center of gravity: the point around which the weight of the body is balanced
(usually in the lower pelvis or abdomen, depending upon body build).
cathode: the negative end of the X-ray tube; the source from which the
caudad: see "caudal."
caudal: refers to parts away from the head of the body.
central: refers to the mid area or main part of an organ.
central ray (CR): central or principal beam of rays emanating from the X-ray
central ray (CR) angle: the angle and direction of the central ray in relation to
the film or anatomical part.
cephalic: refers to parts that are toward the head of the body.
conefield: the area
of the beam
of radiation striking the film.
contrast (scale): a noticeable difference between adjacent radiographic
densities seen as varying shades of gray on the radiograph.
coronal plane: see "frontal plane."
cranial: see "cephalic."
decubitus position: position in which the patient is lying down.
demonstrate: to obtain a clear radiographic image of the primary and
surrounding anatomical structures that are of clinical interest.
distal: refers to parts farthest from the center, midline, or trunk; away from the
source or beginning.
dorsal: see "posterior."