2012 Radiology Exam - CT/MRI Case 1


  • 8-year-old, male castrated American Paint Horse
  • Purulent discharge from left nostril


  • Transverse and sagittal images of the skull


  • Soft-tissue attenuating material mixed with gas filling all left paranasal sinus cavities and a portion of the left caudal nasal cavity
  • Gas in pulp cavity and infundibulum of the left first maxillary molar (209) and the left second maxillary molar (210)
  • Expansion or widening of the apical periodontal space surrounding left maxillary molar 1 (209)
  • Faint disruption of alveolar bone surrounding 209
  • Mild widening of periodontal space surrounding left maxillary second molar (210)
  • Little or no lysis of the facial bones or turbinates


  • Tooth root abscess (or periapical disease) of left first maxillary molar (209)
  • Possible tooth root abscess of left second maxillary molar (210)
  • Left paranasal sinusitis secondary to tooth root abscess

Case Management

  • Recommend surgical repulsion of 209 with sinus lavage. (Full points were given if clear recommendation for surgical opening of sinuses and repulsion of this tooth alone.)
  • Evaluate 210 for repulsion at time of surgery. (No points deducted if not recommended.)

All candidates identified the material in the left paranasal sinuses. Most candidates identified the gas within the teeth, though some commented that this was an incidental finding and did not scrutinize these teeth more closely. Successful candidates identified the expansion of the periodontal space surrounding the 209 with a slightly smaller number identifying the disruption of the alveolar bone and the mild expansion of the periodontal space surrounding 210. Unsuccessful candidates failed to identify the periodontal and alveolar bone lesions or failed to realize their significance.