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

Our plain-English summary of 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, by T. Tamura, N. Suganuma, K.G. Hering, et al (Industrial Health, 2015).

The study

• Authors: T. Tamura, N. Suganuma, K.G. Hering, T. Vehmas, H. Itoh, M. Akira, Y. Takashima, H. Hirano, Y. Kusaka
• Journal: Industrial Health
• Published: 2015;53(3):260-70
• Cited by: 36 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The International Classification of High-resolution Computed Tomography (HRCT) for Occupational and Environmental Respiratory Diseases (ICOERD) has been developed for the screening, diagnosis, and epidemiological reporting of respiratory diseases caused by occupational hazards. This study aimed to establish a correlation between readings of HRCT (according to the ICOERD) and those of chest radiography (CXR) pneumoconiotic parenchymal opacities (according to the International Labor Organization Classification/International Classification of Radiographs of Pneumoconioses [ILO/ICRP]). Forty-six patients with and 28 controls without mineral dust exposure underwent posterior-anterior CXR and HRCT. We recorded all subjects' exposure and smoking history. Experts independently read CXRs (using ILO/ICRP). Experts independently assessed HRCT using the ICOERD parenchymal abnormalities grades for well-defined rounded opacities (RO), linear and/or irregular opacities (IR), and emphysema (EM). The correlation between the ICOERD summed grades and ILO/ICRP profusions was evaluated using Spearman's rank-order correlation. Twenty-three patients had small opacities on CXR. HRCT showed that 21 patients had RO; 20 patients, IR opacities; and 23 patients, EM. The correlation between ILO/ICRP profusions and the ICOERD grades was 0.844 for rounded opacities (p<0.01). ICOERD readings from HRCT scans correlated well with previously validated ILO/ICRP criteria. The ICOERD adequately detects pneumoconiotic micronodules and can be used for the interpretation of pneumoconiosis.

In plain English

This study compared two ways of grading dust-related lung changes: the ILO system for chest X-rays and a newer system for high-resolution CT scans (ICOERD). It included 74 men in Fukui, Japan: 46 hospital outpatients with occupational mineral dust exposure, mostly from tunnel work and mining, and 28 clerical workers without such exposure. Only one patient was confirmed to have asbestos exposure. Three certified readers graded the X-rays and three developers of the CT system graded the scans. On X-ray, 23 men had small opacities, including 22 of the 46 exposed men and 1 of the 28 controls. On CT, 21 men had rounded opacities, 20 had irregular opacities and 23 had emphysema. X-ray and CT scores for rounded opacities correlated at 0.844 (p less than 0.01, 73 men). Readers agreed less well with each other on irregular opacities and emphysema. The authors concluded that the CT system may be useful for studying pneumoconiosis micronodules. They noted a small sample that was not population-based, and said they could not study how irregular opacities on X-ray related to those on CT.

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 comparison of two radiological classification systems: chest X-rays read by the ILO/ICRP system and HRCT scans read by the ICOERD system, in the same subjects
• Who was studied: 74 men in Fukui, Japan. 46 had occupational mineral dust exposure and were outpatients at Koyo Seikyo Hospital seen for suspected pneumoconiosis. 28 controls had no occupational mineral dust exposure and were recruited from clerical offices. There were 39 current smokers, 32 ex-smokers and 3 non-smokers.
• Exposure: Mineral dust (for example crystalline silica, asbestos, cement). By longest job: 4 in tunnel transportation, 20 in tunnel excavation, 21 mineworkers and 1 in cement work. The median total dust exposure was 31 years (range 5 to 52). Only one patient was confirmed to have asbestos exposure.
• Main results:
  • On chest X-ray (median of 3 readers), 23 of the 74 subjects had small parenchymal opacities. In 22 the main shape was rounded and in 1 it was irregular.
  • Mineral dust exposure history was significantly related to pneumoconiosis on X-ray (p<0.01). Pneumoconiosis was found in 22 of the 46 exposed men and 1 of the 28 controls.
  • On HRCT (median of 3 readers), 21 subjects had well-defined rounded opacities, 20 had irregular opacities, 23 had emphysema, 1 had ground glass opacities and 1 had honeycombing.
  • Agreement between pairs of readers: the mean kappa was 0.772 for X-ray profusion. For CT, the mean weighted kappa was 0.538 for rounded opacities, 0.212 for irregular opacities and 0.399 for emphysema.
  • Among 73 subjects, the X-ray profusion of small rounded opacities and the CT summed grade of rounded opacities had a Spearman correlation of 0.844 (p<0.01). One subject whose X-ray opacities were mainly irregular, with no rounded opacities on CT, was excluded.
  • One control, a clerical worker, had pneumoconiosis-type opacities on X-ray. No reader found rounded or irregular opacities on his CT, but 2 of 3 readers found emphysema. He had smoked for 80 pack-years, and the authors judged his emphysema to be caused by smoking.
• The authors' conclusion: The authors concluded that there is an adequate association between the two systems for pneumoconiotic micronodules. They said readings were mostly in agreement, suggesting the ICOERD may be useful for clinical and epidemiological studies of pneumoconiosis in terms of micronodules.
• Limitations the authors state:
  • Subjects were selected from a local hospital and were not population-based.
  • The sample was small, and the selection criteria and small size may have biased the results.
  • Agreement between readers was poor for irregular opacities and emphysema. The readers held no agreement meeting before reading.
  • The study focused on small rounded opacities. Only one patient had confirmed asbestos exposure, and even in this patient small rounded opacities predominated.
  • The authors could not study the relationship between irregular opacities on X-ray and irregular opacities on CT. They also could not fully study correlations between the CT grades for irregular opacities, emphysema, honeycombing or ground glass opacities and the X-ray findings.

Topics

Medical terms in this study, explained in our Lexicon: High-Resolution CT (HRCT), Emphysema, Pneumoconiosis.

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• 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)
• Agreement between chest radiography and high-resolution computed tomography in diagnosing dust-related interstitial lung fibrosis — R.R. Tiwari (2015)

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