title: Forward problem study of an effective medium model for ultrasound blood characterization.
abstract: The structure factor model (SFM) is a scattering model developed to simulate the backscattering coefficient (BSC) of aggregated red blood cells (RBCs). However, the SFM can hardly be implemented to estimate the structural aggregate parameters in the framework of an inverse problem formulation. A scattering model called the effective medium theory combined with the SFM (EMTSFM) is thus proposed to approximate the SFM. The EMTSFM assumes that aggregates of RBCs can be treated as individual homogeneous scatterers, which have effective properties determined by the acoustical characteristics and concentration of RBCs within aggregates. The EMTSFM parameterizes the BSC by three indices: the aggregate radius, the concentration of RBCs with- in aggregates (the aggregate compactness), and the systemic hematocrit. The goodness of fit of the EMTSFM approximation in comparison with the SFM was then examined. Based on a 2-D study, the EMTSFM was found to approximate the SFM with relative errors less than 30% for a product of the wavenumber times the mean aggregate radius krΛκ <; 1.32. The main contribution of this work is the parameterization of the BSC with the RBC aggregate compactness, which is of relevance in clinical hemorheology because it reflects the binding energy between RBCs.
authors: Laboratoire de Mecanique et d’Acoustique, Centre National de la Recherche Scientifique UPR 7051, Marseille, France. franceschini@lma.cnrs-mrs.fr
authors: Emilie
authors: E
authors: Franceschini
authors: Bloen
authors: B
authors: Metzger
authors: Guy
authors: G
authors: Cloutier
mesh_terms: D000818:Animals; D001769:Blood / Q000000981:diagnostic imaging*; D003198:Computer Simulation; D004903:Erythrocyte Aggregation / Q000502:physiology*; D004912:Erythrocytes / Q000000981:diagnostic imaging* / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008955:Models, Cardiovascular; D014463:Ultrasonography