[Nuclear medicine in vivo and functional imaging. Historical perspective]

Nuclear Medicine is the application of radioactive materials to the diagnosis and treatment of patients and the study of human disease. The field had its beginning with the discovery of radioactivity by H. Becquerel in 1896 and the tracer principle proposed in 1913 by G. de Hevesy who used a naturally occurring radioactive isotope of lead to obtain information regarding certain aspects of calcium metabolism in plants. The actual development is more recent. F. and I. Joliot-Curie just after the discovery of the artificial radioactivity predicted in their visionary Nobel conference in 1935 the future applications of radioisotopes in biology and medicine. The development of Nuclear Medicine was made possible by the possibility of producing routinely the radioisotopes after World War II and by the development of suitable detectors: moving detector devices (scanners) then gamma cameras after 1957. Nuclear Imaging is today a unique tool for the in vivo investigation of the biochemical functioning of an organ. Two techniques are in rapid development, SPECT (single photon emission computed tomography) and PET (positron emission tomography).