Feasibility study of CCD-based gamma camera

Conventional gamma cameras which uses photomultiplier tubes(PMT) is very heavy, bulky, and expensive. In addition, its spatial resolution is low because of geometrical limitation of PMTs. This low resolution and large size is not efficient for the small animal imaging system which is useful in preclinical imaging application. We have developed a small size but high spatial resolution gamma ray detector, based on charge-coupled device(CCD) which is useful to develop a prototype model of small animal gamma camera. Recently the sensitivity of CCD was improved and the peltier cooling system helped to minimize the dark currents of CCD significantly. The enhanced sensitivity and high intrinsic resolution of CCD enabled researchers to develop the small size gamma camera with low cost. In this study we used peltier cooled CCD sensor which has about 70% of quantum efficiency at 650nm wave length. CsI(Tl) scintillator was also used to convert the gamma ray to visible lights. These light photons from the scintillator have been collected to the CCD surface by Nikorr macro lens to enhance the collection efficiency. The experimental results showed that the proposed CCD-based detection system is feasible for gamma ray detection.