Table 3.
Apparent lung volumes before and after injection of contrast material in the two groups of patients
| Patients | Before injection | After injection | P value |
| Group 1 (30 s after injection) | |||
| Total volume (ml) | 2546 ± 914 | 2542 ± 909 | NS |
| Volume of gas (ml) | 1444 ± 849 | 1358 ± 794 | 0.03 |
| Volume of tissue (ml) | 1105 ± 235 | 1193 ± 245 | 0.02 |
| Group 2 (15 min after injection) | |||
| Total volume (ml) | 2801 ± 882 | 2826 ± 833 | NS |
| Volume of gas (ml) | 1415 ± 853 | 1337 ± 838 | 0.02 |
| Volume of tissue (ml) | 1386 ± 109 | 1488 ± 157 | 0.01 |
The two-way analysis of variance for one within factor (before and after injection of contrast material) and one grouping factor (group 1 and group 2) showed an absence of interaction between the two groups.