"Pleural plaques exhibit the so-called "incomplete border sign" on chest radiograph. The inner margin is often well-defined because it is tangential to the x-ray beam and the adjacent lung is a good contrast medium. The tapering outer margin is indistinct as it is en face to the x-ray beam and the chest wall provides less tissue contrast. Calcified plaques are more obvious than non-calcified plaques to be identified. Locations most commonly encountered include posterolateral, mediastinal, and diaphragmatic pleura 1. The appearance of plaques has been likened to that of a holly leaf, with thickened rolled and nodular edges 4."
"Pleural plaques are strongly associated with inhalational exposure to asbestos. There is an extremely long latency (typically 20 to 30 years) after the onset of exposure 1. As asbestos is primarily used in construction and machinery environments, asbestos-related diseases in general, including pleural plaques, are primarily seen in men."
"The plaques may be calcified; however, most (85-95%) are not 1,2."