Table 1. Radiation dose (CTDIvol, DLP), manually (scan length, table height) or automatically (tube current, mean mAs) adjusted scan parameters as well as the maximal effective abdominal diameter as surrogate for patient’s weight of the 3 CT follow-up examinations each composed of a non-contrast-enhanced scan of the liver and a contrast-enhanced scan of the chest and abdomen in 60 patients.
| Contrast-enhanced CT of the chest | Non-enhanced CT of the liver | Contrast-enhanced CT of the abdomen | |
|---|---|---|---|
| Number of examinations (n) | 180 | 180 | 180 |
| CTDIvol [mGy] | |||
| Median: | 5.9 | 8.1 | 7.7 |
| 95% CI for the median: | 5.4 to 6.4 | 7.6 to 8.9 | 7.1 to 8.2 |
| IQR: | 2.4 | 4.3 | 3.1 |
| DLP [mGy*cm] | |||
| Median: | 226.0 | 183.0 | 363.5 |
| 95% CI for the median: | 207.2 to 241.0 | 173.4 to 197.6 | 329.7 to 394.0 |
| IQR: | 130.0 | 108.5 | 180.5 |
| Scan length [cm] | |||
| Mean: | 39.1 | 22.8 | 48.2 |
| 95% CI for the mean: | 38.3 to 39.9 | 22.3 to 23.2 | 47.6 to 48.7 |
| SD: | 5.5 | 3.0 | 3.8 |
| Table height [cm] | |||
| Mean: | 16.2 | 16.2 | 16.2 |
| 95% CI for the mean: | 15.9 to 16.5 | 15.9 to 16.5 | 15.9 to 16.5 |
| SD: | 1.9 | 1.9 | 1.9 |
| Tube voltage | |||
| 80 kV (n) | 1 | 0 | 0 |
| 100 kV (n) | 168 | 38 | 179 |
| 120 kV (n) | 11 | 111 | 1 |
| 140 kV (n) | 0 | 31 | 0 |
| Mean mAs | |||
| Median: | 80.5 | 81.5 | 114.3 |
| 95% CI for the median: | 75.8 to 86.7 | 78.6 to 83.5 | 105.8 to 119.9 |
| IQR: | 35.7 | 23.3 | 45.9 |
| Max. effective diameter [cm] | |||
| Mean: | 32.2 | 32.2 | 32.2 |
| 95% CI for the mean: | 31.6 to 32.7 | 31.6 to 32.7 | 31.6 to 32.7 |
| SD: | 3.6 | 3.6 | 3.6 |
Abbreviations: CTDIvol = volume computed tomography dose index, DLP = dose-length-product, CI = confidence interval, IQR = interquartile range, SD = standard deviation.