Asbestosis: high-resolution CT-pathologic correlation

Our plain-English summary of Asbestosis: high-resolution CT-pathologic correlation, by M. Akira, S. Yamamoto, K. Yokoyama, et al (Radiology, 1990).

The study

• Authors: M. Akira, S. Yamamoto, K. Yokoyama, N. Kita, K. Morinaga, T. Higashihara, T. Kozuka
• Journal: Radiology
• Published: 1990;176(2):389-94
• Cited by: 94 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 003831).

Abstract

High-resolution computed tomography (HRCT) was performed in seven inflated and fixed postmortem lungs from seven asbestos-exposed patients with pathologically proved asbestosis. The parenchymal abnormalities seen at in vitro HRCT included thickened intralobular lines (n = 7), thickened interlobular lines (n = 7), pleural-based opacities (n = 7), parenchymal fibrous bands (n = 5), subpleural curvilinear shadows (n = 4), ground-glass appearance (n = 4), traction bronchiectasis (n = 4), and honeycombing (n = 2). The thickened intralobular lines were shown histologically to be due to peribronchiolar fibrosis. Thickened interlobular lines were due mainly to interlobular fibrotic thickening in four lungs and edema in three. The peribronchiolar fibrosis was most severe in the subpleural lung regions, creating curvilinear line shadows and pleural-based areas of opacity. Some subpleural fibrosis extended proximally along the bronchovascular sheath to create bandlike lesions. Areas of ground-glass appearance on HRCT scans were shown to be the result of mild alveolar wall and interlobular septal thickening due to fibrosis or edema. Postmortem HRCT findings were similar to premortem HRCT findings and correlated well with the pathologic findings of asbestosis.

In plain English

Researchers at hospitals in Japan compared high-resolution CT (HRCT) scans of lungs removed at autopsy with the same tissue seen under the microscope. They examined seven lungs from seven people (five men, two women, aged 56 to 77 at death) with asbestosis confirmed by pathology. The group's asbestos exposure lasted 20.6 years on average. The article does not name the fiber types. All seven scanned lungs showed thickened lines within and between lobules (small lung units) and opacities along the pleura. Five showed fibrous bands, four showed curved lines under the pleura, four had a hazy ground-glass look, four had traction bronchiectasis (airways pulled wide by scarring), and two had honeycombing. Under the microscope, lines within lobules matched scarring around the smallest airways, and pleural-based opacities matched scarring just beneath the pleura. Lines between lobules matched mainly scarring in four lungs and fluid (edema) in the other three. Mild thickening of the alveolar walls could look normal on HRCT. The authors noted that events near death may have altered the findings. They concluded that HRCT findings correlated well with the pathology of asbestosis.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: radiologic-pathologic correlation study of postmortem lung specimens (HRCT of inflated, fixed lungs compared with matching histologic sections)
• Who was studied: Seven lungs (three right, four left) taken at autopsy from seven patients with asbestosis diagnosed by the Craighead histologic criteria: five men and two women, aged 56 to 77 at death (mean 67.6 years). Three had never smoked and four were smokers. The authors' institutions were in Osaka and Amagasaki, Japan. Dates of death were not given.
• Exposure: Asbestos exposure, with a mean duration of 20.6 years plus or minus 7.8 (range 10 to 34 years) and a mean interval from first exposure to death of 30.9 years. The three patients illustrated in the figures worked in the asbestos textile industry. Fiber types were not stated.
• Main results:
  • On HRCT of the seven lungs:
• thickened intralobular lines in 7
• thickened interlobular lines in 7
• pleural-based opacities in 7
• parenchymal fibrous bands in 5
• subpleural curvilinear shadows in 4
• ground-glass appearance in 4
• traction bronchiectasis in 4
• honeycombing in 2
  • Lesions were found mainly in the posterior lower zones of the lungs.
  • The subpleural dotlike lesions forming the thickened intralobular lines corresponded under the microscope to nodular fibrosis around the bronchioles, with later involvement of the alveolar ducts.
  • Pleural-based opacities corresponded under the microscope to subpleural pulmonary fibrosis.
  • Thickened interlobular lines corresponded mainly to fibrotic thickening in four lungs and to edematous thickening in the remaining three.
  • Ground-glass appearance (in four of seven lungs) corresponded to alveolar walls thickened by fibrosis or edema. Mild alveolar wall thickening with preserved lung architecture appeared as normal lung on HRCT.
• The authors' conclusion: The authors concluded that HRCT findings correlated well with the pathologic findings of asbestosis and that HRCT is useful for evaluating parenchymal changes in asbestosis.
• Limitations the authors state:
  • Events near death (agonal events) may have changed the pathologic findings. Interstitial edema in case 3 was attributed to such an event.
  • Subpleural pulmonary fibrosis could not easily be told apart from pleural thickening.
  • Areas of low attenuation suggesting emphysema and bullae were not evaluated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis.

Medical terms in this study, explained in our Lexicon: High-Resolution CT (HRCT), Subpleural Curvilinear Line, Honeycombing, Fibrosis.

Related studies

• Early asbestosis: evaluation with high-resolution CT — M. Akira, K. Yokoyama, et al. (1991)
• Asbestosis and other pulmonary fibrosis in asbestos-exposed workers: high-resolution CT features with pathological correlations — H. Arakawa, T. Kishimoto, et al. (2016)
• The comparison of high-resolution computed tomography findings in asbestosis and idiopathic pulmonary fibrosis — M. Akira, K. Morinaga (2016)
• High-resolution CT of benign asbestos-related diseases: clinical and radiographic correlation — D.R. Aberle, G. Gamsu, et al. (1988)
• Diagnosis of asbestosis by a time expanded wave form analysis, auscultation and high resolution computed tomography: a comparative study — N. al Jarad, B. Strickland, et al. (1993)
• Specificity of high-resolution CT findings in pulmonary asbestosis: do patients scanned for other indications have similar findings? — C.J. Bergin, R.A. Castellino, et al. (1994)

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