The aim of our research was to develop an algorithm for estimation and visualisation of radiopharmaceutical uptake based on time-activity-curve (TAC) analysis in small regions of interest (ROI) in scintigraphic studies. The algorithm is implemented in Labview environment (National Instruments, Texas, Austin) and comprises the following steps: 1) delineation of grid of small ROIs over the examined tissue and corresponding TAC processing; 2) background vs tissue separation; 3) the extraction of all “suspected“ ROIs where TACs are not exponentially descendent; 4) correlation analysis between a TAC corresponding to the suspicious lesion ROI and TACs of neghboring ROIs; 5) the extraction of representative TAC for “suspected“ area by Principal Component Analysis technique; and 6) visual interpretation of radiopharmaceutical distribution in the “suspected“ area. The application of algorithm is presented in data recorded in case of histopathologically proven parathyroid tumors