My son had a CT scan when he was 5. They told me it would be ok to try without sedation (I thought he would do fine) and then sedate him if needed. I explained everything to him...but when we got in there and he saw the machine, he was so scared (I don't know why), he begged me to have them put him to sleep. He was already going to get stuck with a needle anyway because they were using contrast with him. Anyway, I would say try it without if that is what you feel comfortable with.