How to radioisotope dating
In Australia there are about 560,000 per year, 470,000 of these using reactor isotopes.
The use of radiopharmaceuticals in diagnosis is growing at over 10% per year.
These may occur naturally, as in the cases of radium and uranium, or may be created artificially.
Single photon emission computerised tomography (SPECT) is the current major scanning technology to diagnose and monitor a wide range of medical conditions.
A more recent development is positron emission tomography (PET) which is a more precise and sophisticated technique using isotopes produced in a cyclotron.
These are detected by a PET camera and give very precise indications of their origin.
PET's most important clinical role is in oncology, with fluorine-18 as the tracer, since it has proven to be the most accurate non-invasive method of detecting and evaluating most cancers. New procedures combine PET with computed X-ray tomography (CT) scans to give co-registration of the two images (PET-CT), enabling 30% better diagnosis than with a traditional gamma camera alone.
Nuclear medicine was developed in the 1950s by physicians with an endocrine emphasis, initially using iodine-131 to diagnose and then treat thyroid disease.