Clarification of relation between acoustic characteristic and ultrasonic image of biological tissue

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In the clinical diagnosis using ultrasonic diagnostic equipment, it is difficult to understand the tissue structure by using only two dimensional plane information of ultrasonic B-mode image. In this research, we tried to understanding the relationship between the tissue change that caused by some disease such as fibrosis and the characteristics change (of echo signal for ultrasonic images).The three dimensional echo filter was disigned to improve the accuracy when data is collected with ultrasonic diagnostic equipment. The resolution of the ultrasonic beam which was irradiated to human body is differs respectively in depth, the azimuth, and the direction of the elevation. Then, the measurement accuracy for every has been improved by deciding the parameter of the filter based on resolution in the direction of three dimensions.Moreover, we proposed signal analyzing methods for quantitative diagnosis. Our methods paid attention to the relation between the scatter density and the characteristics of echo signal in the living human body. Quantifying the feature of a different element in an inhomogeneous medium (diseased tissue) became possible by combining some analytical methods.In addition, the system to measure the acoustic characteristic of the biological tissue high-speed and in a high density was restructured. As a result of measurement of eight liver specimens, the measurement speed and the range that can be measured quadrupled compared with the previous system. As a result, the error margin because of the change in the measurement environment decreased, and a highly accurate measurement became possible.