WordNet (r) 3.0 (2006):

radiogram
    n 1: a message transmitted by wireless telegraphy
    2: a photographic image produced on a radiosensitive surface by
       radiation other than visible light (especially by X-rays or
       gamma rays) [syn: radiogram, radiograph, shadowgraph,
       skiagraph, skiagram]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "radiogram":
   ECG, EEG, EKG, X ray, X-ray movie, cable, cablegram, chest X-ray,
   day letter, electrocardiogram, electrocorticogram,
   electroencephalogram, electroencephalograph, electromyogram,
   encephalogram, encephalograph, fast telegram, night letter,
   orthodiagram, photofluorogram, photofluorograph, photogram,
   pyelogram, radiograph, roentgenogram, roentgenograph, scotograph,
   shadowgram, shadowgraph, skiagram, skiagraph, telegram, telegraph,
   telex, wire