Estimation of Size of Red Blood Cell Aggregates Using Reference Power Spectra

Estimation of red blood cell aggregation size using power spectrum considering density of red blood cells in focal region

“…By applying the method to in vivo measurements for healthy subjects, the estimated sizes were close to 8 μm corresponding to the diameter of a single RBC under normal blood flow, and they increased by approximately 14 μm under the low shear rate condition by avascularization. 31) In our previous study, 30) there were differences in the shape between the power spectra measured from the microparticles simulating RBCs and the reference scattering power spectra corresponding to the microparticle diameters. In this study, we calculated the reference scattering power spectra by simulating a condition in which only a single scatterer existed at the focus of the ultrasound beam.…”

“…We have studied a noninvasive and quantitative method for measuring the RBC aggregate size using a high-frequency focused ultrasound transducer. [26][27][28][29][30][31] Fukushima et al assumed that aggregated RBCs are single-sphere scatterers and estimated their size from the scattering characteristics by normalizing the power spectrum measured from the vessel lumen by that from the posterior wall of the blood vessel as a reflector. [26][27][28][29] However, the vessel wall could have exhibited a slope to the probe surface and roughness on the surface.…”