Accuracy, sensitivity, specificity, NPV, and PPV of the different imaging techniques for the diagnosis of vasospasm requiring endovascular treatment
| Endovascular Treatment or Not | DSA Gold Standard | TCD Absolute FV (cm/s) | TCD EICA Ratios | CTA | PCT rCBV (cc × 100 g−1) | PCT rCBF (cc × 100 g−1 × min−1) | PCT MTT (s) | PCT TTP (s) | PCT MTT + CTA |
|---|---|---|---|---|---|---|---|---|---|
| Thresholds | >180 | >6.00 | Presence or Absence of Severe | <4.3 | <39.3 | >7.6 | >26.8 | ||
| TN | 570 | 501 | 532 | 549 | 314 | 560 | 499 | 561 | 487 |
| FP | 0 | 69 | 38 | 21 | 256 | 10 | 71 | 10 | 83 |
| FN | 0 | 48 | 54 | 28 | 34 | 23 | 18 | 33 | 25 |
| TP | 60 | 12 | 6 | 32 | 26 | 37 | 42 | 27 | 35 |
| Accuracy | 100.0% | 81.4% | 85.4% | 92.2% | 54.0% | 94.8% | 85.9% | 93.2% | 82.9% |
| Sensitivity | 100.0% | 20.0% | 10.0% | 53.3% | 43.3% | 61.7% | 70.0% | 45.0% | 58.3% |
| Specificity | 100.0% | 87.9% | 93.3% | 96.3% | 55.1% | 98.2% | 87.5% | 98.2% | 85.4% |
| NPV | 100.0% | 91.3% | 90.8% | 95.1% | 90.2% | 96.1% | 96.5% | 94.4% | 95.1% |
| PPV | 100.0% | 14.8% | 13.6% | 60.4% | 9.2% | 78.7% | 37.2% | 73.0% | 29.7% |
Note:— MTT was again the parameter with the highest NPV, but with this time a threshold at 7.6 s, whereas PCT rCBF with a threshold at 39.3 cc × 100 g−1 × min−1 was the most accurate indicator for endovascular therapy. FV indicates flow velocity; EICA, extracranial to intracranial; rCBV, relative cerebral blood volume; rCBF, relative cerebral blood flow; MTT, mean transit time; TTP, time-to-peak; TP, true-positives; FP, false-positives; FN, false-negatives; TP, true-positives; NPV, negative predictive value; PPV, positive predictive value.