encephalogram vs X-ray picture

encephalogram and X-ray picture both are nouns.

Word	Noun	Adjective	Verb	Adverb
encephalogram	Yes	No	No	No
X-ray picture	Yes	No	No	No

As nouns, X-ray picture is a hypernym of encephalogram; that is, X-ray picture is a word with a broader meaning than encephalogram:

encephalogram: an X ray of the brain made by replacing spinal fluid with a gas (usually oxygen) to improve contrast
X-ray picture: a radiogram made by exposing photographic film to X rays; used in medical diagnosis

Other hypernyms of encephalogram include roentgenogram, X-ray, X-ray photograph, X ray.

encephalogram (noun)	X-ray picture (noun)
an X ray of the brain made by replacing spinal fluid with a gas (usually oxygen) to improve contrast	a radiogram made by exposing photographic film to X rays; used in medical diagnosis
a graphical record of electrical activity of the brain; produced by an electroencephalograph