A Direct comparison between in vivo optical imaging and PET imaging in mice

マウスにおけるインビボ蛍光イメージングとPETイメージングの同時比較

飯田 靖彦*; 花岡 宏史*; 渡辺 智; 石岡 典子; 渡邉 茂樹; 松橋 信平; Paudyal, B.*; 織内 昇*; 樋口 徹也*; 遠藤 啓吾*

Iida, Yasuhiko*; Hanaoka, Hirofumi*; Watanabe, Satoshi; Ishioka, Noriko; Watanabe, Shigeki; Matsuhashi, Shimpei; Paudyal, B.*; Oriuchi, Noboru*; Higuchi, Tetsuya*; Endo, Keigo*

Optical imaging is recently developed for in vivo molecular imaging. It requires only a simple system, and has advantage of relatively low cost. Furthermore, a probe for optical imaging can be designed to change its signal characteristic when it has interaction with the specific target. This property provides the highest signal-to-noise ratio for molecular targeting, so optical imaging is ideal candidate for molecular imaging. On the other hand, optical imaging is poor for tissue penetration and has limitation of deep tissue surveying. In this study, we prepared a probe, which labeled with both radioisotope and fluorescent dye, and evaluated the difference of images from PET and optical imaging, and compare the characteristics of both imaging methods. Anti-CD20 antibody, NuB2, was labeled with Cu and fluorescent dye. For in vivo imaging studies, tumor bearing mice were used. After administration of this probe, imaging was performed with PET and optical imaging. For the results, optical imaging could not detect deep tissue, so optical image was different from PET image. Compared with data from extracted tissue activity, optical image does not reflect the accurate tissue distribution, but it has utility for evaluation of subcutaneous transplanted tumor.