What is Oxygen-18? and why it is being used?

Oxygen-18 (18O) is a natural, stable isotope of oxygen and it is supplied in the form of Oxygen-18 water (H218O).

18O water has many applications in Paleoclimatology, Hydrology, Plant physiology and the radiopharmaceutical industry. 18O is an important precursor for the production of fluorodeoxyglucose (FDG) used in positron emission tomography (PET), which is a common nuclear medicine imaging technique. Generally, enriched water (H218O) is bombarded with hydrogen ions in either a cyclotron or linear accelerator creating fluorine-18. Fluorine-18 is an important isotope in the radiopharmaceutical industry, and is primarily synthesized into FDG, which is injected into a patient’s body for use in PET scans.

In normal oxygen (oxygen-16), there are 8 protons and 8 neutrons.

In Oxygen-18:

Protons: 8; Neutrons:10

Oxygen-18 natural abundane: 0.2%