Figure 2 (A-D).

A 70-year-old woman, a case of allergic bronchopulmonary aspergillosis with mild persistent asthma, total IgE level 3117.7 IU/mL and specific IgE to A. fumigatus of 0.97 kUA/L. Spirometry was suggestive of the restrictive pattern (FEV 1 Pre 82%, FEV1 Post 82%, FVC Pre 74%, FVC post 75%, MEF pre 53%, and MEF post 52%). (A) Coronal HRCT thorax image shows the calculation of total lung volume by using the threshold value of -500 to -1024 HU (1783 cc). Thresholding only picks up aerated lung tissue (pink areas) and leaves non-aerated tissue, pulmonary vessels, etc. The central airways have also been excluded. (B) Coronal HRCT thorax image shows the calculation of low-attenuation lung volume by using the threshold value of -851 to -950 HU. By using these threshold values only low-attenuation areas of lung are picked up (pink dots). Low-attenuation expiratory lung volume was 432 c.c. (C) Inspiratory HRCT thorax axial minimum intensity projection image reveals subtle mosaic perfusion areas (arrows). (D) Expiratory HRCT thorax axial minimum intensity projection image confirms the presence of air trapping areas (arrows)