Search for: [Abstract = "This is indispensable in order to be able to perform reliable quantitative analysis of SPECT images. It is also especially important in non\-hybrid gamma cameras, where not all physical processes that disturb image acquisition can be easily corrected. Two experiments with an 131\"I\" point source placed at different distances from the detector plane were performed allowing the detector response to be acquired as a function of the point source distance. An analytical Gaussian function was fitted to the acquired data in both the one\- and the two\-dimensional case."]