I'm getting a free MRI done because of a study protocol, what does that mean?

I have some kind of congenital heart defect, something I was born with, which the doctors don't know what it's all about. I have been told I have a small hole in my heart, a systolic/diastolic murmur level number 4, and a left to right shunt, where blood is flowing from the right atrium to the aorta, or something like that. Anyways, they're not quite sure what it is, so I have to get an MRI done, and since it's a pre-existing condition, I can't get insurance or anything, but I was told recently that I might possibly be getting the MRI done for free through a study protocol. What exactly does that mean? I think it's where it's like a research study and they're probably going to use my mri results for teaching and learning, but I'm not quite sure? Thanks in advance.