[en] Explorations of Nuclear Medicine require administration of a radioactive compound having a tropism for an organ or a group of cells with a specific physiology or metabolism. Visualization of a radioactive pattern is performed by the detection of gamma rays and their transformation by a NaI crystal and photomultiplier tube into an electric signal. Devices used had a tremendous evolution for twenty years passing a ponctual to a surface detector (ß Camera) having a constant unproving of sensitivity and resolution and allowing by rotating a three dimension detection and computerized ß and ß⁺ tomographies