Image noise by tube current and body AP diameter
| Number | Mean Image Noise (HU) | P Value | |
|---|---|---|---|
| Tube current (mA) | .25 | ||
| Low (≤40) | 25 | 84 (38) | |
| Medium (40–80) | 35 | 69 (41) | |
| High (>80) | 17 | 69 (25) | |
| AP diameter (cm) | .009 | ||
| Large (>30) | 17 | 92 (43) | |
| Medium (20–30) | 56 | 71 (34) | |
| Small (<20) | 4 | 33 (11) |
Note:—ANOVA was used to evaluate differences in image noise in categories of tube current and body AP diameter. Numbers in parentheses are standard deviations. HU indicates Hounsfield unit.