Study Syllabus for Classification of Radiographs of Pneumoconioses
An example of ax is seen in the right first anterior interspace overlapping the right second anterior rib at its midportion. The small rounded opacities making up this ax have identifiable margins, unlike the more homogeneous appearance of the large opacities that are also present. The large opacities seen are consistent with those of pneumoconiosis, since a background of small opacities is also present. The prominent left hilum is appropriately indicated with the symbol hi.
Normal intercostal muscle shadows are well illustrated in this radiograph and should not be confused with pleural plaque. Note the slightly obliquely oriented soft-tissue margins best seen over the right anterolateral 6th and 7th ribs.
Examples of ax are seen in the upper zones bilaterally (short arrow) where small opacities demonstrate coalescence, with still-identifiable margins for the small opacities. There is also early formation of size A large opacities (long arrows) arising near the peripheral margins of both upper zones. Their combined longest dimensions suggest size B classification. Note the symbol di should be checked due to loss of volume in the right and left upper lobes. Symbol hi also should be checked to indicate hilar enlargement.