Abstract

ILO Classification of Radiograph of Pneumoconioses (ILO/ICRP) has played an important role in screening and surveillance of pneumoconiosis among dust exposed workers worldwide. As the ILO/ICRP has semi-quantitative scheme, it allows objective and standardised recording of radiographic findings on chest radiographs of workers. The International Classification of HRCT for Occupational and Environmental Respiratory Diseases (ICOERD) have been proposed from International Expert Team consists of researchers from 7 countries, based on the consensus report at the Helsinki Meeting for Asbestos related diseases in 2000. The ICOERD system covers all aspect of Occupational and Environmental Respiratory Diseases, starting with six parenchymal findings and two pleural abnormalities. Parenchymal findings include well-defined rounded opacities, irregular opacities, inhomogeneous attenuation, honeycombing, emphysema and large opacities. Irregular opacities include intralobular opacities and interlobular opacities, the former include centrilobular opacities suggestive of inhalation diseases. The ICOERD classifies these parenchymal findings in 4-point-scale, grading 6 lungs zones. Consequently, the final grade for each of the parenchymal findings sums up to 18-point-scale. Pleural abnormalities cover pleural thickening of parietal and/or visceral types. Width and extent of pleural thickening is graded in 4-point-scale. As multi-detector CT can be used for screening of non-malignant and malignant diseases, the ICOERD added supplemental coding for mesothelioma, which allows standardised recording of findings suggestive of mesothelioma. CT findings of unilateral pleural effusion, nodular pleural thickening, mediastinal pleural thickening, interlobar fissure thickening, diminished lung, contracted hemithorax should be noticed when reviewing CT scans of asbestos-exposed persons.