This is a branch of medicine that uses radiation to provide information about the functioning of a person's specific organs or to treat disease.
In most cases, the information is used by physicians to make a quick, accurate diagnosis of the patient's illness.
Five Nobel Laureates have been intimately involved with the use of radioactive tracers in medicine.
Over 10,000 hospitals worldwide use radioisotopes in medicine, and about 90% of the procedures are for diagnosis.
The most common radioisotope used in diagnosis is technetium-99, with some 35 million procedures per year (16.7 million in USA in 2012, 550,000 in Australia), accounting for about 80% of all nuclear medicine procedures worldwide.
In developed countries (26% of world population) the frequency of diagnostic nuclear medicine is 1.9% per year, and the frequency of therapy with radioisotopes is about one tenth of this.
North America is the dominant market for diagnostic radioisotopes with close to half of the market share, while Europe accounts for about 20%.
Nuclear medicine was developed in the 1950s by physicians with an endocrine emphasis, initially using iodine-131 to diagnose and then treat thyroid disease.In recent years specialists have also come from radiology, as dual CT/PET procedures have become established, Computed X-ray tomography (CT) scans and nuclear medicine contribute 36% of the total radiation exposure and 75% of the medical exposure to the US population, according to a US National Council on Radiation Protection & Measurements report in 2009.In the USA there are over 20 million nuclear medicine procedures per year among 311 million people, and in Europe about 10 million among 500 million people.In Australia there are about 560,000 per year among 21 million people, 470,000 of these using reactor isotopes.The use of radiopharmaceuticals in diagnosis is growing at over 10% per year.The global radioisotope market was valued at .8 billion in 2012, with medical radioisotopes accounting for about 80% of this, and is poised to reach about billion by 2017.