The aim of this paper is to present the functionality and clinical application of developed GammaKey software for nuclear medicine imaging. GammaKey software consists of image acquisition module (compatibile with semi-analog gamma cameras), database, image processing module and network communication module. This software prolonged life of old gamma cameras, but also enabled image processing of DICOM data from modern gamma cameras. This paper emphasizes the importance of GammaKey application in clinical practice through several examples.Keywords -dynamic parathyroid scintigraphy, nuclear medicine imaging, platelet kinetics, platelet life span.