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.
Computed Tomography (CT scanning) is a method of examining inside the body using X-rays, which create cross-sectional 2D or 3D images on a computer. It is possible to perform CT scans on any part of the body. They can show several kinds of body tissue (lung, bone, soft tissue and blood vessels) with great clarity and are able to diagnose diseases such as cancer, heart and vascular disease, injuries, brain tumours and musculoskeletal disorders.