From Medical Images to CFD Meshes

. Several image processing operators are combined with various computational geometry techniques, in order to quickly generate discrete surface representations of arteries from medical images. These surface representations are then used to generate finite element meshes suitable for CFD calculations of blood flow in arteries. Keywords. Mesh Generation, Hemodynamics, Medical Images. 1 Introduction The proper flow of blood through the human body is directly related to wellbeing and health. Blood delivers oxygen and nutrients to muscles and tissues, and removes residues and other harmful substances from the cells. The obstruction of blood flow leads to several common diseases [1]: Atherosclerosis, a disease of large and medium size arteries [2, 3, 4], is the main cause of death in the U.S. and most of the world [5]. Clinical observations have shown that atherosclerosis has a pattern which is of local nature and that sites of branching, high curvature and bifurcation are associated ..

Blood-flow characteristics in a terminal basilar tip aneurysm prior to its fatal rupture

BACKGROUND AND PURPOSE: The development and validation of methods to stratify the risk of rupture of cerebral aneurysms is highly desired since current treatment risks can exceed the natural risk of rupture. Because unruptured aneurysms are typically treated before they rupture, it is very difficult to connect the proposed risk indices to the rupture of an individual aneurysm. The purpose of this case study was to analyze the hemodynamic environment of a saccular aneurysm of the terminal morphology sub-type that was imaged just prior to its rupture and to test whether the hemodynamic characteristics would designate this particular aneurysm as at high risk. METHODS: A patient-specific computational fluid dynamics model was constructed from 3D rotational angiography images acquired just hours before the aneurysm ruptured. A pulsatile flow calculation was performed and hemodynamic characteristics previously connected to rupture were analyzed. RESULTS: It was found that the aneurysm had a concentrated inflow stream, small impingement region, complex intra-aneurysmal flow structure, asymmetric flow split from the parent vessel to the aneurysm and daughter branches, and high levels of aneurysmal wall shear stress near the impaction zone. CONCLUSIONS: The hemodynamics characteristics observed in this aneurysm right before its rupture are consistent with previous studies correlating aneurysm rupture and hemodynamic patterns in saccular and terminal aneurysms. This study supports the notion that hemodynamic information may be used to help stratify the rupture risk of cerebral aneurysms