title: Imaging characteristics of ameloblastomas and diagnostic value of computed tomography and magnetic resonance imaging in a series of 26 patients.
abstract: OBJECTIVE
  To evaluate the imaging characteristics of ameloblastomas and to analyze the diagnostic value of computed tomography (CT) and magnetic resonance imaging (MRI) compared with conventional dentoalveolar imaging.
  
  
  METHODS
  In this observational retrospective study, the panoramic radiographs (n = 25) and the CT (n = 26) and MRI (n = 5) images of histopathologically verified ameloblastomas in 26 patients were reviewed.
  
  
  RESULTS
  Characteristic findings were multilocularity, marked expansion of the cortical plate, perforation at an earlier stage, and extensive root resorption. On contrast-enhanced CT or MRI, the majority (14 of 17) of the nonunicystic ameloblastomas contained a mixed cystic and solid pattern. Unicystic ameloblastomas (n = 6) and ameloblastomas derived from the cyst epithelium (n = 2) showed thick rim enhancement or a mural solid component in an otherwise cystic lesion.
  
  
  CONCLUSIONS
  Contrast-enhanced CT and MRI greatly aid in distinguishing between ameloblastomas and other cystlike lesions because they allow for visualization of the mixed cystic and solid content characteristic of nonunicystic ameloblastomas. The differential diagnostic value of CT and MRI is significant with regard to unicystic ameloblastomas.
authors.affiliation: HUS Medical Imaging Center, Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland. Electronic address: Satu.apajalahti@hus.fi.
authors.forename: Satu
authors.initials: S
authors.lastname: Apajalahti
authors.affiliation: Department of Oral Pathology, University of Helsinki, Helsinki, Finland.
authors.forename: Jetta
authors.initials: J
authors.lastname: Kelppe
authors.affiliation: Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Kontio
authors.affiliation: Department of Pathology/Haartman Institute and HUSLab, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Hagström
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000564:Ameloblastoma / Q000175:diagnosis*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007573:Jaw Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA