Advantage MRI has 6 premier centers in the Chigago Illinois market. Magnetic Resonance Imaging, or MRI, is the primary diagnostic tool for many physicians today. MRI uses radio waves and magnetic fields to create images of your anatomy without the use of radiation present in x-rays and CT scanning. The procedure is painless and has no discomfort or side effects. MRI exams typically last between thirty and sixty minutes depending upon the information requested by your physician. Your only requirement is to lie as still as possible.