title: Collateral Ventilation Quantification Using Xenon-Enhanced Dynamic Dual-Energy CT: Differences between Canine and Swine Models of Bronchial Occlusion.
abstract: OBJECTIVE
  The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT.
  
  
  METHODS
  Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model.
  
  
  RESULTS
  A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 ± 5.0 Hounsfield units [HU] vs. -2.8 ± 7.1 HU, p = 0.001; normalized percentage difference, -79.8 ± 1.8% vs. -5.4 ± 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892).
  
  
  CONCLUSIONS
  Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea.
authors.forename: Eun-Ah
authors.initials: EA
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea.
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
authors.affiliation: Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea.
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea.
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Park
mesh_terms: D000402:Airway Obstruction / Q000000981:diagnostic imaging*; D000818:Animals; D001982:Bronchial Diseases / Q000000981:diagnostic imaging*; D001995:Bronchography / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D012123:Pulmonary Ventilation / Q000502:physiology*; D012119:Respiration; D013552:Swine; D036542:Tomography, Spiral Computed / Q000379:methods*; D014978:Xenon
chemical_list: D014978:Xenon
keywords: Chronic obstructive pulmonary disease; Collateral ventilation; Dual-energy CT; Emphysema; Xenon