血管内光声图像的建模与仿真

Modeling and simulation of intravascular photoacoustic images

为了给血管内光声(intravascular photoacoustic,IVPA)成像的图像重建算法和图像后处理算法提供数据源,为培训医师提供图像库,提出一种二维IVPA图像的建模与仿真方法。建立包含斑块的血管横截面模型,并对成像导管发射激光脉冲照射血管壁组织、血管壁组织产生光声信号、利用得到的一组光声信号重建IVPA图像整个过程进行仿真,得到血管横截面模型的二维IVPA灰阶图像,同时根据冠状动脉血管随心脏搏动的规律,实现序列图像的仿真。利用仿真模型得到的IVPA图像与原电磁吸收分布图接近程度较高。仿真模型的物理意义清晰,可得到质量稳定的IVPA图像。

A model for simulating two-dimension （2D） intravascular photoacoustic （IVPA） images is proposed to provide image data sets for developing algorithms of image reconstruction and post-processing and training clinical physicians. The multi-layered luminal cross-sections are firstly modeled. Then, the process of light propagation in multi-layered tissues, generation of photoacoustic signals, and reconstruction of gray-scale images are simulated obtaining 2D gray- scale IVPA images. The sequential IVPA images are also simulated based on the pulsatile dynamics of coronary arteries during the cardiac cycles. There are few differences between simulated images and electromagnetic absorption profiles. The model had a clear physical meaning, and could simulate IVPA images with stable quality.