- a not transparent to X-rays or other forms of radiation
barium sulfate is radiopaque
- Injections of radiopaque dye also help X rays to show whether arteries have been displaced or damaged enough to deprive part of the brain of its blood supply.
- To guard against clots, he flushed out the whole artery-vein system with a special saline solution combined with antibiotics, an anticoagulant and a radiopaque dye.
- Arteriograms (Xray still photos of arteries that have been flooded with radiopaque dye) help, but they are not always reliable: the "flooding" technique often fails to fill the .