No. Mri (magnetic resonance imaging) uses magnetic fields rather than radiation. That is one of the benefits of using MRI instead of ct ("cat scans") or x rays. As far as we know, exposure to this level of magnetic energy is not harmful. If you have a pacemaker, cochlear implant, implanted nerve stimulator, or other metal in your body, you may not be able to have an mri.
Here is an example of an MRI questionnaire: http://www.Mrisafety.Com/screening_form/prescrnf.Pdf.
No. Mri does not use ionizing radiation. There are other safety concerns and before your scan you will be asked a series of questions to be sure the MRI is safe for you.