Abstract: A compact medical nuclear imaging device, which generates a medical image from gamma radiation, can be held stationary or moved to search a large area for locating a radioactive area of interest. The compact medical imaging device comprises a collimator having an array of collimating channels, a radiation collection module converting the gamma radiation to an electric signal, an electronic module for processing the electrical signal, and a display module for displaying a two-dimensional image of the radiation scene, all of which preferably are assembled together in a single, compact module of a size small enough to permit it to be held and maneuvered by a human operator.