MRI is a very precise method of imaging human anatomy. Through the use of a strong magnetic field, radio signals, and a computer, an educated technologist is able to construct anatomic images. MRI procedures do not involve radiation. MRI can be done on numerous body parts. Some of the most common scans are done to evaluate nervous system and musculoskeletal disorders. These disorders can include multiple sclerosis, tumors, stroke, injury, and diseases affecting tendons, ligaments, and cartilage.