My son needs a brain ct scan?

I think you're referring to an MRI, not a CT scan. The implant might interfere with the scan. I believe the reason for the scan is to determine the source of the motor tics. It could be psychiatric or neurological so an MRI would be best for observing nerve function.

There is no reason to remove an implant to do a CT.

There is the potential that an implant would make an MRI contraindicated, but I can't imagine any practitioner thinking that an imaging study is important enough to remove some kind of implanted hardware.

I do not believe you either but if it were true are you so damn dumb as to think they do not know how to deal with all these issues? Get real TROLL

What you are is a con man troll. You are putting out a sad story (not a question) and hope that some gullible idiot will try to contact you so that you can fleece them for as much as you can.

let them do it and they will take care of him

You need to talk to a counsellor. It is a very trying experience and it's okay to ask for support to help you through this time. My thoughts and best wishes are with you - hope it turns out okay.