@AxlRose
Call up the MRI office and ask what kind of MRI machine it is first.
If it is a 1.5 Tesla machine, no need for concern even if you went with earplugs (but you must wear earplugs)
If it is a 3 Tesla machine, that's another story because they are significantly louder. Then you need to ask if the staff have their own earmuffs they supply and not just the headphones for music like they usually give; it is unlikely they will allow you to bring your own earmuffs because many contain metal or things the magnet will fall in love with. With a 3 Tesla machine in any case, you do need double protection.
Personally, I think you would be fine with well fitted earplugs and the headphones they give you. Then again, I was not safe when I only wore earplugs with a 3 T machine once, but my ears are extremely vulnerable to loud noises anyway as my inner ears are already inflamed and infected.
The other two times (actually 2.75, panicked and ran away the first 2 times) I had an MRI I was fine with good earplugs and wedged foam, but I have no idea if those were 3T or 1.5 T machines.
The point is that with earplugs, and even minimal secondary protection like foam blocks or headphones, you should be fine. Some MRI noises are also quieter than others. I would say with the protection in, the loudest they ever got for me was around 90 db for only about 3 minutes; that should not cause harm even for chronic T sufferers. Since they are only looking at your hand, I would also think the MRI would be over quickly.
Are there CT or other tests they can use to look at your torn ligament, or is the MRI the only way? If the MRI is the only road to follow, I think you need to go ahead and go because a torn ligament is a torn ligament.
One final note. Before you get the MRI, ask your doctor to prescribe a short course of
valium to take the night before and the day of your MRI to keep you in a blissful, heavenly land filled with puffy clouds. Your anxiety is more likely than the noise to produce a T spike, so you need to have that under your control to the best of your abilities when you get the MRI done.