A Method of Estimating the Irregularity of Scattering Medium Using Characteristics of Ultrasonic Speckle.

When examining a random group of scatterers, random granular patterns called speckle appear on echograms obtained by pulse echo ultrasonic diagnostic equipment. In living body organs such as the liver, there is a profound connection between the irregularity of the tissue structure and the severity of the disease. Therefore, if the degree of the irregularity can be estimated through analysis of the echogram, the possibility exists that the properties of the tissues can be diagnosed quantitatively. This paper considers a medium that grouped scatterers as the model of the object end investigates the relationship between the statistics of interference pattern such as the speckle that appears on the ultrasonic echogram and the irregularity of the scattering medium. Also examined is the possibility of estimating the degree of irregularity of the medium from the echogram. From the results of a computer simulation, it is found that if the density of the scatterers is known, the degree of irregularity of the medium can be determined from the value of the signal-to-noise ratio (SNR) statistic of the echogram. In addition, it is learned that by using the SNR as the statistics together with the skewness of the brightness histogram of the image, it is possible to estimate the degree of irregularity and the density of the scatterers. [ABSTRACT FROM AUTHOR]