High-resolution computed tomography of asbestos-related diseases

Our plain-English summary of High-resolution computed tomography of asbestos-related diseases, by D.R. Aberle (Seminars in Roentgenology, 1991).

The study

• Author: D.R. Aberle
• Journal: Seminars in Roentgenology
• Published: 1991;26(2):118-31
• Type of article: Review
• Cited by: 19 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. 004968).

Abstract

There is growing evidence that HRCT can detect both interstitial and pleural disease in advance of conventional clinical or radiographic studies. Limited HRCT scans are roughly competitive in time and cost with 4-view radiographic examinations. The use of limited HRCT for large-scale screening of asbestos-exposed individuals is controversial. Hopefully this will be resolved as we gain greater understanding of the specificity of HRCT and establish guidelines for standardizing technique and interpretation. At present, limited HRCT scans can supplement the chest radiographic evaluation of subjects in whom there is equivocal parenchymal or pleural disease, unexplained abnormalities on pulmonary function tests, or significant coexisting pleural disease that precludes evaluation of the underlying parenchyma. Interstitial abnormalities on HRCT may be reasonably ascribed to asbestos exposure when there is clear historical documentation of significant, remote dust exposure or concomitant evidence of typical bilateral asbestos-related pleural disease. A subpleural distribution of interstitial abnormality in nondependent lung is important to establish the diagnosis of interstitial fibrosis. Although both unilateral pleural and parenchymal fibroses have been reported, lesions should generally be present bilaterally. In individuals with combined asbestos-cigarette smoke exposure in whom symptoms or functional abnormalities are present, HRCT may play a central role in distinguishing emphysematous lung destruction from the peripheral interstitial changes of asbestosis. Finally, in individuals with significant pleural or parenchymal fibrosis, focal lung masses may not be visible on chest radiographs. In these individuals, CT protocols that sample all regions of the thorax are appropriate.

In plain English

This article was a review, not a new study. The author reviewed published work on high-resolution computed tomography (HRCT) in asbestos-exposed people. It covered asbestosis (interstitial fibrosis), asbestos-related focal lung masses including round atelectasis and lung cancer, and benign pleural disease such as circumscribed plaques and diffuse pleural thickening. One reviewed study looked at 100 asbestos-exposed individuals. Among the 45 workers with clinical asbestosis, HRCT was read as high probability for asbestosis in 85%. Among the 55 workers without clinical asbestosis, roughly one third also had high-probability readings. In another reviewed study of 169 asbestos workers with normal chest X-rays, HRCT suggested asbestosis in one third. The author noted that no studies of sufficient scale had addressed how specific HRCT is for asbestosis, and that HRCT lacked a standardized interpretation system. The author concluded that using limited HRCT for large-scale screening was controversial but that it could supplement chest X-rays in selected people. The author also concluded that CT sampling all regions of the chest was appropriate for people with significant pleural or lung fibrosis, in whom focal masses may not be visible on X-rays.

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 published studies on high-resolution CT (HRCT) in asbestos-related diseases
• Who was studied: No study population of its own. The review discussed published HRCT studies of asbestos-exposed workers and individuals.
• Exposure: Occupational asbestos exposure in general (mining, manufacture and use of asbestos products). No specific fiber types were named.
• Main results:
  • In a reviewed study of 100 asbestos-exposed individuals, HRCT readings among the 45 workers with clinical asbestosis were high probability for asbestosis in 85%, intermediate in 11% and low in 4%.
  • In the same reviewed study, roughly one third of the 55 workers who did not meet criteria for clinical asbestosis had high-probability HRCT readings.
  • In a reviewed study of 169 asbestos workers with normal chest radiographs, HRCT suggested asbestosis in one third.
  • In a reviewed comparison of 29 subjects with clinical asbestosis and 34 unexposed controls, curvilinear subpleural lines were seen with roughly equal frequency in subjects and controls.
  • The review stated that, in diffuse pleural thickening, HRCT virtually always shows fibrosis of the lung tissue just beneath the pleura.
• The authors' conclusion: The author concluded that limited HRCT for large-scale screening of asbestos-exposed people was controversial. The author considered that limited HRCT can supplement chest radiographs in selected cases. For people with significant pleural or parenchymal fibrosis, the author considered CT covering all regions of the chest appropriate.
• Limitations the authors state:
  • No studies of sufficient scale had addressed the specificity of HRCT for asbestosis.
  • HRCT lacked a standardized interpretation system comparable to the ILO chest radiograph classification.
  • Limited HRCT protocols sample only parts of the chest and may miss focal masses.

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), Interstitial, Pulmonary Function Test (PFT), Parenchyma, Asbestos Exposure, Bilateral, Asbestos-Related Pleural Disease, Interstitial Fibrosis.

Related studies

• Conventional and high resolution computed tomography in the diagnosis of asbestos-related diseases — D.A. Lynch, G. Gamsu, et al. (1989)
• Agreement between chest radiography and high-resolution computed tomography in diagnosing dust-related interstitial lung fibrosis — R.R. Tiwari (2015)
• 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)
• High-resolution computed tomography in cases with environmental exposure to asbestos in Turkey — F. Topçu, H. Bayram, et al. (2000)
• 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)
• The comparison of high-resolution computed tomography findings in asbestosis and idiopathic pulmonary fibrosis — M. Akira, K. Morinaga (2016)

Browse more research in Seminars in Roentgenology, or return to medical research.