This repository was compiled by the National Institute for Occupational Health (NIOH) in collaboration with South Africa’s Department of Employment and Labour (Department). It is a component of the Department’s Reduction of Silicosis in the Non-mining Sector project.
Introduction
This repository was compiled by the National Institute for Occupational Health (NIOH) in collaboration with South Africa’s Department of Employment and Labour (Department). It is a component of the Department’s Reduction of Silicosis in the Non-mining Sector project.
Purpose
The materials in the repository are for:
- Trainers to develop the skills of medical practitioners in identifying the radiologic features of the combined diseases of silicosis and tuberculosis1;
- Self-learning by medical practitioners. (The radiologic features of each disease alone are complex, but even more so with combined disease. Experience in reading chest radiographs is, therefore, necessary for effective self-learning.)
Non-commercial use permitted
Non-commercial use of the materials in the repository is permitted provided the Reduction of Silicosis in the Non-mining Sector, Department of Employment and Labour, is acknowledged. The materials can be adapted and altered, but this should be noted in the acknowledgement. Use of the articles published in scientific journals requires attribution of the journal.
Description of materials in the repository
The sections of the repository are:
- Links to free online training courses on the diagnosis of silicosis, and to the ILO International Classification of Radiographs of Pneumoconioses;
- Articles on the radiology of silicotuberculosis;
- Chest radiographs showing features of silicosis and tuberculosis, and tuberculosis in silica exposed individuals.
The repository is far from complete; it constitutes an initial set of materials with the intention of developing a more comprehensive repository by adding to it over time.
Footnote1. Tuberculosis here is not necessarily disease caused by Mycobacterium tuberculosis. Nontuberculous mycobacterial (NTM) disease occurs in silica exposed populations. The clinical and radiologic features may overlap.
Links to free online training courses on the diagnosis of silicosis and the ILO International Classification of Radiographs of Pneumoconioses
The repository does not cover the diagnosis of silicosis; this is covered by many texts and publications (a few are listed below). This section only provides links to free online training courses, and to the ILO International Classification of Radiographs of Pneumoconioses (ILO Classification).
Free online training courses on the diagnosis of silicosis
Only one course was found, that of the National Institute for Occupational Safety and Health (NIOSH), named Study Syllabus for Classification of Radiographs of Pneumoconioses. It can be found at https://www.cdc.gov/niosh/learning/b-reader/default.html
It is primarily on the ILO Classification but it also has a section on the Clinical Approach to the Diagnosis and Treatment of Occupational Lung Diseases.
The ILO International Classification of Radiographs of Pneumoconioses
The ILO Classification of Radiographs of Pneumoconioses has been in use for decades – in various iterations – and has been adopted globally. It is a systematic way of codifying radiologic features of pneumoconioses, and other changes seen on a chest x-ray. The 2022 version with digital radiographs is the latest. A link to download the Guidelines for the use of the ILO International Classification of Radiographs of Pneumoconioses, and standard digital radiographs is provided in this repository. The Guide and the radiographs are free. Among the ILO Classification standard radiographs are those showing small rounded opacities (p, q and r) and large opacities (A, B and C) that occur in silicosis. These standard radiographs are thus useful to familiarise readers with the typical features of silicosis.
Selected bibliography on silicosis
Leung CC, Yu ITS, Chen W. Silicosis. Lancet 2012; 379:2008-18.
Rees D, Murray J. Chapter 18 Silica. In: Parkes’ Occupational Lung Disorders. 4th Edition. Newman Taylor A, Cullinan P, Blanc P, Pickering A, Eds. CRC Press, Florida 2017; pp. 187–205.
Barnes H, Goh NSL, Leong TL, Hoy R. Silica-associated lung disease: An old-world exposure in modern industries. Respirology 2019: 24; 1165–1175. doi: 10.1111/resp.13695.
Hoy RF, Chambers DC. Silica-related diseases in the modern world. Allergy. 2020; 75: 2805-2817 https://doi.org/10.1111/all.14202.
A short guide on the radiologic features of silicosis and silicotuberculosis (combined disease)
In this guide, silicotuberculosis means silicosis with either inactive tuberculosis (stable, previous disease) or active tuberculosis (requiring treatment), or both. The guide briefly describes the typical radiologic features of silicosis, but the focus is on the radiologic changes on the chest x-ray suggestive of tuberculosis with silicosis. The guide is largely anecdotal.
Critique of the guide and comments are welcome. Email Info@nioh.ac.za
The guide does not cover the diagnosis of silicotuberculosis. A reference to a review article that includes diagnosis is:
Lanzafame M, Vento S. Mini-review: Silicotuberculosis. J Clin Tuberc Other Mycobact Dis 2021; 23: 100218. doi: 10.1016/j.jctube.2021.100218.
Articles on the radiology of silicotuberculosis
Recent articles describing the radiologic features of silicotuberculosis are scant. Consequently, only two articles are included in the repository. Both can be used non-commercially with attribution of the journal.
Recommendations for additional articles are welcome. Email info@nioh.ac.za
Chest images showing features of silicotuberculosis, or tuberculosis in silica exposed individuals
A library of chest radiographs with a summary of pertinent radiologic changes is included in the repository. The reports are based on readings (interpretations of the radiographs) of experienced readers. Reports are consensus readings of more than one reader. The reports are not comprehensive; many radiologic changes are not in the reports.
Reading chest radiographs is subjective and there is inter- and intra-reader variability. Also, even experienced readers may find it difficult to distinguish confidently between radiologic silicosis, inactive and active tuberculosis, and concurrent disease. Consequently, the reported radiologic changes are not presented as the “truth”, rather what experienced readers observed and concluded about the presence of silicosis, tuberculosis, or both. ( “Tuberculosis” does not exclude NTM disease; the radiologic features may overlap and not all cases had bacteriological confirmation of Mycobacterium tuberculosis disease. )
Comments on the radiographs and reports are welcome. Email info@nioh.ac.za
The source of the radiographs is:
Radiographs 1
Radiographs 2
Additional radiographs are being obtained, and they will be added to the repository.
The source of the radiographs is:
Radiographs 1 and 2 Prof. Albert Solomon
Radiographs 3 to 10 Dr Botembetume Maboso
Additional radiographs are being obtained, and they will be added to the repository.