Abstract
Blood is supplied to the brain by two internal carotid and two vertebral arteries. These arteries join to form the cerebral arterial circle (also called the Circle of Willis or the CoW). This unique arrangement of human vessels ensures blood supply to the brain in spite of any pathology in the geometry of arteries supplying the brain. Computed Tomography was used in this case for imagining the CoW and the arteries supplying it. The images obtained during the test were employed to develop a numerical model of one particular patient’s vessels geometry. Nowadays, with the use of numerical methods, it is possible to simulate a real flow within the region where no other method can be used, and thus one can analyze an influence of the pathological narrowing onto the cerebral perfusion. Using Computed Tomography, a large series of two-dimensional X-ray images were taken along the patient’s axis during one test. The distance between individual images was 0.6 mm. Vessels – as they are soft tissues – have to be visualized with contrast. On the basis of those images, a three-dimensional path of the single artery was studied and its geometry was generated in CAD software (SolidWorks). Then, a 3D mesh was generated using the CFX Mesh code. The numerical experiment, with use of the Ansys CFX code, was carried out for different velocities within the physiological range. Blood was modelled as a Newtonian fluid.