Cathode-ray tube


 * Reference for term: Ultrasonography - Goldberg, B. &amp; Pettersson, H.
 * Technical definition: Part of the ultrasonograph used for display of the returned signals, which produces a sharply focused beam of electrons that produces a bright spot on the phosphor-coated screen of the tube.
 * Reference for definition: Diagnostic Ultrasound: physical principles and exercices - Kremkau, W.F.
 * Comment: The fluorescent spot on the screen can be moved across or up and down the screen by applying voltages.