Imaging of occupational lung disease

Our plain-English summary of Imaging of occupational lung disease, by K.I. Kim, C.W. Kim, M.K. Lee, et al (Radiographics, 2001).

The study

• Authors: K.I. Kim, C.W. Kim, M.K. Lee, K.S. Lee, C.K. Park, S.J. Choi, J.G. Kim
• Journal: Radiographics
• Published: 2001;21(6):1371-91
• Type of article: Review
• Cited by: 77 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Occupational lung disease comprises a wide variety of disorders caused by the inhalation or ingestion of dust particles or noxious chemicals. These disorders include pneumoconiosis, asbestos-related pleural and parenchymal disease, chemical pneumonitis, occupational infection, hypersensitivity pneumonitis, and organic dust toxic syndrome. Most of these disorders produce diffuse lung disease. Although many of the disorders can be detected at chest radiography, high-resolution computed tomography (CT) has been shown to be superior to chest radiography in depicting parenchymal, airway, and pleural abnormalities. Some occupational lung diseases have characteristic radiologic features suggesting the correct diagnosis, whereas in others, a combination of clinical features, related occupational history, radiologic findings, and literature supporting an association between the exposure and the disease process is required for diagnosis. With advances in chest radiology, including high-resolution CT, radiologists play a key role in the clinical evaluation of occupational lung diseases and should continue their involvement in the diagnosis and treatment of these diseases.

In plain English

This article was an educational review by radiologists and an internist in Korea, not an original study. The authors described the occupations, disease processes and chest X-ray and CT appearances of a range of work-related lung diseases. These included silicosis and other pneumoconioses, asbestos-related pleural and lung disease, chemical injury, infections, hypersensitivity pneumonitis and organic dust toxic syndrome, illustrated with images from individual patients. In the asbestos section, the authors described pleural plaques as the most common manifestation of asbestos exposure. They wrote that diffuse pleural thickening, unlike plaques, is frequently associated with functional impairment. They called high-resolution CT, including prone scans, a sensitive way to detect abnormalities in asbestos-exposed people, but noted that CT findings of early asbestosis are nonspecific. Citing earlier literature, they stated that lung cancer develops in an estimated 20%–25% of heavily exposed workers and that an asbestos worker's lifetime mesothelioma risk is approximately 10%. The authors concluded that some occupational lung diseases have characteristic imaging features. For others, they wrote, diagnosis needs clinical features, occupational history and imaging together.

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: Educational review (an RSNA education exhibit) of the imaging of occupational lung diseases, illustrated with individual patient cases
• Who was studied: No study population. The article used illustrative individual patients. The asbestos cases were a 50-year-old man exposed in a brake lining production plant (pleural plaques, diffuse pleural thickening, rounded atelectasis, and asbestosis proved at open lung biopsy), a 63-year-old man with calcified pleural plaques, a 62-year-old man with asbestosis, and men aged 51 and 66 with malignant mesothelioma. The article does not say how the cases were selected.
• Exposure: Many occupational agents were reviewed (silica, coal, iron, carbon black, hard metal, chemicals, infections, organic dusts). For asbestos, the article described serpentine and amphibole fibers, with chrysotile said to account for more than 90% of asbestos used in the United States. Sources named were asbestos mining and processing, and secondary occupations such as insulation and textile manufacturing, construction, shipbuilding, and gasket and brake lining manufacture and repair.
• Main results:
  • The review described pleural plaques as the most common manifestation of asbestos exposure, a marker of exposure not usually associated with symptoms or functional impairment, with calcification in approximately 5%–15% of patients (citing earlier work).
  • The review stated that diffuse pleural thickening is less specific to asbestos than pleural plaques and, unlike plaques, is frequently associated with functional impairment.
  • The review stated that there is at present no definite evidence linking benign asbestos pleural effusion to later malignant pleural mesothelioma.
  • The review described high-resolution CT including prone scans as a sensitive, reliable means of detecting chest abnormalities in asbestos-exposed individuals.
  • The review stated that CT findings of early asbestosis are nonspecific and do not necessarily indicate asbestosis even when pleural plaques are present. Without pathologic proof, it said, diagnosis must rest on all available clinical, physiologic and radiologic information.
  • The review described rounded atelectasis as the most common benign mass caused by asbestos exposure, always accompanied by pleural thickening.
  • Citing earlier literature, the review stated that bronchogenic carcinoma develops in an estimated 20%–25% of workers heavily exposed to asbestos. It also stated that in asbestos workers who smoke the risk may be as much as 80–100 times that of nonsmoking, nonexposed people.
  • Citing earlier literature, the review stated that an asbestos worker's lifetime risk of mesothelioma is approximately 10%. It said household members and people living near asbestos mines and plants are also at risk, with a latency of approximately 20–40 years.
• The authors' conclusion: The authors concluded that some occupational lung diseases have characteristic imaging features suggesting the diagnosis. In others, they wrote, a definite diagnosis cannot be made from imaging alone, but combining clinical features, occupational history and radiologic findings improves diagnostic accuracy. They also concluded that radiologists should stay involved in evaluating these diseases.

Topics

Medical terms in this study, explained in our Lexicon: Occupational Lung Disease, Pneumoconiosis, Pneumonitis, Occupational History, High-Resolution CT (HRCT).

Related studies

• Imaging of Occupational Lung Disease — J. Champlin, R. Edwards, et al. (2016)
• Causative factors, imaging findings, and CT course of round atelectasis — L. Azour, T. Billah, et al. (2018)
• Occupational lung diseases and global occupational health on the Net — K. Takahashi, A. Sekikawa, et al. (1998)
• Widening perspectives of occupational lung disease — I.J. Selikoff (1973)
• ACR Appropriateness Criteria Review ACR Appropriateness Criteria® Occupational Lung Diseases — Expert Panel on Thoracic Imaging, L. Bacchus, et al. (2016)
• Relationships (I) of International Classification of High-resolution Computed Tomography for Occupational and Environmental Respiratory Diseases with the ILO International Classification of Radiographs of Pneumoconioses for parenchymal abnormalities — T. Tamura, N. Suganuma, et al. (2015)

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