Meaning of CONTRAST MEDIUM

WordNet Dictionary
	Definition:		[n]  a substance that is opaque to x-rays; when administered it allows a radiologist to examine the organ or tissue it fills
	Synonyms:		contrast material
	See Also:		medium
Medical Dictionary
	Definition:		A substance, opaque to xrays or other electromagnetic waves, introduced into the body for the purpose of delineating internal anatomy for diagnostic purposes.