Their mass is converted to energy using

Einstein’s E=Mc2

positron and electron create two 511keV photonspositron and electron create two 511keV photons

180180

511k

eV

511k

eV

511 k

eV

511 k

eV

e

e

e

e e

e

ee e

e

e

e

e

ee

Positron is scattered by nearby electrons

Positron is emitted from FDG

in a cancer cell

After slowing down the positron

combines with an electron