Ultrasound backscattering by three-dimensional distributions of aggregated red blood cells: A Monte Carlo study

We present a Monte Carlo study on ultrasound backscattering by three-dimensional distributions of aggregated red blood cells (RBCs). In this study, particles were allowed to interact attractively with neighbors to form aggregates. The interaction potential energy profile between a pair of particles was mimicked by the Morse potential. The strength of pair interaction energy was controlled by fixing depth and width of the potential. Some three-dimensional configurations of cells representing realizations of the system were simulated by employing the Metropolis algorithm. The frequency dependent backscattering coefficient (BSC) was determined at three hematocrits, H = 20%, 30% and 40% and at different aggregation levels. It was noticed that BSC increased and spectral slope (SS) decreased as the aggregating potential was raised and the effect was more pronounced at higher hematocrits, particularly at 40%. In conclusion, this model can generate three-dimensional configurations of aggregated cells and can capture the role of RBC aggregation on BSC and SS.