What health issue led you to having an MRI scan?

Usually a MRI scan is order when all other possible reasons fail to uncover the actual problem.
Fibroids for me years ago, quite common.

I was having my hearing checked, and the audiologist noticed a decoding issue, where I hear a sound but misunderstand the actual word. Because it was only on one ear, he suggested I get checked for an undiagnosed brain injury. So I had an MRI. Doctors didn’t find anything abnormal.

I had MRSA in my lungs and spine.

Kidney stone. They were pretty sure what it was, but wanted a look at what it was like, IIRC.

Husband had one to diagnose epilepsy.

My kidney stones x-ray (or sonar) revealed another thing in one of my kidneys, so an MRI was ordered.
A cyste was found.

I had a “clicking” in my knee and problems walking without a limp. Torn meniscus. No real injury I can remember. Also, sharp, shooting pain in my shoulder that severely limited motion and strength. Bone spur digging into a tendon.

A friend of mine had one to find her breast cancer. Didn’t show on the mammogram. Possibly, she had an ultrasound too, I’m not sure if they saw something on that. Luckily, she was under military care and getting an MRI isn’t looked at as too expensive. The machine is there, the tech is salaried, just pay for a little electricity to run the thing. I wonder if she had been in private care if the MRI would have been done.

I had an MRI when I had vertigo from an accident (total waste of funds and time and I’m still annoyed about it). You said not for an accident though, and that was an accident. I had one many years ago for something else, but I’m not sure what. I think it was a back injury.

First one diagnosed a knee injury that physical therapy was not resolving. Found a cyst that required a scope.
The second was to confirm that my loss of smell was related to a bad sinus infection and not brain cancer. Thankfully a normal scan.

To map my heart’s left atrium prior to having a radio frequency catheter ablation.

@zenvelo Maybe certain tones only one can’t hear. I discovered in one ear one particular tone ,that I cannot hear due to late mother dropping a teaspoonful of too hot drops in that one ear.
( I had an ear infection and was supposed to have liquid medicine given by mouth, not directly in my ear! ) This was done in 1948/49 when I was a small child.
My ear was irreversibly damaged..but thank God not too noticeable and I have the other ear not affected so I managed well.