How can a cat scan be done on someone who is pregnant?

See below: 1st, they try to avoid doing a ct scan in the first place. If an alternative isn't available, then they shield the belly with lead to avoid radiation to the fetus. If the concern is in the abdomen or pelvis, some radiation will hit the fetus. But they'll use as little radiation (turn down power & duration of radiation) as much as possible. In an emergency, u have to treat the mom to save baby.