@Pregnantandvworried its just because your uterus is nowhere near the primary beam where the radiation ‘energy’ is high.
our hospital asks pregnancy status for chest scans (and all abdo/pelvis/upper thigh scans) but never for heads,
for scans where we do ask, our policy is ask LMP, plus whether there is any chance of pregnancy, and state that we are asking because we are using radiation and that there could be a potential risk to a fetus (during scans that could irradiate close to the pelvis)
we equally don’t ask for anything knee down, as the pelvis is deemed far enough from the beam to not be necessary.
we scan pregnant heads all the time (clot risks make them a common exam), chests too for the same reason, but we’d wrap lead round her tummy for a chest as the pelvis area is much closer to the bottom of your chest than your head - we don’t for a head though.
the statement ‘there is always a risk’ is standard. It’s horrible to have to explain it to ladies that way when they are worried about their own health vs that of their baby, but it is partly as they obviously can’t ever experiment on pregnant women to quantify if there is a true risk.
we are all exposed to background levels of radiation all the time though, even more if you take a flight.
hopefully the radiation protection supervisor can answer your worries, just thought some info might be of some help, so you don’t feel baffled during a phone call.