Neuroradiology uses X-rays and other imaging procedures to learn about diseases of the nervous system. A neuroradiologist is a radiologist trained in diagnosing diseases of the nervous system using imaging systems such as X-rays, ultrasound, magnetic resonance imaging (MRI), computed tomography (also known as a CT or CAT scan) and angiography. These imaging systems are minimally or non-invasive. Other areas imaged and diagnosed by a neuroradiologist are the brain, head, neck and spinal cord.