angiogram vs angiography

angiogram

noun
  • An X-ray image of the blood vessels gained after the injection of a radiopaque contrast medium. 

angiography

noun
  • A medical imaging technique in which an X-ray image is taken to visualize the inside of blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers. 

How often have the words angiogram and angiography occurred in a corpus of books? (source: Google Ngram Viewer )