Probability density of myocardial ultrasonic backscatter

The Rayleigh and Rice-Nakagami probability density functions (PDFs) are generally accepted models for the RF envelope of ultrasonic backscatter from tissue. However, theoretical computations and experimental results from a tissue equivalent phantom and in vivo canine myocardium suggest that these two PDFs are overly simplistic expressions of a more complex scattering process occurring in tissue. This process is modeled more precisely by the Nakagami-M PDF which is a compact expression for the most general form of the two-dimensional random walk satisfying the central limit theorem. An analysis of ultrasonic backscatter from a Rayleigh phantom is presented with initial results from normal myocardium to substantiate this finding and address its implications for a deeper understanding of the phenomenon of ultrasonic scattering in tissue