GEOMETRICAL RESPONSE OF MULTIHOLE COLLIMATORS

A complete theory of camera multihole collimators is presented. The ge ometrical system response is determined in closed form in frequency sp ace. This closed form accounts for the known efficiency and resolution formulae for parallel beam, fan beam, cone beam and astigmatic collim ators as well as for the most frequent hole array patterns and hole sh apes. The point spread function in the space domain for a certain coll imator and source position can be calculated via a discrete fast Fouri er transform. Beside the complete theoretical definition of the respon se of multihole collimators, this theory allows the definition of accu rate models of the geometrical response for SPECT reconstruction and i t is suitable for designing new collimators.