Table 3—

Airway narrowing in normal and asthmatic subjects

Subject numberSlopeR2VarΔAi mmNumber of airwaysRepAi mmNumber of airways
10.710.920.6615
20.820.780.65160.3710
30.890.860.6614
40.780.770.4025
50.990.890.27110.3924
60.940.840.3622
70.890.740.837
80.630.700.609
90.600.460.70110.5830
100.770.830.50140.4711
110.3411
120.4213
130.1611
140.741.000.394
150.950.840.5521
160.740.920.6421
170.910.840.2713
181.040.940.8314
190.960.880.5713
201.050.920.8213
  • The magnitude of airway narrowing that occurred following methacholine challenge, measured by the slope of √airway lumen area (√Ai) (baseline) versus √Ai (post)

  • VarΔAi: heterogeneity of narrowing measured by the variability in narrowing from pre versus postmethacholine scans

  • RepAi: the coefficient of repeatability of Ai measurements calculated from repeat scans