The geometric transfer function for cone and fan beam collimators

Abstract
Geometric response functions are derived for both cone and fan beam collimators for the scintillation camera. The formulation is based on an effective response function which is determined by the geometric response of a single hole. The technique provides an accurate description of the spatial resolution by characterising the complete geometric response function which includes the effects of the shape and orientation of the collimator holes. The theoretical formulation was used to design a fan beam collimator for SPECT imaging and was shown to agree well with the experimental results.