Table 2.
The statistical properties of %Utotal, %Uarea, and %Ushape in asthmatic and nonasthmatic subjects computed from 3 scans: baseline at MTLV, post- MCh at MTLV, and post-MCh at TLC
| Asthmatic | Nonasthmatic | |
|---|---|---|
| %Utotal | ||
| BM | 5.61% ± 5.50 (0.58–32.37%) | 5.48% ± 5.79 (0.77–33.06%) |
| MM | 5.81% ± 5.15 (0.67–29.54%) | 5.73% ± 6.84 (0.53–39.45%) |
| MT | 4.55% ± 5.90 (0.45–52.99%) | 4.87% ± 5.34 (0.44–35.88%) |
| %Uarea | ||
| BM | 1.53% ± 4.39 (0.02–28.38%) | 1.33% ± 4.43 (0.02–26.36%) |
| MM | 1.55% ± 3.78 (0.22–36%) | 1.37% ± 5.67 (0.33–22%) |
| MT | 1.23% ± 3.76 (0.01–24.97%) | 1.09% ± 4.02 (0.02–28.86%) |
| %Ushape | ||
| BM | 3.17% ± 3.00 (0.31–21.91%) | 3.29% ± 3.20 (0.50–21.15%) |
| MM | 3.01% ± 3.08 (0.36–28.22%) | 3.20% ± 3.27 (0.49–20.79%) |
| MT | 2.48% ± 4.15 (0.31–51.09%) | 2.66% ± 2.99 (0.22–21.18%) |
Values shown are medians ± SD with range in parentheses. %Utotal, total underestimation of airway resistance due to ignoring the longitudinal heterogeneity; %Uarea, the contribution to %Utotal caused by longitudinal heterogeneity in the airway cross-sectional area; %Ushape, the contribution to %Utotal caused by a noncircular shape; BM, baseline scan at mid-tidal lung volume (MTLV); MM, post-MCh scan at MTLV; MT, post-MCh scan at total lung capacity (TLC).