Table 1

 CTBO scoring system for one lobe*

CT abnormalityScore
Bronchiectasis: peripheral is 1–2 cm from the costal/diaphragmatic pleura or abutting the mediastinal pleura; B, diameter of bronchial lumen; V, diameter of accompanying pulmonary artery.
Mucus plugging: central  =  plugging in identifiable bronchi; peripheral  =  centrilobular nodules and tree in bud.
Airway wall thickening: mild  =  >2 mm in hilum, 1 mm centrally and 0.5 mm peripherally.
*Scores for each abnormality were calculated according to Brody et al.19 Figure 1 shows images corresponding to the scoring system abnormalities.
    Central lung (extent)Absent<33%33–67%>67%
    Peripheral lung (extent)Absent<33%33–67%>67%
    Size of largestAbsentB <2 VB 2–3 VB >3 V
    Size of averageAbsentB <2 VB 2–3 VB >3 V
Mucus plugging
    Central (extent)Absent<33%33–67%>67%
    Peripheral (extent)Absent<33%33–67%>67%
Airway wall thickening
    SeverityAbsentMild0.5–1 V>1 V
    Central lung (extent)Absent<33%33–67%>67%
    Peripheral lung (extent)Absent<33%33–67%>67%
Consolidation (extent)Absent<33%33–67%>67%
Mosaic pattern (extent): inspiratory CT scan findingAbsent<33%33–67%>67%
Air trapping (extent): expiratory CT scan findingAbsent<33%33–67%>67%