School of Physics, Nanjing University of Science and Technology, Nanjing 210094, China.
Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong 999077, China.
Sensors (Basel). 2024 Apr 23;24(9):2670. doi: 10.3390/s24092670.
Photoacoustic imaging (PAI) is a rapidly developing emerging non-invasive biomedical imaging technique that combines the strong contrast from optical absorption imaging and the high resolution from acoustic imaging. Abnormal biological tissues (such as tumors and inflammation) generate different levels of thermal expansion after absorbing optical energy, producing distinct acoustic signals from normal tissues. This technique can detect small tissue lesions in biological tissues and has demonstrated significant potential for applications in tumor research, melanoma detection, and cardiovascular disease diagnosis. During the process of collecting photoacoustic signals in a PAI system, various factors can influence the signals, such as absorption, scattering, and attenuation in biological tissues. A single ultrasound transducer cannot provide sufficient information to reconstruct high-precision photoacoustic images. To obtain more accurate and clear image reconstruction results, PAI systems typically use a large number of ultrasound transducers to collect multi-channel signals from different angles and positions, thereby acquiring more information about the photoacoustic signals. Therefore, to reconstruct high-quality photoacoustic images, PAI systems require a significant number of measurement signals, which can result in substantial hardware and time costs. Compressed sensing is an algorithm that breaks through the Nyquist sampling theorem and can reconstruct the original signal with a small number of measurement signals. PAI based on compressed sensing has made breakthroughs over the past decade, enabling the reconstruction of low artifacts and high-quality images with a small number of photoacoustic measurement signals, improving time efficiency, and reducing hardware costs. This article provides a detailed introduction to PAI based on compressed sensing, such as the physical transmission model-based compressed sensing method, two-stage reconstruction-based compressed sensing method, and single-pixel camera-based compressed sensing method. Challenges and future perspectives of compressed sensing-based PAI are also discussed.
光声成像是一种快速发展的新兴无创生物医学成像技术,它结合了光学吸收成像的强对比度和声学成像的高分辨率。异常的生物组织(如肿瘤和炎症)在吸收光能量后会产生不同程度的热膨胀,从而产生与正常组织不同的声学信号。该技术可检测生物组织中的小组织病变,在肿瘤研究、黑色素瘤检测和心血管疾病诊断方面具有重要的应用潜力。在光声成像系统中采集光声信号的过程中,各种因素会影响信号,如生物组织中的吸收、散射和衰减。单个超声换能器无法提供足够的信息来重建高精度的光声图像。为了获得更准确、更清晰的图像重建结果,光声成像系统通常使用大量的超声换能器从不同角度和位置采集多通道信号,从而获取更多关于光声信号的信息。因此,为了重建高质量的光声图像,光声成像系统需要大量的测量信号,这会导致大量的硬件和时间成本。压缩感知是一种突破奈奎斯特采样定理的算法,可以用少量的测量信号重建原始信号。基于压缩感知的光声成像在过去十年中取得了突破,能够用少量的光声测量信号重建低伪影、高质量的图像,提高了时间效率,降低了硬件成本。本文详细介绍了基于压缩感知的光声成像,如基于物理传输模型的压缩感知方法、基于两阶段重建的压缩感知方法和基于单像素相机的压缩感知方法。还讨论了基于压缩感知的光声成像的挑战和未来展望。