Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography

Toshihiro Sera, Hideki Fujioka, Hideo Yokota, Akitake Makinouchi, Ryutaro Himeno, Robert C. Schroter, Kazuo Tanishita

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Airway compliance is a key factor in understanding lung mechanics and is used as a clinical diagnostic index. Understanding such mechanics in small airways physiologically and clinically is critical. We have determined the "morphometric change" and "localized compliance" of small airways under "near"-physiological conditions; namely, the airways were embedded in parenchyma without dehydration and fixation. Previously, we developed a two-step method to visualize small airways in detail by staining the lung tissue with a radiopaque solution and then visualizing the tissue with a cone-beam microfocal X-ray computed tomography system (Sera et al. J Biomech 36: 1587-1594, 2003). In this study, we used this technique to analyze changes in diameter and length of the same small airways (∼150 μm ID) and then evaluated the localized compliance as a function of airway generation (Z). For smaller (<300-μm-diameter) airways, diameter was 36% larger at end-tidal inspiration and 89% larger at total lung capacity; length was 18% larger at end-tidal inspiration and 43% larger at total lung capacity than at functional residual capacity. Diameter, especially at smaller airways, did not behave linearly with V1/3 (where V is volume). With increasing lung pressure, diameter changed dramatically at a particular pressure and length changed approximately linearly during inflation and deflation. Percentage of airway volume for smaller airways did not behave linearly with that of lung volume. Smaller airways were generally more compliant than larger airways with increasing Z and exhibited hysteresis in their diameter behavior. Airways at higher Z deformed at a lower pressure than those at lower Z. These results indicated that smaller airways did not behave homogeneously.

Original languageEnglish
Pages (from-to)1665-1673
Number of pages9
JournalJournal of Applied Physiology
Volume96
Issue number5
DOIs
Publication statusPublished - 2004 May
Externally publishedYes

Fingerprint

X Ray Computed Tomography
Compliance
Total Lung Capacity
Lung
Mechanics
Pressure
Functional Residual Capacity
Economic Inflation
Dehydration
Staining and Labeling

Keywords

  • Morphometry change
  • Soft tissue
  • Surface tension
  • Tissue elasticity

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Sera, T., Fujioka, H., Yokota, H., Makinouchi, A., Himeno, R., Schroter, R. C., & Tanishita, K. (2004). Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography. Journal of Applied Physiology, 96(5), 1665-1673. https://doi.org/10.1152/japplphysiol.00624.2003

Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography. / Sera, Toshihiro; Fujioka, Hideki; Yokota, Hideo; Makinouchi, Akitake; Himeno, Ryutaro; Schroter, Robert C.; Tanishita, Kazuo.

In: Journal of Applied Physiology, Vol. 96, No. 5, 05.2004, p. 1665-1673.

Research output: Contribution to journalArticle

Sera, T, Fujioka, H, Yokota, H, Makinouchi, A, Himeno, R, Schroter, RC & Tanishita, K 2004, 'Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography', Journal of Applied Physiology, vol. 96, no. 5, pp. 1665-1673. https://doi.org/10.1152/japplphysiol.00624.2003
Sera, Toshihiro ; Fujioka, Hideki ; Yokota, Hideo ; Makinouchi, Akitake ; Himeno, Ryutaro ; Schroter, Robert C. ; Tanishita, Kazuo. / Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography. In: Journal of Applied Physiology. 2004 ; Vol. 96, No. 5. pp. 1665-1673.
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