Study of the resolution performance of an array of discrete detectors with independent readouts for positron emission tomography

The intrinsic resolution characteristics of an original detection system for very high resolution positron emission tomography (PET) based on arrays of small discrete crystals individually coupled to solid state photodetectors are evaluated. The results obtained demonstrate the excellent three-dimensional (3-D) resolving capability of a detection system based on the EG&G/RCA C30994 detector module. The analysis of the various components contributing to the resolution has shown that the geometry of the detector and the intercrystal scattering both contribute to limit the achievable intrinsic resolution. The geometrical component is dominant off the central region of the camera field as a result of intercrystal penetration when the array is irradiated at an angle. Intercrystal scattering must be properly rejected to achieve the intrinsic resolution determined by the detector geometry