Chen X, Phillips D, Schwarz K Q, Mottley J G, Parker K J
Center for Biomed. Ultrasound, Rochester Univ., NY.
IEEE Trans Ultrason Ferroelectr Freq Control. 1997;44(2):515-25. doi: 10.1109/58.585136.
A new formulation for obtaining the absolute backscatter coefficient from pulse-echo measurements is presented. Using this formulation, performing the diffraction correction and system calibration is straightforward. The diffraction correction function for the measurement of backscatter coefficient and the acoustic coupling function for a pulse-echo system are defined. Details of these functions for two very useful cases are presented: a flat disk transducer and a spherically focused transducer. Approximations of these functions are also provided. For a flat disk transducer, the final formulation appears as a modification to the established Sigelmann-Reid formulation. For a focused transducer, the final correction is a weak function of frequency when the scattering volume is near the focal area, rather than the frequency squared dependence proposed by earlier investigators.
提出了一种从脉冲回波测量中获取绝对后向散射系数的新公式。使用该公式，进行衍射校正和系统校准非常简单。定义了用于测量后向散射系数的衍射校正函数和脉冲回波系统的声耦合函数。给出了两种非常有用情况（平面圆盘换能器和球面聚焦换能器）下这些函数的详细信息。还提供了这些函数的近似值。对于平面圆盘换能器，最终公式表现为对已有的西格曼 - 里德公式的修正。对于聚焦换能器，当散射体积靠近焦区时，最终校正对频率的依赖较弱，而不是早期研究者提出的与频率平方相关。
