Hi,
Im no doctor either so I will just tell you what i was told. I think it will depend what 'problem' you have with your neck. Your neck is indeed scanned by ultrasound during the medical but when i asked what its for, they said its to check the Carotid Artery. This makes sense as they only ultrasound the right side of your neck and that is where this Artery runs......at least thats what Wikepedia told me when i looked it up
Regarding the MRI.....again this is just what i was told but apparently that is to check your brain for potential tumours etc so not sure if it has anything to do with the neck. Again that was just what i was told when i asked.
Obviously we dont know what your problem is but i would say go for it anyway. The medical is very 'particular' compared to what we are used to here in Europe but you may find they dont even pick up on your 'issue' and you sail through.
Good luck with whatever you choose.
All the best