Agreement between chest radiography and high-resolution computed tomography in diagnosing dust-related interstitial lung fibrosis

Our plain-English summary of Agreement between chest radiography and high-resolution computed tomography in diagnosing dust-related interstitial lung fibrosis, by R.R. Tiwari (Toxicology and Industrial Health, 2015).

The study

• Author: R.R. Tiwari
• Journal: Toxicology and Industrial Health
• Published: 2015;31(3):235-8
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Although it has been suggested that high-resolution computed tomography (HRCT) scans can be obtained when plain radiographs are equivocal for the presence of interstitial lung fibrosis (ILF) caused by inhalation of dust, such as silica, asbestos fibres, etc., the specificity of the findings remains in question. The present study was carried out to compare the relative efficacy of chest radiography by conventional method and HRCT in evaluating ILF which included 22 workers exposed to fibrogenic dust, who were subjected to clinical examination, pulmonary function testing, posteroanterior chest radiography and HRCT. In the six subjects who had findings suggestive of ILF on HRCT, four had normal chest x-ray (CXR) while one each has been diagnosed as having tuberculosis and ILF on CXR. The agreement analysis between HRCT and CXR suggests that there was a poor agreement between HRCT and CXR (kappa = 0.34).

© The Author(s) 2013.

In plain English

This cross-sectional study compared ordinary chest X-rays with high-resolution CT scans (HRCT) for detecting lung scarring (interstitial lung fibrosis) caused by dust. It included 22 factory workers exposed to fibrogenic dust. The article does not say which dust. All the workers had a clinical examination, breathing tests, a chest X-ray and an HRCT scan. Two experienced occupational health radiologists read the X-rays, and a clinical radiologist read the HRCT scans. Of the six workers whose HRCT suggested fibrosis, four had a normal chest X-ray, one was diagnosed with tuberculosis on X-ray, and one was diagnosed with fibrosis on X-ray. HRCT showed fibrosis in three workers and pleural thickening in one, and none of these were seen on X-ray. Agreement between the two methods was poor (kappa 0.34). The author concluded that HRCT could be obtained when plain X-rays are unclear, because it shows lung tissue more clearly. The author also noted that there is little information that HRCT readings are more reliable than X-ray readings. The article's tables contain some inconsistent numbers.

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: Cross-sectional study comparing two imaging methods (chest X-ray and HRCT), using Cohen's weighted kappa to measure agreement
• Who was studied: 22 workers in a factory who were exposed to fibrogenic dust. Most were aged 50 to 59: 12 of 22, given as 54.6% in the text and 54.5% in Table 1. Four were current smokers, 11 ex-smokers and 7 non-smokers. The author is based at the National Institute of Occupational Health in Ahmedabad, India, but the article does not state where the factory was or when the study took place.
• Exposure: Occupational exposure to fibrogenic dust in a factory. The specific dust (for example silica or asbestos) is not identified for these workers. In Table 1, exposure duration was under 10 years for 6 workers, 10 to 19 years for 3, 20 to 29 years for 3, and 30 years or more for 10.
• Main results:
  • Among the 6 workers with HRCT findings suggestive of interstitial lung fibrosis, 4 had a normal chest X-ray, 1 was diagnosed with tuberculosis on X-ray, and 1 was diagnosed with interstitial lung fibrosis on X-ray.
  • Interstitial fibrosis in 3 workers and pleural thickening in 1 worker were seen on HRCT only, not on chest X-ray.
  • 12 workers were labelled normal on HRCT and 15 were labelled normal on chest X-ray. 10 were judged normal by both methods.
  • Agreement between HRCT and chest X-ray was poor (kappa 0.34). In this study, values below 0.4 were defined as poor agreement.
  • Breathing tests showed a restrictive type of lung function impairment in 18 workers, printed as 81.2%.
• The authors' conclusion: The author concluded that HRCT and chest X-ray agreed poorly, and that HRCT scans could be obtained when plain X-rays are unclear for dust-related pleural or lung fibrosis, because HRCT improves the visual clarity of lung tissue. The author also wrote that wider use of HRCT for compensation decisions should reduce unjust compensation caused by false-positive X-ray readings.
• Limitations the authors state:
  • No international or Indian coding system for reading HRCT was available. The two methods were therefore compared on the basis of provisional diagnoses.
  • The author notes there is little information that subjective HRCT interpretation is more reliable than subjective chest X-ray interpretation.

Topics

Medical terms in this study, explained in our Lexicon: Interstitial, Fibrosis, High-Resolution CT (HRCT), Fibrogenic, Chest X-Ray.

Related studies

• 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)
• 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)
• High-resolution computed tomography abnormalities in ex-insulators annually exposed to asbestos dust — J.M. Soulat, D. Lauque, et al. (1999)
• Early detection of interstitial lung disease in asbestos exposed non-smoking workers by mid-expiratory flow rate and high resolution computed tomography — Z. Dujić, J. Tocilj, et al. (1991)
• High resolution computed tomography and lung function in asbestos-exposed workers with normal chest radiographs — C.A. Staples, G. Gamsu, et al. (1989)
• Screening of miners and millers at decreasing levels of asbestos exposure: comparison of chest radiography and thin-section computed tomography — M. Terra-Filho, E. Bagatin, et al. (2015)

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