Table 3.
Visual evaluation results.
| Image | n | Mean ± SEM | Median (Q1–Q3) | Wilcoxon signed rank p | Mean/Median of (DVA30-DSA100) Wilcoxon one sample p |
|---|---|---|---|---|---|
| Abdominal (n = 120) | |||||
| DVA100 | 30 | 3.67 ± 0.10 | 3.71 (3.43–4.00) | 0.003 | − 0.26 ± 0.12/ − 0.29 (− 0.54–0.25) 0.036 |
| DSA100 | 30 | 3.49 ± 0.10 | 3.57 (3.18–3.86) | ||
| DVA30 | 30 | 3.23 ± 0.10 | 3.29 (2.86–3.54) | 0.013 | |
| DSA30 | 30 | 3.00 ± 0.10 | 3.07 (2.86–3.29) | ||
| Abdominal, after exclusion of patients with excessive intestinal gases (n = 108) | |||||
| DVA100 | 27 | 3.63 ± 0.10 | 3.71 (3.36–4.00) | 0.002 | − 0.10 ± 0.09/ − 0.14 (− 0.43–0.29) 0.350 |
| DSA100 | 27 | 3.42 ± 0.10 | 3.43 (3.14–3.72) | ||
| DVA30 | 27 | 3.33 ± 0.09 | 3.31 (2.93–3.64) | 0.001 | |
| DSA30 | 27 | 3.02 ± 0.10 | 3.14 (2.86–3.36) | ||
| Femoral (n = 120) | |||||
| DVA100 | 30 | 4.32 ± 0.06 | 4.33 (4.21–4.50) | 0.390 | − 0.08 ± 0.06/0.00 (− 0.17–0.13) 0.435 |
| DSA100 | 30 | 4.27 ± 0.09 | 4.33 (3.88–4.67) | ||
| DVA30 | 30 | 4.19 ± 0.09 | 4.33 (3.88–4.63) | 0.020 | |
| DSA30 | 30 | 4.07 ± 0.11 | 4.33 (3.75–4.46) | ||
| Crural (n = 232) | |||||
| DVA100 | 58 | 3.99 ± 0.07 | 4.00 (3.71–4.29) | < 0.001 | 0.25 ± 0.07/0.21 (0.00–0.68) < 0.001 |
| DSA100 | 58 | 3.37 ± 0.08 | 3.43 (3.00–3.82) | ||
| DVA30 | 58 | 3.62 ± 0.09 | 3.71 (3.29–4.14) | < 0.001 | |
| DSA30 | 58 | 3.14 ± 0.09 | 3.29 (2.71–3.57) | ||
Readers evaluated in total 472 images by using a 5-grade Likert scale: ranging from poor (1) to outstanding (5) image quality (for details see The Materials and Methods section). Values are expressed as the mean ± SEM, and the median and the interquartile range (Q1–Q3). Data were analysed by the Wilcoxon signed rank test (DVA vs DSA) or the Wilcoxon one sample test (non-inferiority analysis between DVA30 and DSA100). Bold: significant difference, p < 0.05. DVA: Digital Variance Angiography, DSA: Digital Subtraction Angiography. The index defines the applied protocol, 100: normal dose, 30: low-dose. SEM: Standard Error of Mean.