Performing high-resolution computed tomography in asbestos-exposed patients

Our plain-English summary of Performing high-resolution computed tomography in asbestos-exposed patients, by T.C. McLoud (AJR. American Journal of Roentgenology, 1995).

The study

• Author: T.C. McLoud
• Journal: AJR. American Journal of Roentgenology
• Published: 1995;164(3):761-2
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This was a short expert answer in a journal's Questions and Answers column, not an original study. A physician asked what mild signs of lung fibrosis (scarring) on high-resolution CT (HRCT) mean in asbestos-exposed patients without asbestos-related pleural disease. The author explained that diagnosis still rested on 1986 American Thoracic Society criteria, which include chest X-ray, lung function and examination findings. Citing earlier work, the author noted two findings. First, 10% to 20% of people with asbestosis on tissue examination may have a normal X-ray. Second, one study found that about one third of 169 asbestos-exposed workers with normal X-rays had HRCT findings suggesting early asbestosis, though only a subgroup had abnormal lung function. The author wrote that these HRCT features are not unique to asbestosis and that their specificity had not been established. The author concluded that mild fibrosis on HRCT must be correlated with symptoms, physical findings and lung function tests before asbestosis can be diagnosed with confidence. The author also concluded that diagnosis for compensation should not rely solely on early HRCT changes.

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: Expert opinion: an answer to a reader's question in a journal Questions and Answers column; no new data were collected
• Who was studied: No participants were studied. The question concerned asbestos-exposed patients undergoing HRCT who have mild signs of pulmonary fibrosis but no asbestos-related pleural disease
• Exposure: Asbestos exposure in general; no fiber types, products or jobs are specified
• Main results:
  • The author stated that diagnosis of asbestosis was still based on the 1986 American Thoracic Society criteria. These criteria include small opacities of ILO profusion 1/1 or greater on chest X-ray, abnormal pulmonary function and inspiratory crackles, in people with a history of asbestos exposure.
  • Citing an earlier report, the author noted that between 10% and 20% of persons with histologic evidence of asbestosis may have a normal chest radiograph.
  • Citing Aberle et al., the author reported on 169 asbestos-exposed workers with normal chest radiographs. Approximately one third had HRCT findings suggesting early asbestosis, but only a subgroup of these had pulmonary function abnormalities.
  • The author wrote that the HRCT features described for early asbestosis appear to represent interstitial fibrosis but are not unique to asbestosis.
  • Citing one study, the author reported that no correlation was found between smoking history and the HRCT appearance of subpleural interstitial fibrosis.
  • The author considered it a reasonable conclusion that, in a person with nontrivial asbestos exposure, such HRCT findings provide evidence implicating asbestosis as the cause of the interstitial fibrosis.
• The authors' conclusion: The author concluded that in asbestos-exposed people, mild pulmonary fibrosis on HRCT must be correlated with symptoms, physical findings and pulmonary function abnormalities before asbestosis can be diagnosed with confidence. The author also stated that diagnosis, particularly for judicial compensation, should not rely solely on early fibrosis changes seen on HRCT.
• Limitations the authors state:
  • The author noted that few studies had correlated individual HRCT features of asbestosis with histopathology.
  • The author noted that HRCT lacked a standardized classification for interpretation comparable to the ILO system.
  • The author noted that progression of minimal HRCT findings had not been adequately studied.

Topics

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

Related studies

• High resolution computed tomography and lung function in asbestos-exposed workers with normal chest radiographs — C.A. Staples, G. Gamsu, et al. (1989)
• Pulmonary function, smoking habits, and high resolution computed tomography (HRCT) early abnormalities of lung and pleural fibrosis in shipyard workers exposed to asbestos — S. Neri, P. Boraschi, et al. (1996)
• 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)
• Findings from high resolution computed tomography of the lung and pleura of symptom free workers exposed to amosite who had normal chest radiographs and pulmonary function tests — S. Neri, A. Antonelli, et al. (1994)
• High-resolution computed tomography abnormalities in ex-insulators annually exposed to asbestos dust — J.M. Soulat, D. Lauque, et al. (1999)
• Agreement between chest radiography and high-resolution computed tomography in diagnosing dust-related interstitial lung fibrosis — R.R. Tiwari (2015)

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