The viscoelastic properties of tissues can reflect human physiological and pathological conditions. During and after the high-intensity focused ultrasound (HIFU) treatment, measuring the viscoelasticity of HIFU ablated tissue is important for therapy evaluation. Two-dimensional Fourier transform (2DFT) method has been reported to quantify elasticity and viscosity. However, a deviation is induced by under-sampling in practical application. This work proposes an approach based on the convolution theorem and model fitting to solve the finite spatial data problem. A model using the convolution theorem was constructed, and mean-square error (MSE) was calculated to determine the optimal fitting between the model and experimental data. For validation, HIFU therapeutic experiments were conducted in polyacrylamide-bovine serum (BAS) transparent tissue-mimicking phantoms. This approach was used to quantify the viscoelasticity of HIFU ablation and untreated phantoms. Acoustic-radiation-force (ARF) shear wave was generated by the same HIFU therapeutic transducer, and laser Doppler vibrometer (LDV) was used for the high-resolution measurement of shear wave signals. Results suggest that the shear elasticity and viscosity of untreated phantoms are generally smaller than those of HIFU ablation. Thus, the proposed method may be helpful for HIFU treatment monitoring.

中文翻译：

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用K空间分析结合模型拟合校正方法对剪切波HIFU烧蚀的粘弹性表征

组织的粘弹性能反映人体生理和病理状况。在高强度聚焦超声 (HIFU) 治疗期间和之后，测量 HIFU 消融组织的粘弹性对于治疗评估很重要。据报道，二维傅里叶变换 (2DFT) 方法可以量化弹性和粘度。然而，在实际应用中，欠采样会导致偏差。这项工作提出了一种基于卷积定理和模型拟合的方法来解决有限空间数据问题。构建使用卷积定理的模型，并计算均方误差（MSE）以确定模型与实验数据之间的最佳拟合。为了验证，HIFU 治疗实验在聚丙烯酰胺-牛血清 (BAS) 透明组织模拟幻影中进行。这种方法用于量化 HIFU 消融和未经处理的体模的粘弹性。声辐射力 (ARF) 横波由相同的 HIFU 治疗换能器产生，激光多普勒振动计 (LDV) 用于横波信号的高分辨率测量。结果表明，未经处理的体模的剪切弹性和粘度通常小于 HIFU 消融的剪切弹性和粘度。因此，所提出的方法可能有助于 HIFU 治疗监测。激光多普勒测振仪（LDV）用于剪切波信号的高分辨率测量。结果表明，未经处理的体模的剪切弹性和粘度通常小于 HIFU 消融的剪切弹性和粘度。因此，所提出的方法可能有助于 HIFU 治疗监测。激光多普勒测振仪（LDV）用于剪切波信号的高分辨率测量。结果表明，未经处理的体模的剪切弹性和粘度通常小于 HIFU 消融的剪切弹性和粘度。因此，所提出的方法可能有助于 HIFU 治疗监测。