Screening for asbestos-related pleural disease with digital storage phosphor radiography

Our plain-English summary of Screening for asbestos-related pleural disease with digital storage phosphor radiography, by C.M. Schaefer, R. Greene, L.C. Oliver, et al (Investigative Radiology, 1990).

The study

• Authors: C.M. Schaefer, R. Greene, L.C. Oliver, R.C. Lanza, D. Hall, S.R. Lindemann, H.J. Llewellyn, K.A. McCarthy, E. Pile-Spellman, J.R. Rubens
• Journal: Investigative Radiology
• Published: 1990;25(6):645-50
• Cited by: 5 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. 003648).

Abstract

Digital storage phosphor radiography (SR) has a wide dynamic range and unique postprocessing capabilities that may improve the performance of screening studies for asbestos-related pleural disease compared with conventional film radiography (FR). In a group of 32 asbestos-exposed and nine control subjects with established pleural data, we compared the screening performance of FR and SR obtained with a single isoexposure, dual-energy technique (system resolution 0.2 mm, 10 bits). Performance was evaluated for 7320 observations by eight readers using a paired t test (P less than .02 with Bonferroni correction) of averaged receiver operating characteristic curve (ROC) areas (Az +/- standard error). We found that SR alone and SR supplemented by dual-energy soft-tissue and calcium images (SRde) were superior to FR in the overall detection of pleural abnormalities (Az = 0.90 +/- 0.01, 0.90 +/- 0.01, and 0.88 +/- 0.01, respectively). In the specific detection of pleural calcification, SRde was superior to FR (Az = 0.91 +/- 0.01 and 0.87 +/- 0.01, respectively; P less than 0.01). Analysis of variance indicated that SRde most closely reproduced an established pleural score based on the International Labor Organization (ILO) classification of the pneumoconioses (P less than 0.05, Scheffé's multiple comparison test). We conclude that isodose SR performs at least as well as FR in screening for asbestos-related pleural disease. SR supplemented by dual-energy images might improve the specific detection of pleural calcifications compared with FR.

In plain English

This study compared conventional film chest X-rays with digital storage phosphor X-rays for detecting asbestos-related pleural disease. The digital images were tested alone and with added dual-energy images, separate soft-tissue and calcium images from one exposure. The subjects were 32 asbestos-exposed men under surveillance at an occupational health clinic and nine male controls. Readers viewed 61 selected half-chests (hemithoraces), each with all three methods. Eight readers made 7320 observations. Accuracy was scored as the area under a curve, where 1.0 is perfect. For overall detection of pleural abnormalities, digital images alone and digital with dual-energy images each scored 0.90, and film scored 0.88. For pleural calcification, digital with dual-energy images scored 0.91 and film scored 0.87. Detection of overall pleural thickening was equivalent across the three methods. All methods underestimated established pleural scores, and the dual-energy images agreed most closely with them. The authors noted that the practical significance of the differences may be minimal. They concluded that digital radiography performs at least as well as film, and that dual-energy images might improve detection of pleural calcifications.

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: Diagnostic imaging comparison (reader study using receiver operating characteristic analysis) of conventional film radiography versus digital storage phosphor radiography, with and without dual-energy images
• Who was studied: 32 asbestos-exposed men under surveillance in an occupational health clinic and 9 male control subjects (Massachusetts General Hospital, Boston). Of 82 hemithoraces (half-chests), 61 were selected: 52 from asbestos-exposed and 9 from control subjects. Each was viewed with all three imaging methods.
• Exposure: Known asbestos exposure (fiber types and jobs not specified). The comparison of interest was the imaging method: film radiography, digital storage phosphor radiography, and digital radiography supplemented with dual-energy soft-tissue and calcium images.
• Main results:
  • Overall detection of pleural abnormalities (7320 observations, 8 readers): digital alone and digital with dual-energy images were superior to film. Area under the curve was 0.90 plus or minus 0.01 for each digital method versus 0.88 plus or minus 0.01 for film (P less than .02).
  • Pleural thickening (4392 observations): the three methods were equivalent for overall, en face and diaphragmatic thickening. For en profile thickening, digital with dual-energy images was superior to film (0.92 versus 0.89, P less than .01).
  • Overall pleural calcification (2928 observations): digital with dual-energy images was superior to film (0.91 plus or minus 0.01 versus 0.87 plus or minus 0.01, P less than .01). Digital alone and film were equivalent.
  • In the scrambled text, the diaphragmatic calcification finding appears to be that digital alone and digital with dual-energy images were superior to film (0.90, 0.91 and 0.86 respectively, P less than .02). All three methods appear to have been equivalent for chest wall calcification.
  • In reproducing established pleural scores (two readers), all methods underestimated the score (P less than .005). Digital with dual-energy images agreed most closely (P less than .05, Scheffé's test). Mean differences from the established scores were 0.51 for digital with dual-energy, 1.37 for digital alone and 1.54 for film (each plus or minus 0.17).
• The authors' conclusion: The authors concluded that digital storage phosphor radiography at the same dose performs at least as well as film in screening for asbestos-related pleural disease. They added that supplementing it with dual-energy images might improve the specific detection of pleural calcifications compared with film.
• Limitations the authors state:
  • The 95% confidence intervals of the statistically significant differences overlapped considerably, so the practical significance of the differences may be minimal.
  • Asbestos-related lung disease was not studied because it was uncommon in the study group.
  • The performance of the dual-energy images was limited by increased background noise.

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: Asbestos-Related Pleural Disease, Pleural Calcification.

Related studies

• Improved detection of asbestos-related pleural plaques with digital radiography — R. Greene, C.M. Schaefer, et al. (1991)
• Comparison of chest digital tomosynthesis and chest radiography for detection of asbestos-related pleuropulmonary disease — G. Lee, Y.J. Jeong, et al. (2013)
• Commentary on: Comparison of chest digital tomosynthesis and chest radiography for detection of asbestos-related pleuropulmonary disease — I. Vlahos (2013)
• Diagnostic Performance of Ultra-Low-Dose Computed Tomography for Detecting Asbestos-Related Pleuropulmonary Diseases: Prospective Study in a Screening Setting — M. Schaal, F. Severac, et al. (2016)
• Comparison of digital with film radiographs for the classification of pneumoconiotic pleural abnormalities — T.C. Larson, D.B. Holiday, et al. (2012)
• Asbestos-related pleural disease and asbestosis: a comparison of CT and chest radiography — A.C. Friedman, S.B. Fiel, et al. (1988)

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