光声成像是一种新兴的无损生物医学成像方法,因其兼具高灵敏的光学对比度和超声能够对深层组织进行高分辨成像的优点,已经成为当前生物医学成像领域发展最快的技术之一.光声成像的光吸收对比度能够反映生物组织微小的组织病变,与血氧饱和度等多种功能和生理信息紧密相关,目前已被证明在肿瘤血管新生研究、早期癌症检测和心血管疾病诊断等方面有很大的应用潜力.基于超声阵列探测的常规光声计算层析成像系统,数据采集量大,由此导致的较低数据采集和成像速度成为制约该技术临床应用和转化的重要因素.压缩感知理论可以在远低于Nyquist采样定理的欠采样方式下,高质量重建信号,已被广泛用于信号处理和传统的医学图像重建领域.自2009年压缩感知理论被应用于光声成像以来,已有的研究结果表明,该方法为解决目前大区域光声成像的数据采集和成像速度问题提供了一条有效的途径.本文将重点介绍压缩感知理论用于光声成像的基本原理、研究现状、面临的问题和应用前景.%Photoacoustic tomography ( PAT ) is a novel noninvasive biomedical imaging modality that combines rich optical contrast with high ultrasonic resolution at depths up to several centimeters. The extremely high sensitivity of PAT to optical absorption can reveal a variety of important functional and physiological parameters-including single-vessel oxy-genation and oxygen metabolism-and thus may detect incipient neoplasia at a very early stage. So far, PAT has been demonstrated with broad potential applications in tumor angiogenesis imaging, early cancer detection, and the diagnosis of cardiovascular disease. However, in conventional photoacoustic tomography with ultrasonic-array detection, the a-mount of acquired data is huge, which has limited the speed of image acquisition, transmission, and display, as well as the clinical translation of PAT. Compressed sensing ( CS ) is capable of recovering compressible signals with under-sam- pled measurements ( sampling rate lower than the Nyquist rate ); it has been widely used in signal processing and traditional medical imaging areas. Since 2009, a number of CS-based photoacoustic image acquisition and reconstruction methods have been developed for PAT, leading to exciting results suggesting that CS mayt be an effective way for improving the imaging speed and reducing the cost of PAT. In this review, the basic principles of CS-based PAT, its current research status, challenges, and potential applications are addressed to provide an overview of this emerging area.
展开▼
