Test characteristics of CTA findings
| CTA Finding | Sensitivity (%) | 95% CI | Specificity (%) | 95% CI | PPV (%) | 95% CI | NPV (%) | 95% CI |
|---|---|---|---|---|---|---|---|---|
| Asymmetrically increased arterial feeders | 86 | 42–99 | 100 | 52–100 | 100 | 56–100 | 88 | 67–88 |
| Asymmetrically increased venous collaterals | 42 | 11–79 | 71 | 30–95 | 60 | 17–93 | 56 | 38–70 |
| Transcalvarial channels | 29 | 5–70 | 86 | 42–99 | 67 | 12–98 | 55 | 43–62 |
| Shaggy sinus or tentorium | 42 | 11–79 | 100 | 56–100 | 100 | 31–100 | 64 | 55–64 |
| Prominent cortical venous drainage | 29 | 5–70 | 71 | 30–95 | 50 | 9–90 | 50 | 35–63 |