Table 3.
Comparison of the ratio of upright PFT volumes to supine CT volumes and AV, TV, and TV difference from supine CT between normal subjects and severe asthmatics
| Normal Subjects | Severe Asthmatics | P (From t-Test) | |
|---|---|---|---|
| TLVTLC (CT)/TLC (PFT) × 100 | 91 ± 2 | 91 ± 2 | 0.98 |
| TLVFRC (CT)/FRC (PFT) × 100 | 88 ± 3 | 89 ± 3 | 0.76 |
| supAVTLC (CT)/TLC (PFT) × 100 | 76 ± 2 | 76 ± 2 | 0.98 |
| AVFRC (CT)/FRC (PFT) × 100 | 58 ± 4 | 64 ± 2 | 0.23 |
| IC (CT)/IC (PFT) × 100 | 94 ± 7 | 92 ± 4 | 0.85 |
| AVTLC, liters | 4.14 ± 0.2 | 4.27 ± 0.2 | 0.66 |
| AVFRC, liters | 1.57 ± 0.1 | 1.95 ± 0.1 | 0.06 |
| TVTLC, liters | 0.79 ± 0.04 | 0.79 ± 0.03 | 0.96 |
| TVFRC, liters | 0.76 ± 0.04 | 0.75 ± 0.02 | 0.70 |
| (∣TVTLC − TVFRC∣/TVTLC) × 100 | 6 ± 1 | 6 ± 1 | 0.72 |
Values are means ± SE. CT, computed tomography; TLV, total lung volume (air + tissue); AV, air volume; TV tissue volume; IC, inspiratory capacity. PFT volumes (TLC, FRC, and IC) of 1 normal subject and 1 severely asthmatic subject were not available.