Computed tomography in the diagnosis of asbestos-related thoracic disease

Our plain-English summary of Computed tomography in the diagnosis of asbestos-related thoracic disease, by G. Gamsu, D.R. Aberle, D. Lynch (Journal of Thoracic Imaging, 1989).

The study

• Authors: G. Gamsu, D.R. Aberle, D. Lynch
• Journal: Journal of Thoracic Imaging
• Published: 1989;4(1):61-7
• Type of article: Review
• Cited by: 34 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. 002547).

Abstract

High-resolution computed tomography (HRCT) has improved the radiologist's ability to detect and potentially quantify the abnormalities of asbestos exposure. It has proved to be more sensitive than chest radiography for detecting pleural plaques and for discriminating between pleural fibrosis and extrapleural fat. HRCT is also more sensitive than chest radiography or conventional CT for detecting parenchymal abnormalities in asbestos-exposed persons. The HRCT findings that correlate with other parameters of asbestosis include (1) septal and centrilobular thickening, (2) parenchymal fibrous bands, (3) honeycomb patterns, (4) subpleural density persisting in the prone position, and (5) subpleural curvilinear lines that persist in the prone position. CT has an important role in evaluating benign and malignant lung and pleural masses in asbestosis.

In plain English

This article was a review, not a new study. The authors described how computed tomography (CT), and especially high-resolution CT (HRCT), had been used to look for lung and pleural disease in people exposed to asbestos. They drew on published studies and on their own earlier work with a large group of occupationally exposed workers. They wrote that HRCT was more sensitive than chest X-rays for finding pleural plaques and for telling pleural fibrosis apart from fat lying outside the pleura. They listed five HRCT signs that matched other measures of asbestosis. These included thickened lines in the lung, fibrous bands, honeycomb patterns, and densities or curved lines just under the pleura that remained when the person lay face down. They wrote that scanning both face up and face down greatly improved the evaluation. In their experience, over 95% of patients whose chest X-rays were read as positive for asbestosis (ILO profusion 1/0 or higher) had HRCT scans compatible with asbestosis. They noted that CT could not tell mesothelioma apart from pleural or subpleural carcinoma. The authors concluded that CT had an important role in evaluating benign and malignant lung and pleural masses in 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: Narrative review of conventional CT and HRCT in asbestos-related lung and pleural disease, drawing on published studies and the authors' own experience
• Who was studied: No new study population. The review discussed asbestos-exposed persons in general, including a large group of occupationally exposed workers that the authors had analyzed in earlier work.
• Exposure: Asbestos exposure in general, mainly occupational. No specific fiber types, products or doses are given for the imaging findings.
• Main results:
  • The authors wrote that CT is more sensitive than chest radiography for detecting pleural abnormalities.
  • Five HRCT findings correlate with other measures of asbestosis: septal and centrilobular thickening; parenchymal fibrous bands; honeycomb patterns; subpleural density persisting in the prone (face-down) position; and subpleural curvilinear lines persisting in the prone position.
  • Scanning in both the supine (face-up) and prone positions greatly enhances evaluation of the lung tissue.
  • Although HRCT is better for evaluating the lung for asbestosis, the authors stated that conventional CT is successful in over 80% of cases.
  • In the authors' experience, the vast majority (over 95%) of patients with chest radiographs positive for asbestosis (ILO profusion 1/0 or higher) have abnormal HRCT scans compatible with asbestosis. This passage is in a scrambled part of the text.
  • In the authors' experience, calcification within pleural plaques is seen in about 5% more patients when CT or HRCT is used than when radiography is used. This passage is in a scrambled part of the text.
  • The authors reported finding that CT detects asymptomatic benign masses in up to 10% of workers with significant asbestos exposure, and that more than 90% of these masses are benign. This passage is in a scrambled part of the text.
  • CT findings cannot distinguish mesothelioma from pleural or subpleural carcinoma.
• The authors' conclusion: The authors concluded that CT has an important role in evaluating benign and malignant lung and pleural masses in asbestosis.
• Limitations the authors state:
  • HRCT examines the lung only at selected sampling sites, not the whole lung.
  • The subpleural dependent density seen on CT can also occur in people without lung abnormalities.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Lung cancer, Mesothelioma, Pleural plaques and thickening.

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

Related studies

• Conventional and high resolution computed tomography in the diagnosis of asbestos-related diseases — D.A. Lynch, G. Gamsu, et al. (1989)
• High-resolution computed tomography of asbestos-related diseases — D.R. Aberle (1991)
• Computed tomography of asbestos-related pleural abnormalities — M. Tiitola, L. Kivisaari, et al. (2002)
• The usefulness of computed tomography in detecting asbestos-related pleural abnormalities in people who had indeterminate chest radiographs: the Libby, MT, experience — O.I. Muravov, W.E. Kaye, et al. (2005)
• Clinical value of fluorodeoxyglucose-positron emission tomography/computed tomography in differentiation of malignant mesothelioma from asbestos-related benign pleural disease: an observational pilot study — H. Yildirim, M. Metintas, et al. (2009)
• Computed tomography features in malignant pleural mesothelioma and other commonly seen pleural diseases — M. Metintas, I. Ucgun, et al. (2002)

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