Optimization of focal-region width to estimate the size of red blood cell aggregates using ultrasound backscatter characteristics

Abstract

We previously proposed a noninvasive and quantitative method for estimating the aggregate size of red blood cells (RBCs) based on ultrasound backscatter characteristics. In this study, we improved the estimation accuracy by appropriately setting the focal-region width of the ultrasound beam used to calculate the reference scattering power spectra. Phantom experiments using blood-mimicking particles demonstrated that a wider focal region yielded an estimate closer to the true value and reduced the root-mean-square error (RMSE) of the spectral fitting compared with the conventional width. This result indicates that an appropriate focal-region size enhances the accuracy of RBC aggregate size estimation.