I had an open MRI and the doctors who have seen it said it was one of the clearest MRI films they have seen. I had no incentive to get a "real" MRI after that. Give it a try if they offer it in your area.
My chiro told a funny story of a man who barely fit in the MRI tube and had a panic attack once he got in the tube, yelling and screaming and basically making the situation a lot worse as he tensed up. The technician couldn't get him out of the tube and called the chiro asking for permission to sedate the guy to get him to relax enough to be able to slide him out. The tech was mad because he didn't want the guy breaking his equipment. The chiro of course wasn't authorized to prescribe medicine, but when he heard the patient screaming in the background he told the technician that if he were him, he'd sedate him anyway - which is what the tech ended up doing. The chiro thought the whole situation was terribly funny, though I don't think the patient nor the tech shared the humor.
Ditto to what the others have said. The weight limit is more a "generalized" limit more geared toward size then the weight. The supine (closed tube) MRI's can only accommodate persons to a certain size.
But you can get an open MRI and ibake&pray is correct, most often, the scan is not as crisp as with the closed MRI.
My spine surgeon that just ordered my MRI stated that this was to be a closed MRI to get the best possible detail/clarity.
Hope this helps. Take care. Tammy
"believe in the beauty of your dreams"- E. Roosevelt
L5/S1 bulging @ 18, now 46; still there (but no pain)
Fusion at L4/L5 Apr -2006
Solidly Fused Nov-2006
A Success, but still improving!