Effect of blood rheology and hematocrit on the estimation of hemodynamic parameters in hypertrophic cardiomyopathy

Motivation: The nonlinear behavior of blood flow depends mainly on the hematocrit percentage (Hct) and can be effectively described using models such as the power-law. Goal(s): This study investigates the influence of blood rheology and Hct percentage on the estimation of wall shear stress, energy loss and oscillatory shear index, in patients with obstructive and non-obstructive hypertrophic cardiomyopathy. Approach: Hemodynamic parameters were quantified using the 4D Flow Matlab Toolbox, an intra- and inter-observer analysis was performed. Non-parametric test were used for statistical analysis. Results: Interobserver variability in hemodynamic parameters and significant differences between constant and variable viscosity, are presented especially in the diastolic phase. Impact: This study shows the impact of incorporating nonlinear blood viscosity models in the estimation of hemodynamic parameters from 4D flow MR imaging in patients with hypertrophic cardiomyopathy. Variable viscosity model produces significant differences in diastolic phase.