Yes, you can have an MRI after you've had hardware put in. I had an ACDF 3 years ago, and they did an MRI without contract on my lower back, and the MRI with contrast on my cervical spine .....they said the contrast allowed them to see better where the previous surgery and hardware was..
I had PLIF with hardware in April, 2006. Yes, I had an MRI a couple of months ago to check on fusing process, no problems at all. I asked the tech before they took me back to do it. I said are those magnets in the MRI gonna suck my rods and screws out? She laughed, said lots of people ask that, no problem. So relax. Bren
I have hardware that is very old and it does interfere with the quality of ct and mri scans. They used surgical steel rather than titanium then. The newer titanium hardware does not interfere as much. My ct scan done two years ago proved too difficult to read because of artifacting. As far as the mri with contrast I had one done last year without any problems.