Tomorrow’s Tech Treepowered by Astra

Medicine · Recorded milestone

PET scanner

Recorded year1974

Michel Ter-Pogossian, Michael Phelps and Edward Hoffman build a ring scanner that tracks radioactive tracers, showing the body's chemistry at work.

Explore this milestone on the interactive map

Built on

Led to

Sources & evidence

Dataset updated 2026-10-18. This individual record has not been separately re-reviewed.