Radiopaque

Radiopaque: Opaque to one or another form of radiation such as X-irradiation (X-rays). Radiopaque objects are not pervious to radiation, instead, they block it. Metal, for instance, is radiopaque. If a child swallows a metal paperclip, the paperclip may be visible on X-ray and appear as a white object (in the form of a paperclip) within the child's intestine. Dyes that are radiopaque are used in radiology to enhance anatomic structure. An intravenous pyelogram (better known as an IVP) is an X-ray study of the kidneys that highlights the renal pelvis where the urine is collected and the ureters that serve as conduits for the urine from the kidneys to the bladder. The word "radiopaque" comes from "radio" plus "opaque" minus an "o." The opposite of radiopaque is radiolucent.