positron-emission tomography
noun
: tomography in which a cross-sectional image of regional metabolism is obtained by a usually color-coded representation of the distribution of gamma radiation given off in the collision of electrons in cells with positrons emitted by radionuclides incorporated into metabolic substances that have been administered (as by injection)
Example Sentences
Recent Examples on the Web In the new study, the authors used positron-emission tomography to scan immune system activity in mice that had the blood in a single cerebral artery interrupted for 45 minutes, mimicking an ischemic stroke. 
Bret Stetka, Scientific American, 2 July 2019
Bret Stetka, Scientific American, 2 July 2019 Word History
First Known Use
1976, in the meaning defined above
Medical Definition
positron-emission tomography
noun
: tomography in which an in vivo, noninvasive, cross-sectional image of regional metabolism is obtained by a usually color-coded cathode-ray tube representation of the distribution of gamma radiation given off in the collision of electrons in cells with positrons emitted by radionuclides incorporated into metabolic substances —abbreviation PET