ILO description of radiographic features of pneumoconioses B

* Extent refers to the longitudinal dimension of the pleural abnormality relative to the chest wall. The box in the image shows that the pleural plaque is up to ¼ the length of the lateral chest wall, which is designated by "1." In contrast, the pleural thickening on the left side of the same image is between ¼ and ½ of the lateral chest wall on that side, which is designated by a "2."
• Width refers to the thickness of the pleural abnormality. The measurement of width is made from the innermost margin of the rib to the innermost sharp margin of the plaque at the pleural-parenchymal boundary. Thus, in a given patient, if the thickness is 4 mm, it would be designated by "a," but if 7 mm, by "b."