和 NPV 分别为 95.8%、81%、67.6%和 97.9%。ADC 比值≤0.995 可用于区分髓母细胞瘤和室管膜瘤，曲线下面积（AUC）为 0.8693。ADC 比值≤1.17 可用于区分髓母细胞瘤和毛细胞型星形细胞瘤，AUC 为 0.9936。ADC 比值≤1.195 可用于区分髓母细胞瘤和 DIPG，AUC 为 0.9681。ADC 比值与 WHO 分级相关，较低的 ADC 比值与较高的分级相关。此外，高 DWI 视觉评分与高级别肿瘤相关。
扩散 MRI 在小儿后颅窝肿瘤的诊断中具有重要作用。ADC 比值可用于区分髓母细胞瘤与其他后颅窝肿瘤，具有良好的诊断性能。
