Paper detail

Structural and hemodynamic properties in murine pulmonary arterial networks under hypoxia-induced pulmonary hypertension

Detection and monitoring of patients with pulmonary hypertension, defined as mean blood pressure in the main pulmonary artery above 25 mmHg, requires a combination of imaging and hemodynamic measurements. This study demonstrates how to combine imaging data from microcomputed tomography (micro-CT) images with hemodynamic pressure and flow waveforms from control and hypertensive mice. Specific attention is devoted to developing a tool that processes CT images, generating subject-specific arterial networks in which 1D fluid dynamics modeling is used to predict blood pressure and flow. Each arterial network is modeled as a directed graph representing vessels along the principal pathway to ensure perfusion of all lobes. The 1D model couples these networks with structured tree boundary conditions informed by the image data. Fluid dynamics equations are solved in this network and compared to measurements of pressure in the main pulmonary artery. Analysis of micro-CT images reveals that the branching ratio is the same in the control and hypertensive animals, but that the vessel length to radius ratio is significantly lower in the hypertensive animals. Fluid dynamics predictions show that in addition to changed network geometry, vessel stiffness is higher in the hypertensive animal models than in the control models.