Assertion: radioactive fluorine | /r/HasProperty | key ingredient
Facets:
value: in positron emission tomography
type: LOCATION
value: in pet
type: LOCATION
Source sentences:
text: And radioactive fluorine (18F rather than the naturally-occurring 19F) is a key ingredient in positron emission tomography (or PET), a whole-body imaging technique that allows cancerous tumours to be discovered before they spread.