title: Normal thoracic radiographic appearance of the cynomolgus monkey (Macaca fascicularis).
abstract: BACKGROUND
  The cynomolgus monkey (Macaca fascicularis) has been increasingly used as a non-human primate model in biomedical research. As establishing baseline thoracic radiography for the cynomolgus monkey is essential, we tested the hypothesis that age and sex may affect the thoracic radiography parameters of this species.
  
  
  METHODS
  Here, 697 healthy cynomolgus monkeys were segregated by sex and age (three age groups: 25-36 months, 37-48 months, 49-60 months). The lung length (LL), maximal interior thoracic depth (TD), maximal interior thoracic breadth (TBr), cardiac silhouette breadth (CBr), cardiothoracic ratio (CR), right and left costophrenic angles (RCA and LCA), and right hilar height ratio (R-HHR) were assessed by chest film. Statistical analysis was applied to examine the effect of age, sex, and age × sex interactions.
  
  
  RESULTS
  Significant effects by age were shown for LL, TD, TBr, CBr, and CR. Significant effects by sex were found for TD, TBr, CBr, CR, and R-HHR. Significant effects by age × sex were observed for TD, TBr, CBr, and CR. Both TD and TBr increased with age in both sexes, and both were significantly higher in males than in females in the group aged 49-60 months. CBr increased with age and was significantly higher in males than in females across all age groups. CR declined with age and was significantly higher in males than females across all age groups, and CR was similar or slightly higher relative to those previously found in other non-human primate species. As to the other parameters with no significant sex nor age-related differences, the R-HHR was greater than 1.00, and the angulation of bilateral costophrenic angles were sharp.
  
  
  CONCLUSIONS
  The thoracic radiographic parameters for the healthy cynomolgus monkey presented here should prove useful in veterinary practice, research involving non-human primate models of respiratory or cardiovascular disorders, and morphological studies on cynomolgus monkeys.
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China ; Institute of Neuroscience, Chongqing Medical University, Chongqing, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xie
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China ; Institute of Neuroscience, Chongqing Medical University, Chongqing, China.
authors.forename: Qinming
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Suzhou Xishan Zhongke Laboratory Animal Co., Ltd., Suzhou, China.
authors.forename: Shigang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China ; Institute of Neuroscience, Chongqing Medical University, Chongqing, China.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China ; Institute of Neuroscience, Chongqing Medical University, Chongqing, China.
authors.forename: Yongjia
authors.initials: Y
authors.lastname: Ji
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Lujun
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Xu
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gong
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Narayan D
authors.initials: ND
authors.lastname: Melgiri
authors.affiliation: Department of Neurology, The First Affiliated Hospital at Chongqing Medical University, Chongqing, China ; Chongqing Key Laboratory of Neurobiology, Chongqing, China ; Institute of Neuroscience, Chongqing Medical University, Chongqing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xie
mesh_terms: D000367:Age Factors; D000818:Animals; D005260:Female; D008168:Lung / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008252:Macaca fascicularis / Q000033:anatomy & histology; D008297:Male; D009929:Organ Size; D013902:Radiography, Thoracic / Q000592:standards*; D012016:Reference Values; D012737:Sex Factors; D013909:Thorax / Q000033:anatomy & histology