Figure 1

Sequential findings on thoracic CT and flow-volume loops. Sequential findings on thoracic CT and flow-volume loops from the day of admission (day1) to the day224. At day1 (Figure 1-A) showed a severe narrowing of the trachea,to approximately 4mm in diameter with moderate stenosis (5mm) in the right main bronchus, which accompanied by saw-tooth sign with trapezoidal shape on flow-volume loops. At day60 (Figure 1-B) revealed the improvement of the limitation of expiratory flow with the disappearance of the saw-tooth sign or trapezoidal shape as well as the amelioration of the stenosis both in the central airway and right main bronchus. At day207 (Figure 1-C), flow-volume loops showed the reproduction of the saw-tooth sign together with the progression of stenosis in the central airway (7mm), but not in the right bronchus. At day224 (Figure 1-D), after completion of inserting stent, saw-tooth sign completely disappeared.