TABLE 2.
ROC Results of the ADC Values and Ki-67 Proliferation Index for Glioma Grading
| Variables | Cutoff | Sensitivity, % | Specificity, % | Accuracy, % | PPV, % | NPV, % | AUC |
|---|---|---|---|---|---|---|---|
| ADCmean | 1.187 ×10−3 mm2/s | 79.3 | 82.4 | 80.2 | 92.0 | 60.9 | 0.875 |
| ADCmin | 0.970 ×10−3 mm2/s | 86.2 | 94.1 | 88.4 | 97.4 | 72.7 | 0.946 |
| ADC ratio | 1.426 | 72.4 | 88.2 | 76.9 | 94.0 | 55.6 | 0.854 |
| Ki-67 | 7 | 94.1 | 89.7 | 90.9 | 97.5 | 78.0 | 0.962 |
ADC indicates apparent diffusion coefficient; ADC ratio, tumor/normal brain ADC ratio; ADCmean, mean apparent diffusion coefficient; ADCmin, minimum apparent diffusion coefficient; AUC, area under the curve; NPV, negative predictive value; PPV, positive predictive value; ROC, receiver operating characteristic.