Rician inverse Gaussian model of scattering in ultrasound contrast media

A statistical analysis of 1
^st
and 2
^nd
harmonic echoes backscattered from contrast media using Rician inverse Gaussian (RiIG) envelope model is described. Knowledge of statistics of the scattered signal may contribute to perfusion analysis. A range of ultrasound contrast agent (UCA) concentrations is examined. The RiIG distribution was fitted to image histograms, using Matlab Global optimization toolbox. Influence of simulated attenuation was also tested. Analysis of resulting RiIG distribution parameters shows that while its parameters α and β do not follow any properties of the changing concentration, parameter δ shows logarithmic dependence on concentration in range of 3.125 - 50 mg/l. Taking into account simulated attenuation, we observed that the range and shape of the dependency remain stable, although the actual range of parameter δ decreases with increasing attenuation. This analysis contributes to our previous results, where the Nakagami distribution showed similar dependence of the shape parameter on UCA concentration in a smaller, partially overlapping, concentration range.