Table 3.
Agreement between the grades detected according to K&L scale of CR and the proposed ultrasonography in patients with KOA.
| OSTEOPHYTES GRADES BY US | OSTEOPHYTES GRADES BY CR | SENSITIVITY OF US* | SPECIFICITY OF US* | PPV | NPV | NLR | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | TOTAL SENSITIVITY: 95% | TOTAL SPECIFICITY: 95% | TOTAL PPV 95% | TOTAL NPV 95% | TOTAL NLR 0.05 | ||
| 0 | 16 | 2 | 0 | 0 | 0 | 94.1% | 98.8% | 88.9% | 99.4% | 0.06 | |
| 1 | 1 | 26 | 0 | 0 | 0 | 92.9% | 99.3% | 96.3% | 98.7% | 0.07 | |
| 2 | 2A | 0 | 0 | 29 | 0 | 0 | 93.6% | 100% | 100% | 98.4% | 0.06 |
| 2B | 0 | 0 | 22 | 0 | 0 | 91.6% | 100% | 100% | 98.5% | 0.08 | |
| 3 | 0 | 0 | 2 | 44 | 3 | 88.2% | 96.3% | 89.8% | 99.2% | 0.02 | |
| 4 | 0 | 0 | 0 | 1 | 34 | 91.9% | 99.3% | 97.1% | 97.9% | 0.08 | |
Note:
*
Sensitivity of US with the reference being the K&L grading of CR.
Abbreviations: CR, conventional radiography; US, ultrasound; PPV, positive predictive values; NPV; negative predictive values; NLR, Negative likelihood ratio.