lymphangiogram vs radiogram

lymphangiogram

noun
  • A diagnostic image produced by lymphangiography. 

radiogram

noun
  • A radiograph 

  • An entertainment device that combined a radio and a record player or gramophone. 

  • A message, like a telegram, transmitted by radio rather than wires. 

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