I actually had a mild (albiet very mild) concussion from it, they did the cat scan because i broke playing ultimate Frisbee when 2 people collided with me and then i went down. I also just asked my mother about this, she is a nurse she says that, her hospital at least, has a policy that all head injuries get some form of a test (usually a cat scan) done, i guess this prevents frivolous law suits if they would happen to miss something,you can refuse but you can refuse any service as long as your in a right state of mind, but then the hospital can't be held accountable because it was your choice. I would consider this a good indication about our society and how mistakes are punished to the point it hurts people and makes legitimate claims look bad. or as most people call it, we're a sue crazy society....