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.
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.
Phosphorus - 30 decays by ejecting a positron and has a half-life of about 3 minutes.
The positron has not been mentioned before because it does not occurring natural radioactivity.
For groundwater, this means that C is a widely used tool to establish chronologies for groundwater flow systems and climate records for the Holocene and Pleistocene.
It is considered to be the most important tool for age dating of ‘old’ groundwater.
A nuclide is any species of atom of which each atom has an identical proton number and also an identical nucleon number.
The thyroid, bones, heart, liver and many other organs can be easily imaged, and disorders in their function revealed.
In some cases radiation can be used to treat diseased organs, or tumours.
The stable and non-radioactive elements can also be changed into radioactive elements by bombarding them with protons, neutrons or alpha particles.
Such artificially produced radioactive elements are called radioactive isotopes or radioisotopes.