National Neuroimaging Facility, National Brain Research Center, Manesar, Haryana, 122052, India.
Institute of Psychiatry, Psychology & Neuroscience, King's College, London, UK.
J Neurooncol. 2019 Aug;144(1):165-177. doi: 10.1007/s11060-019-03217-9. Epub 2019 Jul 1.
Corpus callosum (CC) is a main channel histologically for glioma spreading, downgrading the prognosis, the infiltration occurring through cellular reaction-diffusion process. Preliminary clinical trial indicates that CC's surgical interruption appreciably enhances clinical outcome. We aim to find how high-grade glioma phenomenology is reflected in CC parameters, including various 3D diffusion eigenvalues differentially, whereby this information may be utilized for planning radiotherapy and surgical intervention.
Using 3 Tesla MRI diffusion-tensor imaging of glioma patients and matched controls, we formulated the callosal volume, fibre count, and 3D directional diffusivity eigenvalues (λ-λ-λ), utilizing FDT/FMRIB-based analysis.
In glioma, the callosal volume, fibre count and normalized volume decreases (p < 0.001), while axial diffusivity λ and radial diffusivity component λ significantly increase (p = 0.03, p = 0.04). Though not expected, the other radial diffusivity component λ remains unchanged (p = 0.11). Increase of λ and λ is due to gliomatous migration across the two directions (eigenvectors of λ, λ), which correlate respectively with medio-lateral commissural fibres and dorso-ventral perforating fibres in CC. These are corroborated by collateral radiological findings and immunohistological staining of those two fibre-systems in cat and human.
In glioma, the two diffusivities (λ, λ), enhance due to fluidic edema permeation through CC's bi-axial lamina-type structural scaffold, formed by mediolateral commissural fibres and dorsoventral perforating cingulo-septal fibres. On other hand, the two radial diffusivities (λ, λ) are physiologically different and can be distinguished as lamellar diffusivity and focal diffusivity respectively. Lamellar diffusivity λ needs to be considered for MRI-assisted surgical intervention and radiotherapy planning in glioma.
胼胝体（CC）是组织学上胶质瘤扩散的主要通道，降低了预后，浸润通过细胞反应-扩散过程发生。初步临床试验表明，CC 的手术中断显著提高了临床结果。我们旨在寻找高级别胶质瘤表型如何反映在 CC 参数中，包括各种 3D 扩散特征值的差异，从而可以将这些信息用于规划放疗和手术干预。
我们使用胶质瘤患者和匹配对照的 3T MRI 扩散张量成像，利用基于 FDT/FMRIB 的分析方法构建了 CC 的体积、纤维计数和 3D 方向扩散特征值（λ-λ-λ）。
在胶质瘤中，CC 的体积、纤维计数和归一化体积减少（p < 0.001），而轴突扩散率 λ 和径向扩散率 λ 显著增加（p = 0.03，p = 0.04）。尽管出乎意料，但其他径向扩散率 λ 保持不变（p = 0.11）。λ 和 λ 的增加是由于胶质瘤在两个方向上迁移（λ、λ 的特征向量）所致，它们分别与 CC 中的中侧连合纤维和背侧-腹侧穿透纤维相关。这些与 cat 和人 CC 中这两种纤维系统的间接放射学发现和免疫组织化学染色相吻合。
在胶质瘤中，由于流体性水肿通过 CC 的双轴板状结构支架渗透，两种扩散率（λ、λ）增强，该支架由中侧连合纤维和背侧-腹侧穿透扣带-隔束纤维组成。另一方面，两种径向扩散率（λ、λ）在生理上是不同的，可以分别区分为板状扩散率和局灶性扩散率。板状扩散率 λ 需要考虑用于 MRI 辅助手术干预和胶质瘤放疗计划。
