Coincidence measurements with a quasi-continuous detector for small animal PET

The authors have previously designed and constructed a single-plane small-animal PET instrument with spatial resolution of approximately 1 mm. A volumetric block design, a generalization of the single plane designs that does not use individual crystal elements in both dimensions, has been generated. The novel characteristic of this design is that the crystal elements are discrete in the transaxial dimension and continuous in the axial dimension allowing for easy fabrication and low light losses. The singles response of this design has been previously characterized. The purpose of the work reported here was to establish methodology for the correction of non-uniformities in the singles block responses and to apply them to simple coincidence measurements in order to demonstrate their effect