Table S1.
Relationship between different US features and malignant histopathologic results based on stepwise backward logistic regression analysis
| Sonographic features | Malignancy rate (%) | Stepwise backward LR | |
|---|---|---|---|
|
| |||
| OR (95% CI) | p | ||
| Long diameter | N/A | 1.05 (1.02–1.07) | 0.001 |
|
| |||
| Composition* | |||
| Mixed | 5/41 (12) | ||
| Solid | 57/206 (28) | ||
|
| |||
| Echogenicity* | 5.54 (2.44–12.56) | <0.001 | |
| Isoechoic | 22/176 (13) | ||
| Hypoechoic | 40/71 (56) | ||
|
| |||
| Shape | |||
| Wider-than-tall | 45/228 (20) | ||
| Taller-than-wide | 17/19 (90) | ||
|
| |||
| Borders | 64.68 (13.25–315.68) | <0.001 | |
| Regular | 33/216 (15) | ||
| Irregular | 29/31 (94) | ||
|
| |||
| Punctuate echogenic foci | |||
| Absent | 43/189 (23) | ||
| Present | 19/58 (33) | ||
|
| |||
| Macrocalcification | |||
| Absent | 54/228 (24) | ||
| Present | 8/19 (42) | ||
|
| |||
| Microcalcification | |||
| Absent | 51/233 (22) | ||
| Present | 11/14 (79) | ||
|
| |||
| Colloid crystal | 2.63 (0.82–8.42) | 0.10 | |
| Absent | 56/206 (27) | ||
| Present | 6/41 (15) | ||
US, ultrasonography; LR, logistic regression; OR, odds ratio; 95% CI, confidence interval; N/A, non-applicable.
Model p value ≤0.001 (Omnibus test). Cox & Snell R2 = 0.351; Nagelkerke R2 = 0.519.
*
Due to their extensively limited numbers, two cystic, one spongiform, and one hyperechoic solid nodules were excluded from the logistic regression analyses, while all hypoechoic nodules, including mild and marked hypoechoic ones, were analyzed together in a single group.