MRI Scan Magnetic Resonance Imaging (MRI) is a diagnostic scanning technique based on the principles of magnetic resonance. MRI uses a strong magnetic field and radio frequency waves to produce detailed images of the internal organs and tissues. It can be used to investigate almost any part of the body and is most commonly used to examine the brain, joints and discs in the spine. No radiation is involved in an MRI scan. Ultrasound Ultrasound imaging (or sonography) is a method of acquiring information about the inside of the body using high frequency sound waves to show the size, shape and texture of the internal organs and blood vessels. Ultrasound waves cannot pass through gas so the stomach or bowel cannot be evaluated. CT Scan Computed Tomography (CT) is a scanning technique that uses X-Rays to take highly detailed images of the body. A CT scan can give detailed information about many parts of the body, including the lungs, bones, soft tissues, heart and blood vessels. It can be used to diagnose and monitor many conditions.