I am 23 years old and experienced precoious puberty. I remember going into my MRI, I was so scared! It broke while I was in it and I had to go to the bathroom so bad! and you know since it is an MRI they would not let me move, oh it was awful! But I amj sorrry that your daughter had what sounds like a much more tramatic experience. WEre you able to stay a the foot of the MRI to talk to her and such?
My parents opted to not put me on any hormone treatment. My height turned out to be only an inch or so than the presumed height, so I did not end up underhieght.
I do only know of my experience without treatment and I have turned out healthy. I hope that all turned out well on the MRI for you, and am very sorry that you are having a hard time with it. I am free to answer any questions that you may have about my experience

Hello!! I am also 23 and experienced Percocious puberty as a child..and dont worry, its scary now but your child will be all right! When I was little they put me on a GnRH analog, which after it was FDA approved was called Histrelin. I was part of a research protocol through University of Michigan medical center. The primary reason that they used that medication over others is that my bone age was accelerated as compared to my linear heighth, I lost 4yrs of growth. They knew that it prevented dwarfism, which it did because I am now 5'4". I was on it for 7yrs, and after I went off it I had regular periods. There seems to be no known side effects, I have PCOS, but my sister has that too and she was never on the medication so its not likely medically caused. The Histerlin was a daily shot, there were no immediate side effects to that either. Eventually I even became skilled enough to give it to myself. I work with children with special needs, and one of the little girls has percocious puberty as well. I believe that she is on Lupron and appears to have no side effects. Hers however was pharmacologically induced percocious puberty. She didnt grow when she was little so they put her on a growth hormone that worked too well...as far as the MRI, dont worry, I reccomend just finding out what medication they gave her and not giving it again. I had that happen to me once, they tried to put me under and instead it made me insanely hyper and talkative. Its sometimes a gamble...but it will be ok!