High-resolution computed tomography in cases with environmental exposure to asbestos in Turkey

Our plain-English summary of High-resolution computed tomography in cases with environmental exposure to asbestos in Turkey, by F. Topçu, H. Bayram, M. Simşek, et al (Respiration; International Review of Thoracic Diseases, 2000).

The study

• Authors: F. Topçu, H. Bayram, M. Simşek, K. Kaya, C. Ozcan, R. Işik, A. Senyiğit
• Journal: Respiration; International Review of Thoracic Diseases
• Published: 2000;67(2):139-45
• Type of article: Comment
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background And Objectives: Although all parts of the lung can be affected as a consequence of asbestos exposure, most CT protocols tend to scan only the middle and lower parts of the thorax. The aim of this study was to investigate parenchymal and pleural lesions of persons exposed to environmental asbestos, using a high-resolution computed tomography (HRCT) protocol scanning the whole thorax.

Methods: We analyzed the chest radiographs and HRCT scans of 26 patients who presented bilaterally with multiple pleural plaques related to environmental asbestos exposure.

Results: Twenty-four cases (92%) had an abnormal HRCT suggestive of asbestosis. Apart from common HRCT changes related to asbestosis, we detected apical pleural thickening (APT) in 9 cases as well as a coarse honeycomb pattern adjacent to APT in 7 of these cases. Cavitary lesions due to pulmonary tuberculosis were observed on HRCT scans from 4 patients in total. Neither apical pulmonary fibrosis nor cavitary lesions were visible on chest radiographs.

Conclusions: We suggest that the HRCT protocol for examining asbestos-exposed individuals with pleural plaques on chest X-rays should include the whole thorax, since the asbestos-related pathologies may involve all parts of the lung.

Copyright 2000 S. Karger AG, Basel.

In plain English

This study, from a chest clinic in Diyarbakır, Turkey, examined 26 patients (15 men, 11 women; mean age 55). All lived or had lived in villages where soil containing asbestos was used as a whitewash on buildings, and their exposure began at birth or early childhood. All had extensive pleural plaques on both sides on chest X-rays. The authors compared the X-rays with high-resolution CT (HRCT) scans covering the whole chest. X-rays showed lung-tissue abnormalities in only 2 patients (8%), while HRCT showed changes the authors judged suggestive of asbestosis in 24 (92%). Thickening of the pleura at the top of the lung (apical pleural thickening) was found in 9 patients, 2 of them on HRCT only. Seven of these 9 had coarse honeycombing next to it. HRCT also showed cavities in 4 patients that were not visible on X-ray, and tuberculosis bacteria grew from these patients' sputum. The authors concluded that asbestosis can involve the upper lung and that CT scans of such patients should cover the whole chest. Asbestosis was not confirmed by tissue samples.

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: Descriptive imaging study (case series) comparing chest X-rays with whole-thorax high-resolution CT in patients with asbestos-related pleural plaques
• Who was studied: 26 patients (15 male, 11 female; mean age 55 years, range 32 to 72) presenting or referred for respiratory symptoms to the chest clinic of the University of Dicle, Diyarbakır, Turkey. All had bilateral multiple pleural plaques on chest X-ray. Study dates are not given.
• Exposure: Environmental (non-occupational) exposure from living in villages where soil containing asbestos was used as a whitewash for buildings. Exposure began at birth or early childhood. Median duration of exposure was 28 years (range 10 to 55) and mean latency was 55 years. This study did not identify the fiber type; the introduction cites earlier work reporting tremolite in such stucco.
• Main results:
  • On chest X-ray, lung-tissue (parenchymal) abnormalities of ILO profusion 1/0 or more were present in only 2 of the 26 patients (8%).
  • On HRCT, 24 of the 26 patients (92%) had abnormal scans suggestive of asbestosis. The 2 patients with no pulmonary abnormalities on HRCT (both women) were excluded from further analysis.
  • Parenchymal bands (92%) were among the most common HRCT findings compatible with asbestosis.
  • Thickened interlobular septal lines were seen on HRCT in 21 cases (81%).
  • Apical pleural thickening was found in 9 patients: 7 by both chest X-ray and HRCT, and 2 by HRCT only. The mean width on X-ray was 23.6 mm (range 12 to 40 mm).
  • Of the 9 patients with apical pleural thickening, 7 also had apical pulmonary fibrosis (coarse honeycombing adjacent to the thickening) on HRCT.
  • In 4 patients, HRCT showed cavitary lesions at the lung apices that were not seen on chest X-ray. M. tuberculosis was identified in their sputum cultures.
  • Mean vital capacity was 63.9% of predicted. It was not significantly lower in patients with diffuse pleural thickening or costophrenic angle obliteration than in those with only pleural plaques.
  • Smoking did not correlate with HRCT findings.
• The authors' conclusion: The authors concluded that the upper parts of the lung can be involved in asbestosis, at least in patients with bilateral pleural plaques. They concluded that CT (preferably HRCT) for findings suggestive of asbestosis should include the whole thorax.
• Limitations the authors state:
  • Asbestosis was not confirmed by tissue (histologic) examination.
  • A healed apical tuberculosis could not be completely ruled out as a cause of the apical changes.

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: Environmental Exposure, Asbestos Exposure, Thorax, High-Resolution CT (HRCT), Chest X-Ray, Pleural Plaques, Pleural Thickening, Pulmonary Fibrosis.

Related studies

• Conventional and high resolution computed tomography in the diagnosis of asbestos-related diseases — D.A. Lynch, G. Gamsu, et al. (1989)
• 3-Dimensional Quantification of Composite Pleural Plaque Volume in Patients Exposed to Asbestos Using High-resolution Computed Tomography: A Validation Study — G. Dournes, A. Dubois, et al. (2019)
• 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 abnormalities in ex-insulators annually exposed to asbestos dust — J.M. Soulat, D. Lauque, et al. (1999)
• High resolution computed tomography and lung function in asbestos-exposed workers with normal chest radiographs — C.A. Staples, G. Gamsu, et al. (1989)
• 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)

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