An MRI tech is a medical professional who takes photographs with an MRI scanner of a patient's organs and tissues. MRI, or magnetic resonance imaging, uses radio waves and magnetic fields to take photographs of the insides of a patient's body. Job Requirements : ARRT or ARDMS Certification - American Registry of Radiologic Technologists (ARRT) or the American Registry for Diagnostic Medical Sonography (ARDMS). Followed by 16 hours structured education activities. Only required to be licensed in New Hampshire, New Mexico, North Dakota, Oregon, Tennessee, and West Virginia.