Figure 14c.  Barrel-shaped thorax in a patient with diffuse panbronchiolitis (Asian bronchiolitis). (a) Axial chest CT scan shows a barrel-shaped thorax characterized by a relatively long anteroposterior diameter of the osseous thorax. (b, c) Posteroanterior chest radiograph (b) and schematic (c) show the straight, downward angulation of the lateral portion of the ribs (arrows in b), which become elongated as the sagittal diameter of the thorax increases.