Effect of size on transcranial power Doppler detection of aneurysms
| Size (mm) | DSA | Power Doppler |
| 2–3.9 | 38 | 11 (29) |
| 4–5.9 | 49 | 13 (27) |
| 6–7.9 | 44 | 20 (45) |
| 8–9.9 | 14 | 7 (50) |
| 10–11.9 | 10 | 7 (70) |
| 12–13.9 | 1 | 1 (100) |
| 14–15.9 | 6 | 4 (67) |
| 16–17.9 | 2 | 2 (100) |
| 18–19.9 | 0 | 0 |
| 20–21.9 | 1 | 0 |
| 22–23.9 | 1 | 1 (100) |
| 24–25.9 | 2 | 1 (50) |
| Total | 168 | 67 (40) |
Numbers in parentheses represent percentage of aneurysms seen by transcranial power Doppler.