Table 3. The diagnostic performance of SWV and SWV ratio in differentiating benign from malignant thyroid nodules.
| Nodules | Method | Sensitivity% | Specificity% | PPV% | NPV% | Accuracy% | AUC |
| ≤10 mm | SWV | 68.2(15/22) | 74.9(17/23) | 71.4(15/21) | 70.8(17/24) | 71.1(32/45) | 0.707 |
| SWV ratio | 81.8(18/22) | 52.2(12/23) | 62.1(18/29) | 75(12/16) | 66.7(30/45) | 0.672 | |
| 11–20 mm | SWV | 94.1(16/17) | 70.7(29/41) | 57.1(16/28) | 96.7(29/30) | 77.6(45/58) | 0.879 |
| SWV ratio | 76.5(13/17) | 87.8(36/41) | 72.2(13/18) | 90(36/40) | 84.5(49/58) | 0.862 | |
| >20 mm | SWV | 100(5/5) | 84.6(55/65) | 33.3(5/15) | 100(55/55) | 85.7(60/70) | 0.940* |
| SWV ratio | 80(4/5) | 98.5(64/65) | 80(4/5) | 98.5(64/65) | 97.1(68/70) | 0.914** | |
| Total | SWV | 75(33/44) | 82.2(106/129) | 58.9(33/56) | 90.5(106/117) | 80.3(139/173) | 0.861 |
| SWV ratio | 63.6(28/44) | 88.4(114/129) | 65.1(28/43) | 87.7(114/130) | 82.1(142/173) | 0.831 |
*
Compared with AUC of SWV in nodule ≤10 mm, z = 2.73, P<0.01.
**
Compared with AUC of SWV ratio in nodule ≤10 mm, z = 2.30, P<0.05.