Table 2.
Pulmonary arterial computed tomography attenuations before and after injection of contrast material in the two groups of patients
| Patient no | Mean CT attenuation before injection (HU) | Mean CT attenuation after injection (HU) | Pulmonary concentration of contrast material (%) |
| Group 1 (30 s after injection) | |||
| 1 | 31 | 245 | 1.9 |
| 2 | 45 | 218 | 1.8 |
| 3 | 49 | 110 | 0.3 |
| 4 | 49 | 169 | 1.2 |
| 5 | 36 | 265 | 2 |
| 6 | 43 | 146 | 0.7 |
| 7 | 46 | 219 | 1.4 |
| Mean ± SD | 43 ± 7 | 196 ± 56 | 1.3 ± 0.8 |
| Group 2 (15 min after injection) | |||
| 8 | 43 | 83 | 0.005 |
| 9 | 62 | 67 | 0 |
| 10 | 25 | 60 | 0 |
| 11 | 21 | 60 | 0 |
| 12 | 39 | 55 | 0 |
| 13 | 65 | 75 | 0 |
| 14 | 30 | 72 | 0.07 |
| Mean ± SD | 41 ± 17 | 67 ± 10 | 0.02 ± 0.002 |
CT, computed tomography; HU, Hounsfield units.