title: Morphometry-based impedance boundary conditions for patient-specific modeling of blood flow in pulmonary arteries.
abstract: Patient-specific computational models could aid in planning interventions to relieve pulmonary arterial stenoses common in many forms of congenital heart disease. We describe a new approach to simulate blood flow in subject-specific models of the pulmonary arteries that consists of a numerical model of the proximal pulmonary arteries created from three-dimensional medical imaging data with terminal impedance boundary conditions derived from linear wave propagation theory applied to morphometric models of distal vessels. A tuning method, employing numerical solution methods for nonlinear systems of equations, was developed to modify the distal vasculature to match measured pressure and flow distribution data. One-dimensional blood flow equations were solved with a finite element method in image-based pulmonary arterial models using prescribed inlet flow and morphometry-based impedance at the outlets. Application of these methods in a pilot study of the effect of removal of unilateral pulmonary arterial stenosis induced in a pig showed good agreement with experimental measurements for flow redistribution and main pulmonary arterial pressure. Next, these methods were applied to a patient with repaired tetralogy of Fallot and predicted insignificant hemodynamic improvement with relief of the stenosis. This method of coupling image-based and morphometry-based models could enable increased fidelity in pulmonary hemodynamic simulation.
authors.affiliation: Department of Mechanical Engineering, Stanford University, Clark Center E350B, 318 Campus Drive, Stanford, CA 94305-5431, USA.
authors.forename: Ryan L
authors.initials: RL
authors.lastname: Spilker
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Feinstein
authors.forename: David W
authors.initials: DW
authors.lastname: Parker
authors.forename: V Mohan
authors.initials: VM
authors.lastname: Reddy
authors.forename: Charles A
authors.initials: CA
authors.lastname: Taylor
mesh_terms: D001783:Blood Flow Velocity; D003251:Constriction, Pathologic / Q000503:physiopathology; D020342:Finite Element Analysis; D006330:Heart Defects, Congenital / Q000503:physiopathology*; D006801:Humans; D008955:Models, Cardiovascular; D011651:Pulmonary Artery / Q000503:physiopathology*; D014655:Vascular Resistance