Tracheal collapsibility in healthy volunteers during forced expiration: assessment with multidetector CT

Radiology. 2009 Jul;252(1):255-62. doi: 10.1148/radiol.2521081958. Epub 2009 May 6.


Purpose: To assess forced expiratory tracheal collapsibility in healthy volunteers by using multidetector computed tomography and to compare the results with the current diagnostic criterion for tracheomalacia.

Materials and methods: An institutional review board approved this HIPAA-compliant study. After informed consent was obtained, 51 healthy volunteers (age range, 25-75 years) with normal spirometry results and no history of smoking or risk factors for tracheomalacia were prospectively studied. Volunteers were imaged with a 64-detector row scanner, with spirometric monitoring at total lung capacity and during forced exhalation, with 40 mAs, 120 kVp, and 0.625-mm detector collimation. Cross-sectional area and sagittal and coronal diameters of the trachea were measured 1 cm above the aortic arch and 1 cm above the carina. The percentage of expiratory collapse, the reduction in sagittal and coronal diameters, and the number of participants exceeding the current diagnostic criterion (>50% expiratory reduction in cross-sectional area) for tracheomalacia were calculated.

Results: The final study population included 25 men and 26 women (mean age, 50 years). The mean percentage of expiratory reduction in tracheal lumen cross-sectional area was 54.34% +/- 18.6 (standard deviation) in the upper trachea and 56.14% +/- 19.3 in the lower trachea. Forty (78%) participants exceeded the current diagnostic criterion for tracheomalacia in the upper and/or lower trachea. Decreases in cross-sectional area of the upper and lower trachea correlated well with decreases in sagittal (r = 0.807 and 0.688, respectively) and coronal (r = 0.779 and 0.751, respectively) diameters (P < .001 for each correlation).

Conclusion: Healthy volunteers demonstrate a wide range of forced expiratory tracheal collapse, frequently exceeding the current diagnostic criterion for tracheomalacia.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Forced Expiratory Volume*
  • Humans
  • Male
  • Middle Aged
  • Reference Values
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*
  • Tracheomalacia / diagnostic imaging*
  • Tracheomalacia / physiopathology*