Vardakis John C, Chou Dean, Tully Brett J, Hung Chang C, Lee Tsong H, Tsui Po-Hsiang, Ventikos Yiannis
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK.
Institute of Biomedical Engineering & Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK.
Med Eng Phys. 2016 Jan;38(1):48-57. doi: 10.1016/j.medengphy.2015.09.006. Epub 2015 Dec 31.
Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference - Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model).
脑水肿可被归类为由细胞间液体积膨胀产生的明显肿胀。脑积水可以简要描述为脑内脑脊液（CSF）的异常积聚，最终导致实质组织特定部位的水肿。以脑积水为试验平台，人们能够解释水肿形成与脑液产生、运输和引流之间相互作用所涉及的必要机制。关于综合脑动力学和传输现象的当前知识状态表明，多孔弹性理论可能提供一个合适的框架来更好地理解各种疾病。在这项工作中，多网络多孔弹性理论（MPET）被用于开发一种新颖的时空模型，用于描述脑环境不同尺度内的流体调节和组织位移。该模型通过两种形式应用，一种是一维有限差分-计算流体动力学（CFD）耦合框架，另一种是二维有限元方法（FEM）公式。这些用于研究内镜下第四脑室造瘘术在减轻因第四脑室出口梗阻导致的水肿形成中的作用（一维耦合模型），此外还用于观察有限元模板捕捉与水肿形成相关的重要特征的能力，例如在脑室周围区域（二维模型）。
