. . "Substances administered during imaging procedures that allows delineation of internal structures. Contrast agents appear opaque due to the difference in absorption of X-rays or other electromagnetic waves and surrounding tissue.NCI" . "Contrast Agent"^^ . "Contrast DrugsSYNCI" . . "Contrast AgentPTNCI" . . "CDISC"^^ . . "Contrast Agent"^^ . "Contrast MediumSYNCI" . "Contrast_Agent"^^ . . . "contrast materialPTNCI-GLOSSCDR0000409764" . "Contrast AgentPTNICHD" . "C0009924"^^ . "A dye or other substance that helps show abnormal areas inside the body. It is given by injection into a vein, by enema, or by mouth. Contrast material may be used with x-rays, CT scans, MRI, or other imaging tests.NCI-GLOSS" . . "Substances administered during diagnostic procedures that allows delineation of internal structures. Contrast agents appear opaque due to the difference in absorption of X-rays or other electromagnetic waves and surrounding tissue.CDISC" . "Contrast AgentPTCDISC" . "NICHD"^^ . "C390"^^ . . "Indicator, Reagent, or Diagnostic Aid"^^ . "Positive contrast agents have greater absorption and structures appear light. Negative contrast agents have a lesser degree of absorption and structures appear dark."^^ .