Sensitivity, specificity, accuracy, and interobserver agreement in detecting stroke
| Imaging Study | True-Positive | False-Positive | False-Negative | True-Negative | Sensitivity (%) | Specificity (%) | Accuracy (%) | κ |
|---|---|---|---|---|---|---|---|---|
| Nonenhanced CT | ||||||||
| Any sign | 18 | 23 | 8 | 43 | 69.2 | 65.0 | 66.2 | 0.502 |
| Lost cortical ribbon | 11 | 5 | 15 | 61 | 43.4 | 92.3 | 78.5 | 0.528 |
| Lost insular ribbon | 7 | 3 | 19 | 63 | 26.9 | 95.0 | 75.8 | 0.591 |
| Basal ganglia hypodensity | 15 | 10 | 12 | 56 | 55.8 | 85.0 | 76.7 | 0.478 |
| Dense artery | 6 | 10 | 20 | 56 | 23.1 | 85.0 | 67.5 | 0.462 |
| ATLANTIS/ASPECTS hypoattenuations | 115 | 77 | 139 | 1141 | 45.2 | 93.7 | 85.3 | 0.594 |
| PCT | ||||||||
| TTP review | 194 | 298 | 60 | 920 | 76.5* | 75.6 | 75.7* | 0.526 |
| MTT review | 197 | 288 | 57 | 930 | 77.6* | 76.3 | 76.5* | 0.618 |
| rCBF review | 158 | 111 | 96 | 1107 | 62.2 | 90.9* | 86.0* | 0.516 |
| rCBV review | 128 | 89 | 126 | 1129 | 50.5 | 92.7* | 85.4* | 0.505 |
| Computerized automated method | 173 | 94 | 81 | 1124 | 68.2 | 92.3* | 88.1* | NA |
Note.—Follow-up CT or MR imaging was the criterion standard. Globally, accuracy was significantly greater with PCT than with nonenhanced CT: TTP and MTT maps are significantly more sensitive, whereas rCBF and rCBV maps were significantly more specific. NA indicates not applicable.
* Significantly superior to nonenhanced CT (any sign).