Following the pioneering work of the Hungarian George de Hevesy, Nobel Laureate (1943) for working out a radioactive tracing system, medical imaging has been much aided by the use of medical isotopes to determine the function of internal organs. Hevesy determined the phosphor metabolism by radioactive nuclides.
Compounds can be labeled with radioactive isotopes (such as technetium-99m and thallium-201) or radio-opaques (such as barium and iodine compounds).
Radio-labelled compounds can be tracked by gamma-detecting cameras to provide useful images of organs to which they are transported. In 1935, Hevesy worked on tracing the synthesis of biological molecules using radioactive isotopes, such as 32P.
The MRI images display cross-sectional images of the examined body part, and the smallest deformations are easy to detect.
In 1977, magnetic resonance was successfully used to study human organs. Magnetic isotope diagnostics provides invaluable help in diagnosing a high number of organic deformations and severe illnesses.