Incremental value of oblique chest radiographs in the diagnosis of asbestos-induced pleural disease

Our plain-English summary of Incremental value of oblique chest radiographs in the diagnosis of asbestos-induced pleural disease, by E.L. Baker, R. Greene (American Journal of Industrial Medicine, 1982).

The study

• Authors: E.L. Baker, R. Greene
• Journal: American Journal of Industrial Medicine
• Published: 1982;3(1):17-22
• Cited by: 12 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. 001762).

Abstract

To assess the value of oblique chest radiographs in the diagnosis of asbestos-related pleural disease, we identified 100 asbestos-exposed construction workers and provided separate interpretations of the postero-anterior (PA), left anterior oblique (LAO), and right anterior oblique (RAO) projections using the International Labour Office (ILO) system. We found that the LAO projection identified left-sided pleural thickening more effectively than the PA view and the RAO view improved diagnosis of right-sided disease comparably. Of 62 cases of bilateral pleural thickening, only 43 (68%) were diagnosed by the PA projection alone. The increased diagnostic efficiency of approximately 50% in identifying bilateral pleural thickening appears to justify the routine use of oblique chest films in screening asbestos-exposed populations. Since bilateral pleural thickening among asbestos-exposed workers is an indicator of significant asbestos exposure and increased risk of other asbestos-induced conditions, early detection of this abnormality can lead to interventions designed to reduce asbestos-related morbidity and mortality.

In plain English

This study tested whether adding two angled (oblique) chest X-ray views to the standard back-to-front (PA) view helped detect asbestos-related pleural thickening. The workers were 100 men chosen at random from 303 white male sheet-metal workers. Their asbestos exposure was indirect, mainly from working next to others who removed or installed asbestos-containing materials. One certified radiologist read each view separately using the ILO classification system. Combining all three views, 62 workers had pleural thickening on both sides. Of these, 43 (reported as 68%) were identified on the PA view alone. The PA plus the left oblique view would have identified 46 (74%), and the PA plus the right oblique view 51 (82%). Thirteen workers with no pleural thickening on the PA view showed thickening on both sides on the oblique films. Disease missed on the PA view tended to be milder. The authors concluded that the roughly 50% gain in detection appears to justify routine oblique films when screening asbestos-exposed populations. They noted the films were not of optimum quality.

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: Comparison of chest X-ray projections (posteroanterior, left anterior oblique, right anterior oblique), each read separately by one radiologist, in a screened group of workers
• Who was studied: 100 unselected workers, a randomly selected subset of 303 white male sheet-metal workers screened in a survey of asbestos-exposed construction workers. All had worked more than 10 years in their trade and were aged 26 to 75. Place and dates of the survey are not stated.
• Exposure: Indirect asbestos exposure, mainly from working next to others who were removing or installing asbestos-containing materials. Fiber types and doses are not stated.
• Main results:
  • The left oblique (LAO) view identified 61 films with pleural thickening on one or both sides. The PA view identified 48.
  • Among workers whose PA reading was normal, 38% had pleural disease on the left oblique view and 44% had abnormalities on the right oblique view.
  • Of the 62 workers with pleural thickening on both sides (all three views combined), 43 (68%) were diagnosed by the PA view alone.
  • Using only the PA and left oblique views, 46 (74%) of the 62 would have been diagnosed with thickening on both sides.
  • Using the PA and right oblique views, 51 (82%) of the 62 would have been correctly diagnosed.
  • In 13 workers, the PA view showed no pleural thickening while the oblique films showed thickening on both sides.
  • Workers with normal PA films had less extensive and slightly thinner pleural thickening than those whose disease was seen on the PA film.
  • Of the films showing pleural thickening on both sides, 95.1% showed pleural plaques.
  • When the radiologist re-read 50 PA films, 41 of 50 received the same interpretation both times. Five films read as normal on one reading were read as showing disease on both sides on the other.
• The authors' conclusion: The authors concluded that adding oblique views increased their diagnostic efficiency by nearly 50%, and that this appears to justify routine oblique films in screening asbestos-exposed populations.
• Limitations the authors state:
  • The films were readable in all but one case but were not of optimum quality. 93% of readable films were ILO film quality 2.

Topics

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

Medical terms in this study, explained in our Lexicon: Chest X-Ray, Asbestos-Related Pleural Disease, Pleural Thickening, Bilateral, Asbestos Exposure.

Related studies

• Use of oblique chest roentgenograms in detecting pleural disease in asbestos-exposed workers — C.B. Sherman, S. Barnhart, et al. (1988)
• Risk and significance of chest radiograph and pulmonary function abnormalities in an elderly cohort of former nuclear weapons workers — M.A. Mikulski, P.G. Hartley, et al. (2011)
• The clinical diagnosis of asbestosis in this century requires more than a chest radiograph — R.M. Ross (2003)
• 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)
• The serratus anterior muscle on chest radiographs — D. Gilmartin (1979)
• Cardiorespiratory responses to incremental exercise in patients with asbestos-related pleural thickening and normal or slightly abnormal lung function — A. Miller, A. Bhuptani, et al. (1993)

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