COMPUTATIONAL INVESTIGATION ON CSF FLOW ANALYSIS IN THE THIRD VENTRICLE AND AQUEDUCT OF SYLVIUS

In this study, a three dimensional (3D) model of the third ventricle and aqueduct of Sylvius derived from MRI scans was constructed by using Computational Fluid Dynamics (CFD) modeling. Cerebrospinal fluid(CSF) can be modeled as a Newtonian Fluid and its flow through the region of interest (ROI) was visualized using Engineering Fluid Dynamics (EFD).The constructed ROI was regarded as rigid walled and only steady state flow was able to be defined due to the limitations of current software. Different flow rate was simulated at the Foramen of Monro and a small stenosis was modeled at the middle of the aqueduct of Sylvius at a fixed location. This was made corresponding to normal patients with variation of CSF flow rate physiologically and abnormal patients with tumor causing obstruction to or within the aqueduct of Sylvius, respectively. Due to the small dimensions of the ROI geometry, gravity and complex external gravity that acted upon it was considered to be neglected. The results show as the flow rate increase, the pressure drop of CSF in the ROI proportionally increased. For normal CSF flow rate, the presence of stenosis in the aqueduct demonstrates a significant increased pressure drop. ABSTRAK-Dalam kajian ini, model tiga dimensi (3D) untuk ventrikel ketiga dan akueduk Sylvius, yang terhasil daripada pengimejan resonans magnetik telah dikonstruksi menggunakan Permodelan Perkomputeran Dinamik Bendalir (Computational Fluid Dynamics (CFD)). Cecair serebrospinal (Cerebrospinal fluid (CSF)) dimodelkan sebagai bendalir Newtonan dan alirannya melalui kawasan kepentingan (region of interest (ROI)) digambarkan menggunakan Dinamik Bendalir Kejuruteraan (Engineering Fluid Dynamics (EFD)). Kawasan kepentingan yang dikonstruksi dianggap sebagai dinding tegar dan hanya aliran keadaan tunak yang dapat ditakrifkan berdasarkan pengehadan perisian komputer terkini. Kadar aliran yang berbeza disimulasikan di foramen monro dan laluan stenosis yang kecil dimodelkan di tengah-tengah akueduk Sylvius di satu lokasi yang telah ditetapkan. Kaedah ini dijalankan terhadap pesakit normal dengan variasi pada kadar aliran CSF, serta pesakit abnormal yang mempunyai tumor, penyebab sekatan terhadap atau melinkungi akueduk Sylvius. Disebabkan oleh ukuran geometri ROI kecil, tarikan graviti dan graviti luar kompleks yang bertindak ke atasnya diabaikan. Keputusan menunjukkan bahawa apabila kadar aliran meningkat, susutan tekanan CSF di dalam ROI meningkat dengan berkadar. Untuk kadar aliran CSF yang normal, kehadiran stenosis di dalam akueduk membuktikan pertambahan susutan tekanan yang ketara

The effect of stenoses and irregular flow rates in human brain ventricular systems

Apart from irregular flow rate, hydrocephalus can also occur due to flow obstructions of cerebral spinal fluid (CSF) flow from the ventricles to the subarachoid space such as stenosis that builds up at the aqueduct. Since the size of the stenosis can affect the seriousness of hydrocephalus, simulation study can be used as cheaper and more detailed method to provide internal flow pattern inside the aqueduct. In this study, three dimensional models of the third ventricle and the aqueduct of Sylvius derived from MRI scans were constructed and the flow patterns were modeled by using MIMICS and CFD software. The constructed region of interest (ROI) was regarded as rigid wall and steady state flows were assumed. Different flow rates were simulated at the Foramen of Monro and several stenosis of various sizes were modeled at the middle of the aqueduct of Sylvius at a fixed location. These were made corresponding to normal patients with variation of CSF flow rates physiologically, and abnormal patients with tumor causing obstruction to or within the aqueduct of Sylvius, respectively. The results shows that the small difference of stenose sizes (1.2 times) is outweighed the difference of the flow rate (2 times) for contributions to abnormal and hydrocephalus. Unlike normal flow rates, there are flow recirculation appeared in the region of interest (ROI) in hydrocephalus cases. The flow recirculation might cause the pressure increase for abnormal flow rates to stay around at 50% - 60% of range for 10% of increment in stenose size. The analysis of the CSF flow patterns can provide a possible potential risk indicator of stenosis severity to the patients

Mathematical modelling of the hydrodynamic processes in the circulation systems of the nuclear energy plants

The object of investigation: the circulation systems of the nuclear energy plants (NEP). The purpose of the work: creating the methods of the mathematical modeling of the hydrodynamic processes in the NEP circulation systems. The design methods of unstationary hydrodynamic, acoustic and stationary processes in the NEP circulation systems have been developed. The developed numerical methods, algorithms and programs allow to perform the analysis of the hydrodynamic processes in the circulation systems when designing and operating the nuclear energy plantsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Computational investigation on CSF flow analysis in the third ventricle and aqueduct of sylvius

In this study, a three dimensional (3D) model of the third ventricle and aqueduct of Sylvius derived from MRI scans was constructed by using Computational Fluid Dynamics (CFD) modeling. Cerebrospinal fluid(CSF) can be modeled as a Newtonian Fluid and its flow through the region of interest (ROI) was visualized using Engineering Fluid Dynamics (EFD).The constructed ROI was regarded as rigid walled and only steady state flow was able to be defined due to the limitations of current software. Different flow rate was simulated at the Foramen of Monro and a small stenosis was modeled at the middle of the aqueduct of Sylvius at a fixed location. This was made corresponding to normal patients with variation of CSF flow rate physiologically and abnormal patients with tumor causing obstruction to or within the aqueduct of Sylvius, respectively. Due to the small dimensions of the ROI geometry, gravity and complex external gravity that acted upon it was considered to be neglected. The results show as the flow rate increase, the pressure drop of CSF in the ROI proportionally increased. For normal CSF flow rate, the presence of stenosis in the aqueduct demonstrates a significant increased pressure drop