Influence of boundary conditions on a one-dimensional ultrasound backscattering model of blood.
A simulation model of one-dimensional (1-D) ultrasound (US) propagation in blood was used to study the relation between the backscattering coefficient and hematocrit. In this model, an ultrasonic plane wave was propagated in plasma normal to randomly placed slabs of constant thickness whose acoustical properties are the same as red blood cells, and the corresponding intensity reflection coefficient was calculated. The simulation results were compared to the 1-D Percus-Yevick (P-Y) theory as presented in the literature. Previous investigators have reported a close agreement over a limited range of simulation parameters between their results and the P-Y theory. However, a more careful investigation using a wider range of parameters has revealed major discrepancies. It is shown that these arise from an inappropriate choice of boundary conditions. By averaging the material properties beyond the boundaries of the simulation, as suggested by earlier theoretical work, the results are now in excellent agreement with the P-Y theory over a wide range of simulation parameters.
Lui
E Y
EY
Department of Physiology, University of Toronto, Toronto, Ontario, Canada.
Tavakkoli
J
J
Cobbold
R S
RS
D001769:Blood / Q000000981:diagnostic imaging*; D006400:Hematocrit; D008954:Models, Biological; D014463:Ultrasonography