CAT scan vs scan

CAT scan and scan both are nouns.

Word	Noun	Adjective	Verb	Adverb
CAT scan	Yes	No	No	No
scan	Yes	No	Yes	No

As nouns, CAT scan and scan are synonyms defined as:

CAT scan (noun)	scan (noun)
an image produced by scanning	the act of scanning; systematic examination of a prescribed region
	an image produced by scanning

CAT scan (verb)	scan (verb)
	obtain data from magnetic tapes or other digital sources
	read metrically
	make a wide, sweeping search of
	move a light beam over; in electronics, to reproduce an image
	examine hastily
	examine minutely or intensely
	conform to a metrical pattern