title: Computed tomography airway lumen volumetry in patients with acromegaly: Association with growth hormone levels and lung function.
abstract: BACKGROUND
  The segmentation and skeletonisation of images via computed tomography (CT) airway lumen volumetry provide a new perspective regarding the incorporation of this technique in medical practice. Our aim was to quantify morphological changes in the large airways of patients with acromegaly through CT and, secondarily, to correlate these findings with hormone levels and pulmonary function testing (PFT) parameters.
  
  
  METHODS
  This was a cross-sectional study in which 28 non-smoker patients with acromegaly and 15 control subjects underwent CT analysis of airway lumen volumetry with subsequent image segmentation and skeletonisation. Moreover, all participants were subjected to PFT.
  
  
  RESULTS
  Compared with the controls, patients with acromegaly presented higher diameters in the trachea, right main bronchus and left main bronchus. The patients with acromegaly also showed a higher tracheal sinuosity index (the deviation of a line from the shortest path, calculated by dividing total length by shortest possible path) than the controls [1.06 (1.02-1.09) vs. 1.03 (1.02-1.04), P = 0.04], and tracheal stenosis was observed in 25% of these individuals. The tracheal area was correlated with the levels of growth hormone (rs= 0.45, P = 0.02) and insulin-like growth factor type I (rs= 0.38, P = 0.04). The ratio between the forced expiratory flow and forced inspiratory flow at 50% of the forced vital capacity was correlated with the tracheal area (rs= 0.36, P = 0.02) and Δ tracheal diameters (rs= 0.58, P < 0.0001).
  
  
  CONCLUSIONS
  Patients with acromegaly exhibit tracheobronchomegaly and tracheal sinuosity/stenosis. Moreover, there are associations between the results of CT airway lumen volumetry, hormone levels and functional parameters of large airway obstruction.
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.|Faculty of Medical and Health Sciences of Juiz de Fora (SUPREMA), Teresinha de Jesus Hospital and Maternity, Juiz de Fora, Brazil.
authors.forename: Gustavo Bittencourt
authors.initials: GB
authors.lastname: Camilo
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|Laboratory of Pulmonary Engineering, Biomedical Engineering Program, Alberto Luiz Coimbra Institute of Post-Graduation and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Alysson Roncally Silva
authors.initials: ARS
authors.lastname: Carvalho
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|Laboratory of Pulmonary Engineering, Biomedical Engineering Program, Alberto Luiz Coimbra Institute of Post-Graduation and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Alan Ranieri Medeiros
authors.initials: ARM
authors.lastname: Guimarães
authors.affiliation: Neuroendocrinology Research Center/Endocrinology Section, Medical School and Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.|Neuroendocrine Unit, Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Leandro
authors.initials: L
authors.lastname: Kasuki
authors.affiliation: Neuroendocrinology Research Center/Endocrinology Section, Medical School and Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.|Neuroendocrine Unit, Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Mônica Roberto
authors.initials: MR
authors.lastname: Gadelha
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.|Department of Radiology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mogami
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.|Biomedical Instrumentation Laboratory, Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Rio de Janeiro, Brazil.|Postgraduate Program in Clinical and Experimental Physiopathology (FISCLINEX), School of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Pedro Lopes
authors.initials: PL
authors.lastname: de Melo
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.|Laboratory of Pulmonary Function, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Agnaldo José
authors.initials: AJ
authors.lastname: Lopes
mesh_terms: D000172:Acromegaly / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001980:Bronchi / Q000000981:diagnostic imaging* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014132:Trachea / Q000000981:diagnostic imaging* / Q000473:pathology*
chemical_list: D015415:Biomarkers; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone
keywords: acromegaly; airway obstruction; diagnostic imaging; respiratory function tests; tracheobronchomegaly