骨小梁材料特性对超声背散射信号的影响  

Effect of trabecular bone material properties on ultrasonic backscattering signals

作　　者：刘成成[1] 他得安[1] 王威琪[1] 

机构地区：[1]复旦大学电子工程系,上海200433

出　　处：《声学学报》2013年第3期382-388,共7页Acta Acustica

基　　金：上海市重点科技攻关项目(09441900400);国家自然科学基金(11174060);教育部博士点基金(20110071130004);教育部新世纪优秀人才项目(NCET-10-0349)资助项目

摘　　要：基于时域有限差分法(FDTD)建立了松质骨的超声背散射仿真系统,研究了骨小梁材料特性对超声背散射信号的影响。首次得到松质骨中的超声背散射系数(BSC)和积分背散射系数(IBC)随骨小梁材料参数(密度、拉梅常数、黏度系数及声阻抗系数)的变化关系。研究结果表明,IBC随骨小梁密度的增加而增加;BSC和IBC随拉梅常数的增加而增加、随第一黏度系数的增加而近似线性地减小,第二黏度的变化对背散射信号的影响很小;背散射参数随阻抗系数的增加而减小。说明松质骨中的超声背散射特性不仅受骨矿密度(BMD)和骨微结构的影响,还与骨小梁的材料参数密切相关。研究结果有利于理解松质骨中超声的背散射特性,对松质骨骨质状况的评价有一定帮助。An ultrasonic backscattering simulation system was build based on finite difference time domain （FDTD） method, and the effect of trabecular material properties on ultrasonic backscattering in cancellous bones was analyzed. The backscatter coefficient （BSC） and integrated backscatter coefficient （IBC） were numerically investigated with varying trabecular bone material properties, such as density, lam~ coefficients, viscosities, and resistance coefficients, for the first time. The results showed that IBC increases as the trabecular bone density increases. BSC and IBC increase with the lam~ coefficients, but decrease as the first viscosity increases. However, change in the value of second viscosity has no significant impacts on the backscattering. Additionally, it was also found that ultrasonic backscatter parameters decrease with the increase of resistance coefficients. These phenomena illustrated that besides the bone mineral density （BMD） and microarchitecture, trabecular material properties significantly influence the ultrasonic backscattering in cancellous bones. This research is very helpful to understand ultrasonic backscattering in cancellous bones and can be used to assess the cancellous bone status.

关 键 词：超声背散射 散射信号 材料特性 骨小梁 时域有限差分法 黏度系数 骨矿密度 材料参数 

分 类 号：TB39[一般工业技术—材料科学与工程] TN011[电子电信—物理电子学]