The most commonly used PET-CT imaging agent such as 18F-FDG has a half-exclusion period of only 108 minutes, i.e. less than 2 hours, and is automatically reduced by half when placed outside. After it is used inside the body, the body still has a functional state of self-clearance and excretion, so it is called biological half-exclusion period. After the PET-CT imaging, the residual imaging agent in the body will be metabolized soon. The International Atomic Energy Agency has given a clear basis that a pregnant woman can breastfeed her child 4 hours after PET-CT. So you don’t need to be too nervous and you can go home to live completely.