Table 3. Receiver operating characteristic curves for quantitative and qualitative parameters in the differentiation between benign and malignant lesions.
| Variables | Cut-off value | Sensitivity (%) | Specificity (%) | Accuracy (%) | PPV (%) | NPV (%) | AUROC | 95%CI | P | |
|---|---|---|---|---|---|---|---|---|---|---|
| Emean | kPa | 36.05 | 85.1 (40/47) | 96.6 (172/178) | 94.2 (212/225) | 87.0 (40/46) | 96.1 (172/179) | 0.943 | 0.896–0.990 | <0.001 |
| m/s | 3.30 | 85.1 (40/47) | 95.5 (170/178) | 93.3 (210/225) | 83.3 (40/48) | 96.0 (170/177) | 0.931 | 0.882–0.981 | <0.001 | |
| ESD | kPa | 17.90 | 93.6·(44/47) | 97.8· (174/178) | 96.9· (218/225) | 91.7· (44/48) | 98.3· (174/177) | 0.936 | 0.866–1.000 | <0.001 |
| m/s | 0.91 | 93.6 (44/47) | 95.5 (170/178) | 95.1 (214/225) | 84.6 (44/52) | 98.3 (170/173) | 0.936 | 0.866–1.000 | <0.001 | |
| Eratio | kPa | 3.67 | 76.6 (36/47) | 91.0 (162/178) | 88.0 (198/225) | 69.2 (36/52) | 93.6 (162/173) | 0.872 | 0.809–0.936 | <0.001 |
| m/s | 1.87 | 76.6 (36/47) | 91.0 (162/178) | 88.0 (198/225) | 69.2 (36/52) | 93.6 (162/173) | 0.863* | 0.794–0.932 | <0.001 | |
| Color pattern | 2–3 | 89.4 (42/47) | 97.2 (173/178) | 95.6 (215/225) | 89.4 (42/47) | 97.2 (173/178) | 0.957 | 0.914–1.000 | <0.001 |
Emean = the mean elasticity; ESD = standard deviation of the elasticity; Eratio = the ratio elasticity; PPV = positive predictive value; NPV = negative predictive value; CI = confidence interval; AUROC = area under the receiver operating characteristic curve.
*There are statistically significant difference between AUROC of color patterns and Eratio in speed mode (P = 0.03 < 0.05).
·ESD expressed in KPa obtained the highest Sensitivity, Specificity, Accuracy, PPV, NPV compared with the Eratio with statistically significant difference. (Corresponding P = 0.008 for Sensitivity comparison, P = 0.002 for Specificity comparison, P = 0.000 for Accuracy comparison, P = 0.006 for PPV comparison, P = 0.030 for NPV comparison, all P < 0.05).