Sarah Constantine MBBS, FRANZC, Presenter: Nothing to Disclose

Each image has a focal plane where the structures are sharply projected, and outside this area the structures appear blurred. Double images are seen when an object or anatomical structure is between the x-ray tube and the film twice. Ghost images occur when an object or anatomic structure that is outside the focal plane, and is dense enough to attenuate the x-ray beam and project an image.  

The orthopantomogram (OPG) is a commonly requested examination, referred by both medical practitioners and dentists. Despite its frequency in practice, there is a reluctance by many radiologists to provide a detailed radiological report, due to a lack of familiarity with the normal anatomy and artefacts seen on the OPG. This presentation demonstrates the normal anatomy seen on the OPG, as well as artefacts produced by the tomographic technique, and incorrect patient positioning. • Double images • Ghost images • Normal anatomy • Calcifications • Positioning errors – chin too low, chin too high, head too far forward, head too far back, head rotation, patient movement • False pathology    

http://abstract.rsna.org/uploads/2014/14015495/14015495_ixkp.pdf

Constantine, S, The A to Z of OPGs.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015495.html