title: Relationship between 3D behavior of the unilaterally paralyzed larynx and aerodynamic vocal function.
abstract: OBJECTIVE
  We used multi-slice helical computerized tomography (MSHCT) to evaluate the 3D characteristics of the laryngeal structures in patients with unilateral vocal fold paralysis (UVFP) during phonation, and compared the results with those obtained using an aerodynamic vocal function test.
  
  
  METHODS
  The subjects were 37 patients with UVFP. The region over the larynx was scanned during quiet phonation and again during inspiration using MSHCT, and 3D endoscopic and coronal reconstruction images were produced. Maximum phonation time (MPT) and mean airflow rate (MFR) during phonation were measured.
  
  
  RESULTS
  During phonation, the affected fold was thinner than the healthy fold in 30 subjects and located at a higher position than the healthy fold in 21 subjects. Abduction or thinning of the affected fold during phonation (paradoxical movement) was seen in seven subjects. MFR was significantly greater when the affected fold was thinner than the healthy fold during phonation, and MPT was significantly shorter when the affected fold showed paradoxical movement. Over-adduction of the healthy fold during phonation was present in 15 subjects. There were no significant differences in MPT or MFR between subjects with and without over-adduction.
  
  
  CONCLUSIONS
  The combination of MSHCT endoscopic and coronal reconstruction images enables the 3D characteristics of the unilaterally paralyzed larynx to be visualized during phonation, and some of these characteristics are significantly correlated with vocal function in patients with UVFP.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, School of Medicine, Kumamoto University, Kumamoto, Japan. yumoto@gpo.kumamoto-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Yumoto
authors.forename: Koji
authors.initials: K
authors.lastname: Nakano
authors.forename: Yukio
authors.initials: Y
authors.lastname: Oyamada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007818:Laryngeal Diseases / Q000175:diagnosis*; D007828:Laryngoscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D010699:Phonation / Q000502:physiology*; D011336:Probability; D011856:Radiographic Image Enhancement; D012016:Reference Values; D012119:Respiration; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D014741:Video Recording; D014826:Vocal Cord Paralysis / Q000175:diagnosis*; D014832:Voice Disorders / Q000503:physiopathology