Threshold values for Cho/Cr ratio for differentiation between low- and high-grade gliomas
| Description | Cho/Cr | Sensitivity | Specificity | PPV | NPV | C2 Error | C1 Error |
|---|---|---|---|---|---|---|---|
| Minimum C2 Error* | 1.08 | 97.5 | 12.5 | 77.0 | 62.5 | 23.8 | 45.0 |
| Minimum C1 Error† | 1.56 | 75.8 | 47.5 | 81.2 | 39.6 | 31.3 | 38.3 |
| Same sensitivity as cMRI | 1.61 | 72.5 | 50.0 | 81.3 | 37.7 | 33.1 | 38.8 |
| Same specificity as cMRI | 1.88 | 55.0 | 65.0 | 83.5 | 33.3 | 41.9 | 38.8 |
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.