Ultrasonic backscattering in tissue: characterization through Nakagami-generalized inverse Gaussian distribution

Ultrasonic tissue characterization through composite probability distributions such as Nakagami-lognormal, Nakagami-gamma, Nakagami-inverse Gaussian has been found to be useful. Such a probabilistic description also depicts heavy tails which arise from multiple scattering in tissue besides local and global variations in scattering cross-sections. A new composite probability distribution, viz. Nakagami-generalized inverse Gaussian distribution (NGIGD) with four parameters is proposed which under different limiting conditions results in approximating the known distributions. A salient aspect of the new distribution is that the probability density function (pdf) of NGIGD variate is available in closed form and is analytically tractable.