Table 1.
Conventional US characteristics of thyroid nodules.
| Characteristics | Benign | Malignant |
|---|---|---|
| Nodules (n = 356) | 84 | 272 |
| Maximum diameter | ||
| ≤ 1 cm | 44 | 176 |
| 1–2 cm | 23 | 68 |
| ≥ 2 cm | 17 | 28 |
| Location | ||
| Superior pole | 7 | 56 |
| Middle | 53 | 124 |
| Inferior pole | 24 | 96 |
| Aspect ratio | ||
| > 1 | 6 | 166 |
| < 1 | 78 | 106 |
| Echogenicity | ||
| Hypoechoic | 29 | 258 |
| Isoechoic or Mixed echoic | 55 | 14 |
| Calcification | ||
| None | 69 | 124 |
| Microcalcification | 10 | 120 |
| Macrocalcification | 5 | 28 |
| Color Doppler character* | ||
| Absent vascularity | 32 | 137 |
| Minimal vascularity | 17 | 82 |
| Moderate vascularity | 20 | 35 |
| Marked vascularity | 15 | 18 |
*Color Doppler character was graded to be absent, minimal, moderate and marked. Absent vascularity: no vessel; minimal vascularity: point strip blood flow at 1–2 points, and the diameter of vessel was less than 1 mm; moderate vascularity: one vessel which diameter exceeded the radius of the lesion, or 3–4 point strip blood flow; marked vascularity: more than 4 vessels.