Collaterals on ASL (presence of ATA) versus DSA-confirmed collaterals—nonatherosclerosis
| DSA | |||
|---|---|---|---|
| Yes | No | ||
| ASL | Yes | 48 | 50 |
| No | 9 | 25 | |
| P = .022 (χ2) | |||
| Sensitivity, 84.2% (78.0%–90.4%) | |||
| Specificity, 33.3% (25.3%–41.4%) | |||
| PPV, 49.0% (40.5%–57.5%) | |||
| NPV, 73.5% (66.0%–81.1%) | |||
Note:—PPV indicates positive predictive value; NPV, negative predictive value.