From the Vagelos College of Physicians and Surgeons (P.B.W.).
Departments of Neurological Surgery (P.B.W., M.B.S., J.N.B.).
AJNR Am J Neuroradiol. 2021 Jul;42(7):1293-1298. doi: 10.3174/ajnr.A7154. Epub 2021 May 13.
Meningioma grade is determined by histologic analysis, with detectable brain invasion resulting in a diagnosis of grade II or III tumor. However, tissue undersampling is a common problem, and invasive parts of the tumor can be missed, resulting in the incorrect assignment of a lower grade. Radiographic biomarkers may be able to improve the diagnosis of grade and identify targets for biopsy. Prior work in patients with gliomas has shown that the resting-state blood oxygen level-dependent fMRI signal within these tumors is not synchronous with normal brain. We hypothesized that blood oxygen level-dependent asynchrony, a functional marker of vascular dysregulation, could predict meningioma grade.
We identified 25 patients with grade I and 11 patients with grade II or III meningiomas. Blood oxygen level-dependent time-series were extracted from the tumor and the radiographically normal control hemisphere and were included as predictors in a multiple linear regression to generate a blood oxygen level-dependent asynchrony map, in which negative values signify synchronous and positive values signify asynchronous activity relative to healthy brain. Masks of blood oxygen level-dependent asynchrony were created for each patient, and the fraction of the mask that extended beyond the contrast-enhancing tumor was computed.
The spatial extent of blood oxygen level-dependent asynchrony was greater in high (grades II and III) than in low (I) grade tumors ( < 0.001) and could discriminate grade with high accuracy (area under the curve = 0.88).
Blood oxygen level-dependent asynchrony radiographically discriminates meningioma grade and may provide targets for biopsy collection to aid in histologic diagnosis.
脑膜瘤的分级是通过组织学分析确定的，有脑侵犯的可诊断为 II 级或 III 级肿瘤。然而，组织取样不足是一个常见的问题，肿瘤的侵袭部位可能会被遗漏，导致低级别的错误诊断。影像学生物标志物可能有助于提高分级诊断，并确定活检的靶点。先前在胶质瘤患者中的研究表明，这些肿瘤内的静息态血氧水平依赖 fMRI 信号与正常大脑不同步。我们假设，血氧水平依赖的不同步，作为血管失调的功能标志物，可以预测脑膜瘤的分级。
我们确定了 25 例 I 级和 11 例 II 级或 III 级脑膜瘤患者。从肿瘤和影像学正常的对侧半球提取血氧水平依赖时间序列，并将其作为预测因子纳入多元线性回归，生成血氧水平依赖的不同步图，负值表示与正常大脑同步，正值表示与正常大脑不同步。为每位患者创建血氧水平依赖不同步的掩模，并计算掩模中超出增强肿瘤的部分的分数。
高（II 级和 III 级）分级肿瘤的血氧水平依赖不同步的空间范围大于低（I 级）分级肿瘤（<0.001），并能准确地区分分级（曲线下面积=0.88）。
血氧水平依赖不同步可在影像学上区分脑膜瘤的分级，可能为活检采集提供目标，以辅助组织学诊断。
