Why would they not have been able to put a metal plate in his head?
Exactly. Maybe he could use one of these:
Pancake?
Eddie: "Well, don't go putting none of that stuff on my sled Clark. You know that metal plate in my head?"
Clark: "Ah! How could I forget?"
Eddie: "I had to have it replaced, because everytime Cathrine revved up the microwave, I'd piss my pants and forget who I was for about a half-hour or so.
National Lampoon's Christmas Vacation
They don't put 'metal' plates in anymore. Metal badly degrades imaging by CAT scan. And if it's ferrous, it would be sucked out by a MRI. The starburst artifact from GSW's are really cool during imaging. Too many years as a CT tech in Level 1 Trauma centers in Detroit gave me a quite a collection of neat pictures.