Carol,
I am doing just that, training on the job in MRI at a hospital. I caught a lucky break, my radiography school offered a 6-week extension/internship in the modality of my choice and I chose MRI. My mentor then went on to hire me per diem. This is rare these days, as jobs are not so readily available. I am a per diem employee, which places me under the protection of the hopital's liability policy. Unless you are a student of a school that has an agreement with the clinical site where you train, or are an employee, you are not covered by any liability insurance to just come in and log clinical hours training. Where I live, there are community colleges that offer MRI training, and sometimes you have to find your own site that will agree to take you on to do your clinicals, and hospitals are the way to go because you see more complex studies in that type of setting. Good luck Carol, determination is the key to getting your foot in the door.
Patricia Roblin, R.T. (R)