分层媒质中的分步相位偏移光声成像方法  

Split step phase shift migration based photoacoustic imaging in heterogeneous medium

作　　者：刘思宇 王云石 阚威威 LIU Siyu;WANG Yunshi;KAN Weiwei(Southwest Institute of Technical Physics,Chengdu 610041;School of Physics,Nanjing University of Science and Technology,Nanjing 210094)

机构地区：[1]西南技术物理研究所,成都610041 [2]南京理工大学物理学院,南京210094

出　　处：《声学学报》2024年第3期392-397,共6页Acta Acustica

基　　金：国家自然科学基金项目(12204242);四川省中央引导地方科技发展资金项目(2023ZYD0018);江苏省自然科学基金项目(BK20210323)资助。

摘　　要：为了解决波场外推方法在横向声速不均匀的分层媒质中图像重建能力受限的问题,提出了一种基于分步相位偏移的不规则分层媒质光声成像方法。该方法将横向声速差异等效为分层媒质界面处的扰动声源,利用该扰动声源对相位偏移的结果进行额外的校正偏移,并采用变步长的混合外推机制,实现光声波场的逐层外推重建。仿真模拟及实验结果均表明,分步相位偏移方法能够有效抑制不规则分层媒质光声成像中伪影的产生,并提升成像分辨率以及图像对比度。To address the limited image reconstruction capability of the wavefield extrapolation method in heterogeneous layered media with nonuniform lateral sound speed,split step phase shift migration based photoacoustic imaging in heterogeneous medium is proposed.This method treats the lateral sound speed difference as an equivalent perturbation sound source at the interface of the layered medium.Such a virtual perturbation sound source can be used to generate additional corrective phase shifts on the reconstructive acoustic field.By employing a hybrid extrapolation mechanism with variable step size,layer-by-layer reconstruction of the photoacoustic wave field can be achieved.Both simulation and experimental results demonstrate that the proposed split step phase shift migration method can effectively suppress the generation of artifacts in photoacoustic imaging in irregular layered media,enhance image resolution,and improve image contrast.

关 键 词：光声成像 分层媒质成像 相位偏移 波场外推 

分 类 号：R318[医药卫生—生物医学工程] TP391.41[医药卫生—基础医学]