decubitus projection

de·cu·bi·tus pro·jec·tion

(dē-kyū'bi-tŭs prŏ-jek'shŭn)
radiology Procedure in which a patient to be x-rayed is placed in a decubitus position, with the x-ray beam directed horizontally.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

decubitus projection

A radiographic procedure, using the decubitus positions and the central ray of the x-ray beam placed horizontally, which aids in the demonstration of air-fluid levels.
Medical Dictionary, © 2009 Farlex and Partners