Fig. 1

Chest high-resolution CT findings. a Ground glass and dense consolidations with patchy distribution were observed in the bilateral lungs before steroid pulse therapy. b 3 months after steroid pulse therapy, the bilateral dense consolidation seen in (a) was resolved. c 8 months after steroid pulse therapy, newly developed bilateral opacities were seen (arrowheads). d 1 year after the initiation of pirfenidone add-on therapy