A Design of a New Readout Sensor for SPECT

72486-With the ever increasing number of smaller animals, such as mice and rats, being used as human disease models, the demand for small animal imaging also has increased. In particular, the pharmaceutical industry requires the in vivo quantification of biological processes, to measure the mechanism of action of a pharmacological agent and its concentration at the site of action. High-resolution nuclear imaging technologies such as single photon emission computed tomography (SPECT) has the potential to contribute unique information at these finely-graded levels. However, the main barriers to using SPECT in studies of laboratory animals have traditionally been poor spatial resolution, low sensitivity, and high cost. To address these deficiencies, this project will develop a novel detector based on a new, position-sensitive readout coupled to a microcolumnar scintillator, leading to a SPECT detector that can achieve extremely fine spatial resolution and high sensitivity in a cost-effective manner. Phase I demonstrated the feasibility of developing a high resolution, high efficiency SPECT detector module based on a new charge coupled device (CCD). Accomplishments included the development of a 3 mm thick microcolumnar scintillator film, construction of a digital imaging detector based on a special CCD, and radionuclide imaging using this detector/scintillator in a realistic SPECT environment. Phase II will develop a prototype digital detector based on the aforementioned technologies for SPECT imaging. The detector will consist of a thick microcolumnar scintillator optically coupled to the novel CCD via a fiberoptic taper, and a specially designed tungsten collimator. When completed, the detector will provide a 5 cm x 5 cm imaging area, an intrinsic spatial resolution of 100 microns or lower, and a high detection efficiency for gamma ray energies typically used in SPECT at a relatively low cost. Commercial Applications and Other Benefits as described by awardee: The new detector design should have widespread use in new small animal/human SPECT systems in particular and nuclear medicine systems in general. Additionally, the readout sensor should have applications in high sensitivity x-ray imaging, bioluminescence imaging, nondestructive testing, etc.