Surprisingly few ER docs anywhere in the world have even a rudimentary understanding of the risks of CT scanning patients. There's a lot of information around about this, but my own first hand (anecdotal) experience is that I've had ER docs try to convince me that it's basically the same as an X-Ray and act like I'm a crazy person when I explain that it's orders of magnitude higher and cumulative over a lifetime. On one hand, it's not their job to care about your long term health - they need to rule out an emergency and get you out the door as quickly as possible - but it's very concerning.
It's a bit like how general practitioners aren't taught about nutrition at all, so give out really poor advice for heart disease patients (the leading cause of mortality in Western economies).