Table 5. Diagnostic Performance of Radiography and WBCT for Visualizing Subchondral Cysts by Surface {95% CI}.
| Modality and Location | Prevalence | Sensitivity* | Specificity* | Accuracy* | PPV* | NPV* |
|---|---|---|---|---|---|---|
| Radiography | ||||||
| Medial femur | 0/40 (0%) | 100% | 100% | 92.5% | - | 92.5% |
| Medial tibia | 1/40 (2.5%) | 25.0% | 100% | 92.5% | 100% | 92.3% |
| Lateral femur | 0/40 (0%) | 100% | 100% | 97.5% | - | 97.5% |
| Lateral tibia | 0/40 (0%) | 100% | 100% | 95.0% | - | 95.0% |
| WBCT | ||||||
| Medial femur | 3/40 (7.5%) | 100% | 100% | 100% | 100% | 100% |
| Medial tibia | 4/40 (10.0%) | 100% | 100% | 100% | 100% | 100% |
| Lateral femur | 2/40 (5.0%) | 100% | 97.4% | 97.5% | 50.0% | 100% |
| Lateral tibia | 3/40 (7.5%) | 100% | 97.4% | 97.5% | 66.7% | 100% |
*
Where p-values could be calculated, there were no statistically significant differences between radiograph and WBCT; MRI prevalences were 3/40, 4/40, 1/40 and 2/40 for the medial femur, medial tibia, lateral femur and lateral tibia respectively.