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提出基于超声射频信号的数字减影损伤区域成像方法,并根据成像结果采用对数谱差衰减系数估计法对高强度聚焦超声引起的软组织损伤程度进行评价。通过离体牛肉和牛肝组织实验,获得了绝对差值法、绝对差值求和法以及平方差值求和法的数字减影结果,分析了这些算法的性能以及阈值和窗宽的选取对算法的影响。在此基础上,比较了用于损伤程度评价的三种声衰减估计参量,证实了采用超声换能器带宽范围内的平均衰减系数的改变△(?)进行组织损伤程度评价的有效性。
Based on the results of imaging, the method of logarithmic spectral difference attenuation coefficient estimation was used to evaluate the degree of soft tissue damage caused by high intensity focused ultrasound. Through the experiments of isolated beef and bovine liver tissue, the digital subtraction results of absolute difference method, sum of absolute difference method and summing method of square difference method were obtained. The performance of these algorithms and the choice of threshold and window width were analyzed. Impact. On this basis, the three acoustic attenuation estimation parameters used for the evaluation of the damage degree are compared, and the validity of the evaluation of the tissue damage degree is confirmed by using the change Δ (?) Of the average attenuation coefficient within the bandwidth of the ultrasonic transducer.