Figure 14b. BAC in a 36-year-old woman. (a) Transaxial thin-section (1-mm collimation) CT scan (lung window) obtained at the level of the aortic arch show a 15-mm nodular area of ground-glass attenuation with a lobulated margin in the left upper lobe. Note also the dark bubble within the lesion (arrow). (b) On an FDG PET scan, the lesion demonstrates little glucose uptake (arrowhead) compared with other non-small cell lung cancers (not shown).