Abstract:

It is postulated that a major source of scattering in liver is the collagen rich structure of the vessels that comprise the hepatic vasculature system. This collagen rich hepatic vessel structure manifests itself as the branching pattern of the vessels in three dimensions. Past study of these branching patterns in other organs such as the lung has resulted in data and models which have ascribed a fractal description to their organization. A computer based model has been developed of the portal vasculature system of the human liver based on anatomical, physiological data and precepts as well as a fractal methodology. A thin, planar slice of the model is used to represent sites of ultrasound scattering. A simple model is utilized to calculate the ultrasound scattering from the cross sections of the thin-shelled cylinders used to represent the collagen component of the vascular walls. Simulation of the radio frequency scattered waves is carried out along with envelope detection to allow analysis of the first and second order statistics. The resultant statistics are analyzed in light of the parameters utilized to define the model and their variation.