Whether braces need to be removed for a magnetic resonance imaging (MRI) scan depends on the area being scanned. The main problems with having an MRI with braces are that metal parts in the mouth may heat up under the scanner's magnet, and that their presence may affect the quality of the scan (giving a blurred image). If an MRI of the head is needed, the following must be removed: metal braces, ceramic braces with a metal slot (the middle part of the bracket), metal tubes (the brackets on the back teeth), metal archwires – both steel and nickel-titanium – orthodontic mini-implants and bonded wire retainers. Braces made of ceramic, plastic, sapphire or composite, as well as aligners and their non-metal buttons, don't need to be removed. If the scan isn't of the head, there's no need to remove metal braces or anything else from the mouth.
This answer is for general information. Your own case needs an examination by an orthodontist.