Cai De, Li Zhongfei, Chen Sung-Liang
University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China.
Biomed Opt Express. 2016 Jan 7;7(2):369-80. doi: 10.1364/BOE.7.000369. eCollection 2016 Feb 1.
Acoustic-resolution photoacoustic microscopy (ARPAM) provides a spatial resolution on the order of tens of micrometers, and is becoming an essential tool for imaging fine structures, such as the subcutaneous microvasculature. High lateral resolution of ARPAM is achieved using high numerical aperture (NA) of acoustic transducer; however, the depth of focus and working distance will be deteriorated correspondingly, thus sacrificing the imaging range and accessible depth. The axial resolution of ARPAM is limited by the transducer's bandwidth. In this work, we develop deconvolution ARPAM (D-ARPAM) in three dimensions that can improve the lateral resolution by 1.8 and 3.7 times and the axial resolution by 1.7 and 2.7 times, depending on the adopted criteria, using a 20-MHz focused transducer without physically increasing its NA and bandwidth. The resolution enhancement in three dimensions by D-ARPAM is also demonstrated by in vivo imaging of the microvasculature of a chick embryo. The proposed D-ARPAM has potential for biomedical imaging that simultaneously requires high spatial resolution, extended imaging range, and long accessible depth.
声学分辨率光声显微镜（ARPAM）提供了几十微米量级的空间分辨率，正成为成像精细结构（如皮下微血管系统）的重要工具。ARPAM的高横向分辨率是通过使用高声学数值孔径（NA）的换能器实现的；然而，焦深和工作距离会相应变差，从而牺牲成像范围和可及深度。ARPAM的轴向分辨率受换能器带宽限制。在这项工作中，我们开发了三维去卷积ARPAM（D-ARPAM），使用20兆赫兹聚焦换能器，在不实际增加其NA和带宽的情况下，根据所采用的标准，可将横向分辨率提高1.8倍和3.7倍，轴向分辨率提高1.7倍和2.7倍。通过鸡胚微血管系统的体内成像也证明了D-ARPAM在三维上的分辨率增强。所提出的D-ARPAM在同时需要高空间分辨率、扩展成像范围和长可及深度的生物医学成像方面具有潜力。
