diagnostic procedure vs diagnostic technique

diagnostic procedure and diagnostic technique both are nouns.

Word	Noun	Adjective	Verb	Adverb
diagnostic procedure	Yes	No	No	No
diagnostic technique	Yes	No	No	No

As nouns, diagnostic procedure and diagnostic technique are synonyms defined as:

diagnostic procedure and diagnostic technique: a procedure followed in making a medical diagnosis

diagnostic procedure (noun)	diagnostic technique (noun)
a procedure followed in making a medical diagnosis	a procedure followed in making a medical diagnosis