A type of medical imaging used to visualise the inside of body cavities using an imaging device known as an endoscope. This consists of a video chip or a lens system on the end of a thin flexible or rigid tube and a light delivery system with an external source of light to illuminate the object or cavity being examined. The image from a fibreoptic lens system is viewed directly through the head piece of the endoscope. A video image can be viewed on an external monitor.

Endoscopes can vary greatly in length and can be inserted directly into accessible body cavities such as the upper airways (laryngoscopy, bronchoscopy) or the stomach (gastroscopy) or through surgical incisions into closed cavities such as the abdomen (laproscopy) or a joint (arthroscopy).