Eggshell calcification in the chest

The ILO International Classification of Radiographs of Pneumoconioses is a system of classifying chest radiographs (X-rays) for persons with a (or, rarely, more than one) form of pneumoconiosis. The intent is to provide a standardized, uniform method of interpreting and describing abnormalities in chest x-rays that are thought to be caused by prolonged dust inhalation. [Source: Wikipedia ]