pyelogram vs radiograph

pyelogram

noun
  • An image produced by means of pyelography. 

radiograph

noun
  • An image, often a photographic negative, produced by radiation other than normal light; especially an X-ray photograph. 

  • An instrument for measuring and recording solar radiation. 

verb
  • To produce a radiograph image. 

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