When you go to the doctor, you want to find out what's wrong and how you can get better. In modern-day America, though, what you will get are tests to "rule out" problems rather than figure out what you actually have.
CT examinations, like all medical tests, should be performed only when medically required. The results of the proposed CT or any imaging examinations should answer a clinical question and either confirm or exclude a suspected condition.
There is very little in medicine (or in life) that is risk-free. And there are very few clear-cut answers in medicine. All of us, doctors and patients and parents alike, weigh risks and benefits differently.