Brain imaging refers to methods for taking pictures of the living brain. These methods are non-invasive, meaning that there is no need for surgery or other procedures that involve entering the body.

Many forms of brain imaging involve use of x-rays, which pass through the body and form an image on a photographic plate. Computed tomography (CT or CAT) is one such method. Magnetic resonance imaging (MRI) is a related method which uses magnetic and radiofrequency energy instead of x-rays. Both CT and MRI can provide high-resolution pictures of the brain, helpful in detecting abnormalities such as tumors or aneurysms. CT has higher spatial resolution than MRI, but MRI has better contrast, and so each technique is useful under different conditions.