基于相位迁移的超声平面波多层皮质骨成像  

Phase shift migration based plane-wave imaging of cortical bone

作　　者：张芸芸 李义方 石勤振 许乐修 戴菲 邢文宇 他得安 Zhang Yun-Yun;Li Yi-Fang;Shi Qin-Zhen;Xu Le-Xiu;Dai Fei;Xing Wen-Yu;Ta De-An(Center for Biomedical Engineering,School of Information Science and Technology,Fudan University,Shanghai 200438,China;Academy for Engineering and Technology,Fudan University,Shanghai 200438,China)

机构地区：[1]复旦大学信息科学与工程学院,生物医学工程中心,上海200438 [2]复旦大学工程与应用技术研究院,上海200438

出　　处：《物理学报》2023年第15期127-136,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11827808,12034005,12274094);中国博士后科学基金(批准号:2022M720814)资助的课题.

摘　　要：皮质骨是一种高衰减、各向异性、高声阻抗的多层生物组织.其结构和材料特性导致高频超声难以穿透其多层结构,从而获取高质量图像.传统超声动态聚焦成像以均匀声速假设为前提,且受制于发射能量和帧率,难以实现多层结构的准确、快速重建,限制其临床应用的推广.针对以上问题,本文提出一种基于相位迁移的平面波骨成像方法(PSM-PW-VI),实现了皮质骨多层结构的精确和快速重建.首先利用超声走时反演估计成像区域的声速分布;然后应用频域相位迁移平面波相干复合方法并行重建上下两个相控阵探头对应的超声图像;最后将两幅图像融合得到完整的皮质骨超声图像.仿真、仿体、离体实验共同验证了该方法的有效性.无论是三层还是五层模型的皮质骨,其厚度的平均误差均小于0.2 mm,相对误差小于7%.此外,与基于相位迁移合成孔径(PSM-SA)方法相比,在相同的工作频率下,该方法具有更深的成像深度和更快的成像速度.实验结果表明,该方法是一种准确高效的皮质骨超声成像方法,对超声骨成像技术的发展和临床研究具有一定的借鉴意义.Cortical bone,a highly attenuated,anisotropic,and multilayered biological medium with high acoustic impedance,presents significant challenges for high-frequency ultrasound to penetrate its complex structure and acquire high-quality images.The traditional method of using uniform sound velocity in ultrasonic dynamic focusing imaging is limited by emission energy and frame rate,which hinders the accurate and rapid reconstruction of multi-layer structures and clinical applications.In order to meet these challenges,this study proposes a novel method,called the phase shift migration-based plane-wave bone imaging via velocity inversion(PSM-PW-VI),that can accurately and quickly image the multi-layer structure of cortical bone.In the PSMPW-VI method,two identical linear array probes are arranged in parallel on both sides of the cortical bone for data acquisition.First,the ultrasound velocity distribution in the imaging region is obtained by using ultrasound travel time inversion.Next,two images corresponding to the upper probe and lower probe are acquired in parallel in the frequency domain by employing a phase shift migration-based coherent plane-wave compounding method.Finally,the two images are merged to generate a complete ultrasound image of the cortical bone.Wave propagation in cortical bone is simulated by using the open source toolbox k-wave in MATLAB.Ex-vivo experiments are conducted on 2.5-mm-thick sawbones phantom and 2.45-mm-thick bovine bone plates to evaluate the feasibility of the proposed method,by using the Verasonics platform.Simulation,phantom(Sawbones),and ex-vivo experiments validate the effectiveness of the method.Notably,the average error of the thickness is less than 0.2 mm,and the relative error is less than 7%for both three-layer and fivelayer cortical bone.The influence of the number of plane wave compounding angles on imaging quality is investigated,revealing that only 15 angles are sufficient to produce high-quality images.The influence of the velocity model on imaging accuracy is also examin

关 键 词：平面波成像 皮质骨 多层介质 频域 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] R318[自动化与计算机技术—计算机科学与技术]