title: Dual-energy subtraction radiography improves laryngeal delineation in patients with moderate to severe cervical spondylosis.
abstract: OBJECTIVE
  To investigate the feasibility of dual-energy subtraction (DES) in patients with moderate-severe cervical spondylosis for improving delineation of the larynx on flat panel detector (FPD) radiography.
  
  
  METHODS
  For 118 patients, we graded conventional/DES anterior-posterior views for delineation of the vocal cords, subglottis, and pyriform sinus using a 5-point scale and lateral views from conventional laryngeal FPD radiography to determine cervical spondylosis severity on a scale from 0 (none) to 3 (severe). We compared the delineation of each anatomical structure in both groups of grades 0-1 and grades 2-3 of spondylosis severity between conventional and DES methods and the improved delineation rate for each anatomical structure by DES compared to the conventional method between both groups.
  
  
  RESULTS
  With DES, the delineation of each anatomical structure was significantly better than with conventional radiography for both groups (P < 0.0001). The improved delineation rate of the vocal cord and subglottis using DES was significantly higher in grades 2-3 than in grades 0-1 (P < 0.05), although there was no significant difference in the delineation rate of the pyriform sinus between the groups (P = 0.847).
  
  
  CONCLUSIONS
  DES provides better delineation of the laryngeal anatomy than conventional FPD radiography predominantly in patients with moderate-severe cervical spondylosis.
authors.affiliation: Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa, Tokyo, 116-8567, Japan. machira@dnh.twmu.ac.jp
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Machida
authors.forename: Keiko
authors.initials: K
authors.lastname: Yoda
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Arai
authors.forename: Suguru
authors.initials: S
authors.lastname: Nishida
authors.forename: Masayasu
authors.initials: M
authors.lastname: Asanuma
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yuhara
authors.forename: Takako
authors.initials: T
authors.lastname: Mori
authors.forename: Mieko
authors.initials: M
authors.lastname: Tamura
authors.forename: Eiko
authors.initials: E
authors.lastname: Ueno
authors.forename: John M
authors.initials: JM
authors.lastname: Sabol
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007830:Larynx / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D055009:Spondylosis / Q000000981:diagnostic imaging*; D013382:Subtraction Technique; D014963:X-Ray Intensifying Screens