CSF is a clear liquid that its mechanical properties are to a large extent similar to water properties. Regarding the lack of a numerical index for diagnosis of diseases resulting from increased CSF pressure such as hydrocephalus, evaluation of hydrodynamic conditions of CSF in cerebral ventricular system is of great importance. At first, brain tissue is assumed to be a rigid body and CSF flow around the rigid brain was modeled. At the next level, 3D fluid-structure interaction modelling was utilized for simulation normal case and non-communicating hydrocephalus patient brain to study details of CSF flow around the elastic brain tissue. The results confirmed an appropriate correlation between increase in the range of jugular vein pressure and CSF velocity in the brain ventricles and canals. It means that, when the blood pressure range changes to critical situation, CSF velocity increase, especially in aqueduct of sylvius. Assumption of brain tissue as a rigid body can not satisfy the experimental results from MRI. There is different numbers for young’s Module that reports by papers [41, 43], and in simulation of elastic brain, five different elasticity coefficients used for brain tissue. The best prediction of CSF flow in aqueduct of sylvius achieve by elasticity of 200kPa for brain tissue. The maximum velocity of flow in aqueduct of sylvius is about 4cm/s that conform the MRI results. Keywords: Cerebrospinal Fluid, Brain tissue, Subarachnoid space, Communicating Hydrocephalus, Fluid and structure interaction, Rigid, Elastic.
