The "gamuts.net" web site lets you navigate the Radiology Gamuts Ontology (RGO), a knowledge resource for radiology diagnosis. RGO hosts more than 2,000 differential-diagnosis listings for imaging findings in all body systems. You can view all of the causes of an finding, then click on one of the diagnoses to view all of the findings that it causes. Each page is illustrated with relevant images from peer-reviewed journals that are retrieved on demand from the ARRS GoldMiner® image search engine.


  • 16,912 entities
    • 12,878 "causes" (conditions that cause findings)
    • 4,662 "effects" (e.g., imaging findings)

  • 1,782 hierarchical ("is-a") links
  • 55,564 causal ("may-cause") links


Charles E. Kahn, Jr., MD, MS
Dhiraj Baruah, MD
Joseph J. Budovec, MD
Stephen W. Goth, MD
Cesar A. Lam, MD
Kaushik Shahir, MD
Matthew W. Shore, MD


  1. Budovec JJ, Lam CA, Kahn CE Jr. Radiology Gamuts Ontology: differential diagnosis for the Semantic Web. RadioGraphics 2014; 31:254-264.
  2. Kahn CE Jr. Ontology-based diagnostic decision support in radiology. Studies in Health Technology and Informatics 2014; 205:78-82.
  3. Kahn CE Jr. Integrating ontologies of rare diseases and radiological diagnosis. Journal of the American Medical Informatics Association 2015; 22:1164-1168.
  4. Kahn CE Jr. Transitive closure of subsumption and causal relations in a large ontology of radiological diagnosis. Journal of Biomedical Informatics 2016; 61:27-33.
  5. Kahn CE Jr. An ontology-based approach to estimate the frequency of rare diseases in narrative-text radiology reports. Studies in Health Technology and Informatics 2017; 896-900.


  • Maurice M. Reeder (editor), with William G. Bradley, Jr. and Christopher R. Merritt. Gamuts in Radiology 4.0 Web Version: Comprehensive Lists of Imaging Differential Diagnoses 2003.
  • Hooshang Taybi and Ralph S. Lachman. Radiology of Syndromes, Metabolic Disorders, and Skeletal Dysplasias, 4th ed. 1996.
  • Wolfgang Dähnert. Radiology Review Manual, 7th ed., revised 2011.
  • Maurice M. Reeder (editor), with William G. Bradley, Jr. and Christopher R. Merritt. Reeder and Felson's Gamuts in Radiology: Comprehensive Lists of Roentgen Differential Diagnosis, 4th ed. 2003.
  • Ralph S. Lachman. Taybi and Lachman's Radiology of Syndromes, Metabolic Disorders and Skeletal Dysplasias, 5e 2006.