Table 3.
Results of CT quantitative and qualitative parameters in the two study groups
| Group SDP (n=51) | Group LDP (n=48) | P | |
|---|---|---|---|
| CT quantitative image quality | |||
| SD at right renal cortex | 34.1±8.4 (23-78.7) | 29.4±6.8 (17-44.3) | 0.0024 |
| SD at psoas | 35.1±8.5 (23-69) | 32.3±9.1 (19-55.7) | 0.0582 |
| SD at ilium | 43.8±8.8 (25-73.7) | 36±8.1 (18-56.7) | <0.0001 |
| SD at air | 17.7±4.0 (9.7-33.3) | 14.4±2.6 (9.3-20.7) | <0.0001 |
| Visual CT image quality | |||
| Definition soft tissue at kidney level | 3.2±0.7 | 2.8±0.6 | 0.0016 |
| Definition soft tissue at kidney level (summed up 6 mm slice) | 3.1±0.6 | 3.2±0.6 | 0.508 |
| Definition bone axial slices | 3.2±0.6 | 3.4±0.6 | 0.032 |
| Definition bone sagittal and coronal slices | 2.3±0.5 | 3.1±0.6 | <0.0001 |
| Noise soft tissue at kidney level | 3.0 ±0.6 | 2.6±0.6 | 0.0038 |
| Noise soft tissue at kidney level (summed up 6 mm slice) | 3.5±0.5 | 3.4±0.6 | 0.4633 |
The CT quantitative image quality values in both groups are in mean ± SD with range in the parenthesis. The qualitative parameters are derived from consensus rating by two physicians and were scored from 1-4. Statistically significant p values are highlighted in bold text in the right hand column. SDP- Standard dose ‘old’ protocol group; LDP- Lower dose ‘new’ protocol group; SD-standard deviation.