| Internal enhancement | Benign | Malignant | Total | p value |
| Homogenous | 1 | 4 | 5 | p < 0.001 |
| Heterogeneous | 2 | 37 | 39 | |
| Rim | 4 | 1 | 5 | |
| Dark internal septation | 0 | 0 | 0 | |
| Total | 0 | 0 | 49 |