You were sent to the ER so that a doctor could look for symtoms that would alert them to the need for a scan. They saw no reason to do one, and in both intances, it seems like they were right.
There is no reason to subject someone to an expensive test to rule out an injury for which there was no symptom, these are extreemly expensive tests and are not without risk because of the radiation exposure. If there were any symptom present when the doctor did the exam (they look at things like balace, eyes, consiousness, etc) they would do a scan in a heartbeat because they don't want to miss something. An injury alone is not one of the symtoms they are looking for, it is a reason to be evaluated.
Natasia Richardson had symptoms that would have caused an ER doctor to scan her had she been in an ER and not her hotel room, she was not taken to the ER until well after the symptoms developed. You would not have waited if your son was symtomatic because her experience brought this subject noteriety. That was the lesson, to recognize how serious the symptoms are, not that every hard bump requires a scan.
You did the right thing to get your children evaluated, but what happend was both normal, and right, as it turns out and it happens all the time. We had the top bar of a swing set fall and hit our child in the head, she required 8 staples, but while she was there, they were most concerned about the posility of a head injury, so she was taken back from triage to a room right away. After 90 minutes in the ER, and the staples, they never did a scan because she had no symptoms that required it. We were sent home with specifc instructions of what to look for and to come back right away if we saw any. I had a time clock fall of the wall at work and hit me in the nose (long story) it broke my nose, but the ER was most concerned about a posible head injury, no symptoms, no scan, also sent home with instructions. Not only is it normal, it is common.
M.