[Update: standardized CT/HRCT classification of occupational and environmental thoracic diseases in Germany]

The high-resolution computed tomography (HRCT) coding scheme of the international classification of occupational and environmental respiratory diseases (ICOERD) presented here is an instrument for a standardized semiquantitative description of occupation and environment-linked as well as other pulmonary and pleural diseases. Analogous to the International Labour Organization (ILO) classification, the ICOERD coding scheme should always be used when the CT/HRCT examination is employed for occupational medical investigations or expert opinions. After publication of the guidelines and recommendations on diagnostics and expert assessment of asbestos-linked diseases and silicosis, the application of a standardized investigation program and assessment with the ICOERD classification form are obligatory, at least for the initial assessment. Furthermore, its use in the field of follow-up assessments of occupational diseases should be encouraged in order to guarantee comparability between individual reports (interreader variability) and at least a semiquantitative assessment of disease progression in isolated cases. Because the anatomical structures in projection radiography and CT are not presented identically, a 1:1 transfer of the results of the ILO classification to the CT/HRCT coding scheme is not possible. An overview image of the thorax does not allow overlap-free reproduction of structures, in contrast to CT. These methodological differences can in cases of isolated assessment result in different opinions of projection and CT images mostly by different investigators. In cases of discrepant opinions an integrated report of findings by combination of all information from both procedures is necessary.