Skip to main content
Thorax logoLink to Thorax
. 1990 Aug;45(8):602–605. doi: 10.1136/thx.45.8.602

Vertical gradients of lung density in supine subjects with fibrosing alveolitis or pulmonary emphysema.

A B Millar 1, D M Denison 1
PMCID: PMC462640  PMID: 2402722

Abstract

Computed tomography was used to determine the vertical gradient of density in the peripheral lung tissue of 12 patients with histologically proved fibrosing alveolitis and 12 patients with chronic bronchitis and evidence of pulmonary emphysema on the computed tomograms. Measurements were made at total lung capacity and at residual volume and compared with similar measurements from 12 normal subjects reported in a previous study. At residual volume the mean peripheral tissue density in the emphysematous lungs was 0.081 kg/l compared with 0.426 kg/l in the fibrotic lungs and 0.323 kg/l in the normal lungs. The observed densities in the three groups were compared with those in a theoretical model predicting the vertical changes of lung density caused by gravitational effects that would be found in lungs with differing compliance. The emphysematous lungs showed a much greater increase of density with descent down the lung than that predicted for normal lungs, and the results were explicable by an increase in compliance. The fibrotic lungs showed considerably less change in density than expected, implying loss of compliance. It is suggested that local changes of compliance are important determinants of vertical density gradients in diseased lungs.

Full text

PDF
602

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bergin C., Müller N., Nichols D. M., Lillington G., Hogg J. C., Mullen B., Grymaloski M. R., Osborne S., Paré P. D. The diagnosis of emphysema. A computed tomographic-pathologic correlation. Am Rev Respir Dis. 1986 Apr;133(4):541–546. doi: 10.1164/arrd.1986.133.4.541. [DOI] [PubMed] [Google Scholar]
  2. Coddington R., Mera S. L., Goddard P. R., Bradfield J. W. Pathological evaluation of computed tomography images of lungs. J Clin Pathol. 1982 May;35(5):536–540. doi: 10.1136/jcp.35.5.536. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Colebatch H. J., Finucane K. E., Smith M. M. Pulmonary conductance and elastic recoil relationships in asthma and emphysema. J Appl Physiol. 1973 Feb;34(2):143–153. doi: 10.1152/jappl.1973.34.2.143. [DOI] [PubMed] [Google Scholar]
  4. Denison D. M., Morgan M. D., Millar A. B. Estimation of regional gas and tissue volumes of the lung in supine man using computed tomography. Thorax. 1986 Aug;41(8):620–628. doi: 10.1136/thx.41.8.620. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fulmer J. D., Roberts W. C., von Gal E. R., Grystal R. G. Small airways in idiopathic pulmonary fibrosis. Comparison of morphologic and physiologic observations. J Clin Invest. 1977 Sep;60(3):595–610. doi: 10.1172/JCI108811. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Genereux G. P. Computed tomography and the lung: review of anatomic and densitometric features with their clinical application. J Can Assoc Radiol. 1985 Jun;36(2):88–102. [PubMed] [Google Scholar]
  7. Gibson G. J., Pride N. B. Pulmonary mechanics in fibrosing alveolitis: the effects of lung shrinkage. Am Rev Respir Dis. 1977 Oct;116(4):637–647. doi: 10.1164/arrd.1977.116.4.637. [DOI] [PubMed] [Google Scholar]
  8. Goddard P. R., Nicholson E. M., Laszlo G., Watt I. Computed tomography in pulmonary emphysema. Clin Radiol. 1982 Jul;33(4):379–387. doi: 10.1016/s0009-9260(82)80301-2. [DOI] [PubMed] [Google Scholar]
  9. Kreel L. Computer tomography of the thorax. Radiol Clin North Am. 1978 Dec;16(3):575–584. [PubMed] [Google Scholar]
  10. Meziane M. A., Hruban R. H., Zerhouni E. A., Wheeler P. S., Khouri N. F., Fishman E. K., Hutchins G. M., Siegelman S. S. High resolution CT of the lung parenchyma with pathologic correlation. Radiographics. 1988 Jan;8(1):27–54. doi: 10.1148/radiographics.8.1.3353534. [DOI] [PubMed] [Google Scholar]
  11. Millar A. B., Denison D. M. Vertical gradients of lung density in healthy supine men. Thorax. 1989 Jun;44(6):485–490. doi: 10.1136/thx.44.6.485. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Millar A. B., Fromson B., Strickland B. A., Denison D. M. Computed tomography based estimates of regional gas and tissue volume of the lung in supine subjects with chronic airflow limitation or fibrosing alveolitis. Thorax. 1986 Dec;41(12):932–939. doi: 10.1136/thx.41.12.932. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Rosenblum L. J., Mauceri R. A., Wellenstein D. E., Bassano D. A., Cohen W. N., Heitzman E. R. Computed tomography of the lung. Radiology. 1978 Nov;129(2):521–524. doi: 10.1148/129.2.521. [DOI] [PubMed] [Google Scholar]
  14. Solomon A., Kreel L., McNicol M., Johnson N. Computed tomography in pulmonary sarcoidosis. J Comput Assist Tomogr. 1979 Dec;3(6):754–758. [PubMed] [Google Scholar]
  15. Wilson T. A., Bachofen H. A model for mechanical structure of the alveolar duct. J Appl Physiol Respir Environ Exerc Physiol. 1982 Apr;52(4):1064–1070. doi: 10.1152/jappl.1982.52.4.1064. [DOI] [PubMed] [Google Scholar]

Articles from Thorax are provided here courtesy of BMJ Publishing Group

RESOURCES