WordNet (r) 3.0 (2006):

radiology
    n 1: the branch of medical science dealing with the medical use
         of X-rays or other penetrating radiation
    2: (radiology) examination of the inner structure of opaque
       objects using X rays or other penetrating radiation [syn:
       radioscopy, radiology]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "radiology":
   X-ray photometry, X-ray spectrometry, atom-tagging, atomic science,
   atomics, atomistics, atomology, curiescopy, fluoroscopy,
   mass spectrography, mass spectrometry, molecular physics,
   nuclear chemistry, nuclear physics, orthodiagraphy,
   photofluorography, quantum mechanics, radiation physics,
   radiobiology, radiochemistry, radiography, radiological physics,
   radiometallography, radiometry, radiopathology, radioscopy,
   radiotechnology, radiotherapy, roentgenography, roentgenology,
   roentgenoscopy, spectroradiometry, thermionics,
   tracer investigation, wave mechanics