Direct Imaging of Radionuclide-Produced Electrons and Positrons with an Ultrathin Phosphor

Journal of Nuclear Medicine

Lisa S. Gobar¹  Liying Chen¹  Arthur F. Gmitro¹  Harrison H. Barrett¹  Negar G. Knowles¹  Zhonglin Liu¹ 

关键词: electron imaging;    CCD;    phosphor;    in vivo imaging;    positron;   

DOI  :  10.2967/jnumed.107.040568

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Current electron detectors are either unable to image in vivo or lack sufficient spatial resolution because of electron scattering in thick detector materials. This study was aimed at developing a sensitive high-resolution system capable of detecting electron-emitting isotopes in vivo. Methods: The system uses a lens-coupled charge-coupled-device camera to capture the scintillation light excited by an electron-emitting object near an ultrathin phosphor. The spatial resolution and sensitivity of the system were measured with a 3.7-kBq 90Y/90Sr β-source and a 70-μm resin bead labeled with 99mTc. Finally, we imaged the 99mTc-pertechnetate concentration in the mandibular gland of a mouse in vivo. Results: Useful images were obtained with only a few hundred emitted β particles from the 90Y/90Sr source or conversion electrons from the 99mTc bead source. The in vivo image showed a clear profile of the mandibular gland and many fine details with exposures of as low as 30 s. All measurements were consistent with a spatial resolution of about 50 μm, corresponding to 2.5 detector pixels with the current camera. Conclusion: Our new electron-imaging system can image electron-emitting isotope distributions at high resolution and sensitivity. The system is useful for in vivo imaging of small animals and small, exposed regions on humans. The ability to image β particles, positrons, and conversion electrons makes the system applicable to most isotopes.

【 授权许可】

Unknown