Abstract
Cerenkov luminescence imaging (CLI) can image radiopharmaceuticals using high-sensitivity charge coupled device (CCD) camera. However, Cerenkov luminescence (CL) emitted from the radiopharmaceuticals is weak and has low penetration depth in biological tissues, which severely limits the sensitivity and accuracy of CLI. This study presents the three-dimensional (3D) radiopharmaceutical excited fluorescence tomography (REFT) using europium oxide (EO) nanoparticles, which enhances the CL signal intensity, improves the penetration depth, and obtains more accurate 3D distribution of radiopharmaceuticals. Methods: The enhanced optical signals of various radiopharmaceuticals (including Na131I, 18F-FDG, 68GaCl3, Na99mTcO4) by EO nanoparticles were detected in vitro. The location and 3D distribution of the radiopharmaceuticals of REFT were then reconstructed and compared with those of Cerenkov luminescence tomography (CLT) through the experiments of the phantom, artificial source-implanted mouse models, and mice bearing hepatocellular carcinomas (HCCs). Results: The mixture of 68GaCl3 and EO nanoparticles possessed the strongest optical signals compared with the other mixtures. The in vitro phantom and implanted mouse studies showed that REFT revealed more accurate 3D distribution of 68GaCl3. REFT can detected more tumors than small animal positron emission tomography (PET) in HCC bearing mice and achieved more accurate 3D distribution information compared with CLT. Conclusion: REFT with EO nanoparticles significantly improves accuracy of localization of radiopharmaceuticals and can precisely localize the tumor in vivo.
- Animal Imaging
- Molecular Imaging
- Optical
- Cerenkov luminescence imaging
- europium oxide nanoparticles
- radiopharmaceutical excited fluorescence
- tomography
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.