William H. Sweet and Gordon L. Brownell at Massachusetts General Hospital in Boston suggested using the radiation emitted by positron annihilation to improve the quality of brain images by increasing sensitivity and resolution. They published a description of the first positron-imaging device to record three-dimensional data of the brain in their 1953 paper Localization of brain tumors with positron emitters in Nucleonics XI. This was the beginning of positron emission tomography.
The beginning of Positron Emission Tomography
Discovering the positron