As others have said you may benefit from a small dose of Diazapem, taken a little time before the scan. Your head will be inside the scanner, and many people find it tiresome. However, you will be able to hear the technicans speaking to you, and you will be able to speak to them. I should warn you though, the MRI makes a lot of banging noises - it is loud, but not continuously. You are give headphones to listen to music for some body areas being scanned, but, I am not sure if this happens for head scans. You will also have to sign a consent form when the procedure has been explained to you. If you are very claustrophobic, it might be an idea to ask the X Ray department if you can see the MR room, a few days before your scan is due. I am sure it will help you.
Good luck.