The effect of packing order on ultrasound backscatter from cells at different volume fractions
Baddour RE, Kolios MC
Recently, new high frequency ultrasound devices have emerged with better system signal-to-noise ratio characteristics, which make it possible to measure ultrasound scattering in tissues so that small variations in scatterer volume fraction, which can result from changes in tissue microstructure due to cancer therapies, may have a significant impact on the backscattered signal. Previous studies have shown that the backscattered ultrasound power from suspensions of scatterers is related to the fraction of the total volume occupied by the scatterers. Although this volume fraction effect has been well studied for certain biological scatterers, in particular red blood cells (Shung et al., 1984; Mo et al., 1994), the sensitivity of these responses to packing order, assuming no aggregation, have not been investigated. In this study, a three-dimensional computer model was used to study the effect of position randomness on the ultrasound backscatter from cell suspensions at several volume fractions.