The GP I saw told me that a MRI or CT scan will show if there's bleeding in the brain, basically if you are going to die. Lesser damage will not show up, she said.

My concussion happened in 2011, and the headaches got so bad a few months ago (throwing up) that I went to see a head trauma specialist. She showed me the CT scan of my brain in 3d and where blood buildup would be (on the outside near the edge of the skull), and there was just a thin layer as should be. But they did find other things. So even though it didn't help diagnose my concussion, it incidentally found other things (as someone else also posted about above).

If its only $450 cost to you, I'd do it, that's a bargain IMO. Mine was $1200 cost to me through insurance in 2011 ($3800 total bill) and its gone up since. Although if I knew how worthless MRI/CT scans were to this condition, I wouldn't have had it done (though I would have missed out on the other things).