Validity statistics of near occlusion single-variable test models (in order of decreasing accuracy)
| Sensitivity | Specificity | PPV | NPV | |
|---|---|---|---|---|
| dlCA:dlCA* (≤0.87), n = 216 | 97.3 | 89.4 | 65.5 | 99.4 |
| dlCA (≤3.5 mm), n = 240 | 95.2 | 89.9 | 66.7 | 98.9 |
| dlCA:ECA (≤1.27), n = 231 | 90.5 | 87.3 | 61.3 | 97.6 |
| ICA (≤1.3 mm), n = 179 | 90.2 | 84.1 | 62.7 | 96.7 |
Note: —dlCA:dlCA* indicates ratio of the distal internal carotid artery (ICA) diameter to that of the contralateral distal ICA; dlCA, diameter of the distal ICA; dlCA:ECA, ratio of the distal ICA diameter to the distal external carotid artery diameter; ICA, narrowest diameter of the ICA bulb stenosis. All diameters are expressed in millimeters. PPV indicates positive predictive value; NPV, negative predictive value. Values demonstrate the ability of each model to identify near occlusion stenosis, based on threshold values for each model. The threshold values were based on the model’s receiver operating characteristic curve and assigned to maximize sensitivity and specificity for each test model. Positive and negative predictive values were calculated for all data. The threshold values (in parentheses) are reported under the model title, along with the population size (n).