Nuclear medicine techniques (such as SPECT) have the potential to become powerful new tools in imaging biological processes in small laboratory animals. With the every increasing number of human disease models, particularly in the smaller animals such as mice and rats, the potential of high resolution nuclear medicine nuclear medicine technologies to contribute unique information is becoming apparent to many researchers. Clinical radionuclide systems are not suitable for imaging small animals because their spatial resolution is not adequate. This makes commercial SPECT systems are not suitable for imaging small animals because their spatial resolution is not adequate. This makes commercial SPECT systems unsuitable for resolving millimeter- sized structures in mice. Hence, dedicated, low cost instruments are required for conducting small animal studies with higher spatial resolution than what is current achieved with clinical SPECT scanners. The goal of the proposed research is to investigate a novel position sensitive detector concept for small animal SPECT imaging. The proposed approach is expected to provide high spatial resolution, and the system is expected to be simpler and lower in cost as compared to other approaches being investigated. Nuclear medicine including positron emission tomography, and single photon emission computed tomography, radiology, non-destructive testing, materials research, X-ray diffraction, nuclear and high energy physics research, astronomy, and geological exploration.