Table 3. Diagnostic performances of B-mode US and B-mode US combined with SWE.
| Parameter | Threshold* | AUC | p value# | Sensitivity | Specificity | p value* | PPV | NPV |
|---|---|---|---|---|---|---|---|---|
| B-mode US categorya | >4a | 0.9064 | NA | 67/73 (91.78) | 110/137 (80.29) | NA | 67/94 (71.28) | 110/116 (94.83) |
| +2D SWE | ||||||||
| ESDU | >10.73 | 0.9571 | 0.0005 | 63/73 (86.30) | 130/137 (94.89) | 0.0002 | 63/70 (90.00) | 130/140 (92.86) |
| ESDE | >13.4 | 0.9683 | 0.0003 | 66/73 (90.41) | 132/137 (96.35) | <0.0001 | 66/71 (92.96) | 132/139 (94.96) |
| Emax | >80.8 | 0.9767 | <0.0001 | 65/73 (89.04) | 132/137 (96.35) | <0.0001 | 65/70 (92.86) | 132/140 (94.29) |
| +3D SWE | ||||||||
| ESDU | >10.23 | 0.9454 | 0.0007 | 60/73 (82.19) | 129/137 (94.16) | 0.0006 | 60/68 (88.24) | 129/142 (90.85) |
| ESDE | >13 | 0.9563 | 0.0007 | 62/73 (84.93) | 131/137 (95.62) | <0.0001 | 62/68 (91.18) | 131/142 (92.25) |
| Emax | >131.7 | 0.9562 | 0.0016 | 66/73 (90.41) | 122/137 (89.05) | 0.0442 | 66/81 (81.48) | 122/129 (94.57) |
aB-mode US category was defined according to the BI-RADS classification for US. NA = not available. The + before 2D and 3D SWE indicates the effect of adding that SWE feature to the original BI-RADS category 4a and 4b masses. #p value of testing the null hypothesis that there is no change in AUC with the addition of the SWE feature (McNemar test). *p value of testing the null hypothesis that there is no change in specificity with the addition of the SWE feature (McNemar test). *Threshold as the optimal cut off, yielding the maximal sum of the sensitivity and specificity.