Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States of America.
PLoS One. 2012;7(8):e43999. doi: 10.1371/journal.pone.0043999. Epub 2012 Aug 27.
Photoacoustic tomography (PAT) is a molecular imaging technology. Unlike conventional reporter gene imaging, which is usually based on fluorescence, photoacoustic reporter gene imaging relies only on optical absorption. This work demonstrates several key merits of PAT using lacZ, one of the most widely used reporter genes in biology. We show that the expression of lacZ can be imaged by PAT as deep as 5.0 cm in biological tissue, with resolutions of ∼1.0 mm and ∼0.4 mm in the lateral and axial directions, respectively. We further demonstrate non-invasive, simultaneous imaging of a lacZ-expressing tumor and its surrounding microvasculature in vivo by dual-wavelength acoustic-resolution photoacoustic microscopy (AR-PAM), with a lateral resolution of 45 µm and an axial resolution of 15 µm. Finally, using optical-resolution photoacoustic microscopy (OR-PAM), we show intra-cellular localization of lacZ expression, with a lateral resolution of a fraction of a micron. These results suggest that PAT is a complementary tool to conventional optical fluorescence imaging of reporter genes for linking biological studies from the microscopic to the macroscopic scales.
光声断层摄影术（PAT）是一种分子成像技术。与通常基于荧光的传统报告基因成像不同，光声报告基因成像是仅依赖于光吸收的。这项工作展示了 PAT 在使用 lacZ（生物学中最广泛使用的报告基因之一）方面的几个关键优点。我们表明，lacZ 的表达可以通过 PAT 在生物组织中成像深达 5.0 厘米，横向和轴向分辨率分别约为 1.0 毫米和 0.4 毫米。我们进一步通过双波长声学分辨率光声显微镜（AR-PAM）证明了对表达 lacZ 的肿瘤及其周围微血管的非侵入性、同时体内成像，横向分辨率为 45 µm，轴向分辨率为 15 µm。最后，使用光学分辨率光声显微镜（OR-PAM），我们显示了 lacZ 表达的细胞内定位，具有亚微米级的横向分辨率。这些结果表明，PAT 是传统光学荧光报告基因成像的互补工具，用于将生物研究从微观尺度连接到宏观尺度。
