Fig. 2

a Inspiratory cross-sectional; b Expiratory cross-sectional; c Inspiratory coronal; d Expiratory coronal. Areas of hypo- and hyper-attenuation (thin arrows), which are more evident on expiratory scans, showing mosaic perfusion. Traction bronchiectasis is also shown (thick dotted arrows). The images show features recognised to be associated with bronchiolitis obliterans, including: mosaic perfusion, air trapping, vascular attenuation, bronchiectasis and peribronchial thickening, as seen in the mosaic pattern of attenuation of both lung fields