[Chocaholic]

Older scanners had a 60cm bore and could be quite claustrophobic...and loud. Still many of those in use, but...no thanks. Newer units are considerably larger (73cm as I recall) and have innovative technologies to prevent claustrophobia. Gradients housed in a vacuum is used by one company to significantly reduce noise, and as a result, it's the device you'll often see in military/VA's (due to PTSD). Also, new systems may incorporate video systems so you can lay there and watch a video/movie while being scanned, or listen to music. There's one company (maybe more) that makes an open-MRI which is common to see in outpatient centers. Easier on the patient but the image quality isn't as good.

Often you will still be injected with Gadolinium as a contrast agent which can be uncomfortable and isn't very healthy as it's a heavy metal that builds up in your system. Do a search if interested. The tech has come a long way but isn't perfect. At least there's no radiation.