超声表观背散射参数成像定征松质骨结构的可行性研究

Feasibility of characterizing cancellous bone microstructure using ultrasonic apparent backscatter parametric imaging

骨矿密度的降低与骨微结构的退化都会导致骨强度的下降,从而引发骨质疏松。松质骨的超声背散射信号中包含骨微结构信息。本文提出用超声背散射系数(BC)和平均积分背散射系数(AIB)成像来定征松质骨微结构,并对骨样本感兴趣区域(ROI)内的BC和AIB与μ-CT获得的骨结构参数做线性相关分析。研究结果表明,超声背散射参数的平均值与骨小梁厚度(r=0.898)、骨小梁间距(r=–0.916)有较强的相关性。说明利用背散射参数图像来反映松质骨微结构的特征是可行的。

Osteoporosis is characterized by low bone strength, which results from both low bone mass and deteriorated bone microstructure. Ultrasonic backscatter signals might provide information related to bone micro- structure. Backscatter coefficient （BC） and apparent integral backscatter coefficient （AIB） are used to conduct ultrasonic backscatter parametric imaging of bovine tibia bone samples for cancellous bone microstructure characterization. Mean values of BC and AIB in ROIs of bone samples were compared with the bone structure pa- rameters obtained from μ-CT 3D reconstruction. Results indicate that mean backscatter coefficients are highly correlated with trabecular thickness （r=-0.898） and trabecular spacing （r=- -0.916）. Thus, it seems meaningful to provide bone microstructure information by using ultrasonic backscatter parametric imaging.