A river begins at a source (or more often several sources), follows a path called a course, and ends at a mouth or mouths. The water in a river is usually confined to a channel, made up of a stream bed between banks. In larger rivers there is often also a wider floodplain shaped by flood-waters over-topping the channel.
A 'computerized tomography' (CT) (or 'computerized axial tomography' (CAT) scan) uses a computer that takes data from several X-ray images of structures inside a human's or animal's body and converts them into pictures on a monitor.
CT scan (computerized axial tomography) A brain-scanning technique that uses a rotating, computerized X-ray tube to produce cross-sectional images of the structures of the brain; reveals the structures of the brain as well as abnormalities and injuries (tumors).