Threshold values for rCBV for differentiation between low- and high-grade gliomas
| Description | rCBV | Sensitivity | Specificity | PPV | NPV | C2 Error | C1 Error |
|---|---|---|---|---|---|---|---|
| Minimum C2 Error* | 1.75 | 95.0 | 57.5 | 87.0 | 79.3 | 14.4 | 23.8 |
| Minimum C1 Error† | 2.97 | 72.5 | 87.5 | 94.6 | 51.5 | 23.8 | 20.0 |
| Same sensitivity as cMRI | 2.97 | 72.5 | 87.5 | 94.6 | 51.5 | 23.8 | 20.0 |
| Same specificity as cMRI | 2.18 | 87.5 | 65.0 | 88.2 | 63.4 | 18.1 | 23.0 |
Note.—Conventional MR imaging (cMRI) sensitivity 72.5%, specificity 65.0%, PPV 86.1%, NPV 44.1%, C2 error 29.4%, and C1 error 31.8%.
* C2 = the percentage of observed data points misclassified.
† C1 = 1 − (sensitivity + specificity)/2. This maximizes the average of sensitivity and specificity.