Robert Nason Beck (26 March 1928 in San Angelo, Texas – 6 August 2008 in Chicago, Illinois) was an American scientist and a pioneer in the field of nuclear medicine.
Part of a University of Chicago team, he was the first to propose, in 1961, the use of the radioisotope technetium-99m to detect disease using Single Photon Emission Computed Tomography, a technique that is used an estimated 20 million times a year throughout the world.
Beck also helped develop collimators for sharpening the images produced by gamma-ray scanners, and was referred to as 'Mr.