1. A method of enhancing quality of a planar image acquired by a detector in single photon emission imaging of a portion of a body or at least one specific organ or volume of interest located within the portion of the body, the portion of the body administered with radio-harmaceutical substance radiating gamma rays, the method comprising: selecting, for each pixel of the acquired planar image at least one selected distance from the detector, forming a set of effective distances, said set having at least one effective distance; calculating, for each pixel, weight values utilizing acceptance angles of the gamma camera detector and the said at least one selected distance of the set of effective distances; constructing a two dimensional image of a spatial distribution of the pharmaceutical substance within the portion of the body by mathematically analyzing said data in conjunction with the weight values.