Introduction: The phenomenon of radioactivity was discovered in 1896 by Antoin Henri Becquerel, but its application in visual diagnostics started about fifty years later.
Rectilinear scanner: It was constructed by B. Cassen and ass. in 1949, when first scintiscans were obtained. Technical improvements have been made 1950-1956 (B. Cassen and ass., R. Newall and ass., P. Bell, D. Kuhl). Soon after appearance of the first Cassen's scanner, commercial production began.
Gamma camera: It was invented and constructed by H. Anger in 1957, improvements being made from 1958 to 1963. Gamma cameras are being commercially produced and sold since 1962; about ten years later they become widely used, and soon they pushed out the scanner from visual diagnostics. COMPUTER: Its use in scintigraphic diagnostics started in 1964 (H. Shepers, D. Wincler, D. Brown). From 1965 to 1974 various centers developed their own computer programs; after 1974 computers with incorporated nuclear medicine software packages became commercially available.
Tomoscintigraphy (spet) and positron tomography (pet): Numerous attempts to obtain tomographic images of organs using scanners and gamma cameras were made between 1963 and 1973 (D. Kuhl and R. Edwards, H. Anger, N. Charkes and R. Somburanasin et al.). The concept of contemporary single photon emission tomography (SPET) device was developed between 1974 and 1977 (J. Keyes and ass. and R. Jaszczak and ass.), while commercial production started in 1982. First cyclotrons for production of positron emitters, a prerequisite for positron emission tomography (PET) diagnostics, emerged in hospitals in 1955, and in last ten years they are being commercially made for these purposes. H. Anger (1959), M. Phelps, E. Hoffman and M. Ter-Pogossian (1975) set the grounds of PET; commercial production of PET systems started thereafter.
Conclusion: Visual diagnostics in nuclear medicine reached its zenith in clinical practice during 1970-1980. It is partly pushed into the background by new imaging techniques (US, CT, MRI), but it only initiated further improvements (SPET, PET).