基于光声差分衰减频谱的骨质评估仿真研究

光声层析成像术(Photoacoustic Tomography,PAT)在骨组织微结构的量化评估方面具有潜力，但在传统PAT工作模式下，松质骨的固液两相多孔结构导致骨小梁等分布式光吸收成分激发的光声信号混叠，增加了定量分析骨微结构特性的难度和复杂度。针对这一问题，文章将PAT系统改进为偏心激励-差分检测模式，获取差分衰减频谱(Differential Attenuation Spectrum,DAS)；并通过数值仿真计算和验证了松质骨孔隙率与光声差分衰减频谱特征参数的相关性。研究结果表明：提取的光声差分衰减频谱特征参数与骨头孔隙率呈强线性相关，基于光声差分衰减频谱的分析方法可有效实现骨质定量评估和诊断。

Simulation of bone evaluation based on photoacoustic differential attenuation spectrum

otoacoustic tomography (PAT) has the potential for the quantitative assessment of bone microstructure. However, due to the distributed solid-liquid two-phase porous structure of cancellous bone, the PA signals in the traditional PAT system are overlapped, which increases the difficulty and complexity of the quantitative analysis of bone microstructure. To solve this problem, the PAT system is improved to the eccentric excitation-differential detection mode to obtain the differential attenuation spectrum (DAS). The correlation between the porosity of cancellous bone and the characteristic parameters of PADAS is calculated and verified by using numerical simulation. The results show that there is a strong linear correlation between the characteristic parameters of photoacoustic attenuation spectrum and bone porosity, which indicates that the analysis method of the photoacoustic differential attenuation spectrum could effectively realize the quantitative evaluation and diagnosis of bone.