Magnetic resonance imaging (MRI) is a medical imaging technique that uses a magnetic field and radio waves to generate detailed images of the body. MRIs are a non-invasive option to help your doctor gain insight into your health. An MRI can be used to diagnose and monitor a variety of conditions affecting the body including the brain, spinal cord, muscles, ligaments, and tendons. Because an MRI does not use radiation, it provides an ideal option for routine monitoring of conditions throughout the different stages of life including pregnancy.