Changes to ILO Classification and B-Reading System Now Being Implemented

Changes to ILO Classification and B-Reading System Now Being Implemented

The National Institute for Occupational Safety and Health (NIOSH) and the International Labor Office (ILO) have recently updated the ILO classification system used to evaluate chest radiographs for the presence and severity of changes associated with pneumoconiosis so that modern digital chest images can be classified using the system. On November 17, 2011, ILO issued the following Guidelines for the use of the ILO International Classification of Radiographs of Pneumoconioses, revised edition 2011 (view attachment below). This is the first update to the ILO Guidelines in over a decade.

The principal focus of the new guidelines is to extend the applicability of the Classification to digital chest images. Rather than using printed guides, B readers will now be required to acquire digital reference images from the ILO and compare them side by side with the subject images when B-reading. This change will improve accuracy and should reduce reader error. NIOSH and the ILO will also create a digital data bank from which radiologists can share and nominate new candidate images.

B readers are licensed physicians who have demonstrated proficiency in the classification of chest radiographs for pneumoconiosis using the ILO Classification System. To obtain certification, candidates must pass an examination that involves classifying 125 radiographs in 6 hours, with a score of at least 50 points out of 100. To reflect the new Guidelines, this exam is being revised to incorporate digital imaging. According to the CDC, only about half of applicants pass. [1]

In addition, Chest magazine has published a NIOSH-sponsored study of ILO screening, which concerns a comparison of x-ray films versus digital radiology. The study concludes that small opacities are better identified on digital images than conventional film. The article also indicates that there is significant inter-reader variability in finding small opacities, regardless of the imaging medium. [2]

These developments are significant in the litigation of asbestos claims involving lung cancer and asbestosis. For example, most or all ILO screening will now be done on digital film. Therefore, if a digital image does not indicate the finding of small opacities, this makes the argument that it is not asbestos-caused lung cancer more persuasive. Likewise, if film interpretations show opacities that are not confirmed by digital studies, defense attorneys could argue that the prior findings were error.

Governo Law Firm carefully monitors the latest developments in science and medicine so that we can best advocate for our clients in asbestos and other toxic tort cases. Please contact David Governo if you would like more information on this topic and how it may impact your company.

[1] "The NIOSH B Reader Program.", November 17, 2011.

[2] "Intramodality and Intermodality Comparisons of Storage Phosphor Computed Radiography and Conventional Film-Screen Radiography in the Recognition of Small Pneumoconiotic Opacities." Chest, December 2011 140:61574-1580; published ahead of print May 26, 2011.

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