title: Computed tomography appearance of normal nonossified thyroid cartilage: implication for tumor invasion diagnosis.
abstract: OBJECTIVE
  The objective of this study was to determine the density and homogeneity of the nonossified thyroid cartilage (NOTC) on contrast-enhanced computed tomography (CT) providing preliminary information for future evaluation of cartilage invasion using dual-energy CT.
  
  
  METHODS
  One hundred normal-larynx CT scans were evaluated for the density and homogeneity of NOTC.
  
  
  RESULTS
  The density of the NOTC was homogeneous in all cases. Nonossified thyroid cartilage had higher mean density than contiguous muscle, but there was overlap. In 47 cases, a lucent area was observed at the junction of the ossified and NOTC but not within the NOTC itself. In 11 cases, ossification was observed in only 1 cortex of the thyroid cartilage. Cartilage at the anterior commissure was not ossified in 7 cases.
  
  
  CONCLUSIONS
  Nonossified thyroid cartilage has a homogeneous appearance on contrast-enhanced CT scans, but showed some normal variations that could be mistakenly reported as tumor invasion.
authors.affiliation: From the Departments of *Radiology and †Otolaryngology, Massachusetts Eye and Ear Infirmary; and ‡Department of Otology and Laryngology, Harvard Medical School, Boston, MA; and §Department of Radiology, Jewish General Hospital and McGill University, Montreal, Quebec, Canada.
authors.forename: Nazanin
authors.initials: N
authors.lastname: Dadfar
authors.forename: Mohammad
authors.initials: M
authors.lastname: Seyyedi
authors.forename: Reza
authors.initials: R
authors.lastname: Forghani
authors.forename: Hugh D
authors.initials: HD
authors.lastname: Curtin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D013957:Thyroid Cartilage / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed