FIGURE 1.

FIGURE 2.

FIGURE 3.

FIGURE 4.

FIGURE 5.

FIGURE 6.

Characteristics of the distribution of clinical data of patients among groups
| Clinical indicators | Training set (n = 265) | Validation set (n = 114) | External test set (n = 82) | Statistics | P value |
|---|---|---|---|---|---|
| Age (years) a | 43.0 (35.0–52.0) | 45.5 (35.3–54.0) | 45.0 (34.0–53.0) | 0.401 | 0.818 |
| Size (mm) a | 6.1 (4.7–7.8) | 5.6 (4.2–7.0) | 6.0 (4.6–7.3) | 4.090 | 0.129 |
| Aspect ratio a | 1.1 (0.9–1.3) | 1.0 (0.9–1.2) | 1.1 (0.9–1.3) | 3.547 | 0.170 |
| Sex | 1.493 | 0.474 | |||
| Male | 69 (26.0) | 24 (21.1) b | 23 (28.1) b | ||
| Female | 196 (74.0) | 90 (79.0) | 59 (72.0) | ||
| Location | 15.632 | 0.016 | |||
| Upper segment | 33 (12.5) | 15 (13.2) | 22 (26.8) b | ||
| Middle segment | 146 (55.1) | 58 (50.9) | 38 (46.3) | ||
| Lower segment | 57 (21.5) | 29 (25.4) | 20 (24.4) | ||
| Isthmus | 29 (10.9) | 12 (10.5) | 2 (2.4) | ||
| ETE | 4.733 | 0.094 | |||
| Absence | 226 (85.3) | 102 (89.5) | 77 (93.9) | ||
| Presence | 39 (14.7) | 12 (10.5) | 5 (6.1) | ||
| Echogenicity | 4.110 | 0.391 | |||
| Hyperechoic/isoechoic | 11 (4.2) | 8 (7.0) | 5 (6.1)b | ||
| Hypoechoic | 200 (75.5) | 75 (65.8) | 59 (72.0) | ||
| Markedly | |||||
| Hypoechoic | 54 (20.3) | 31 (27.2) | 18 (22.0) | ||
| Margin | 2.449 | 0.294 | |||
| Clear | 113 (42.6) | 53 (46.5) | 29 (35.4) | ||
| Unclear | 152 (57.4) | 61 (53.5) | 53 (64.6) | ||
| Shape | 5.242 | 0.073 | |||
| Regular | 115 (43.4) | 47 (41.2) | 24 (29.3) | ||
| Irregular | 150 (56.6) | 67 (58.8) | 58 (70.7) | ||
| Vascularity | 5.642 | 0.465 | |||
| Type I | 95 (35.9) | 38 (33.3) | 24 (29.3) | ||
| Type II | 21 (7.9) | 9 (7.9) | 12 (14.6) | ||
| Type III | 140 (52.8) | 63 (55.3) | 41 (50.0) | ||
| Type IV | 9 (3.4) | 4 (3.5) | 5 (6.1) | ||
| Calcification Absence | 123 (46.4) b | 58 (50.9) | 41 (50.0) | 2.902 | 0.821 |
| Microcalcification | 100 (37.7) | 38 (33.3) | 25 (30.5) | ||
| Coarse type | 25 (9.4) | 13 (11.4) | 10 (12.2) | ||
| Mixed type | 17 (6.4) | 5 (4.4) | 6 (7.3) | ||
| CC | 0.212 | 0.900 | |||
| Absence | 97 (36.6) | 41 (36.0) | 32 (39.0) | ||
| Presence | 168 (63.4) | 73 (64.0) | 50 (61.0) | ||
| DC | 0.496 | 0.780 | |||
| Absence | 186 (70.2) | 83 (72.8) | 56 (68.3) | ||
| Presence | 79 (29.8) | 31 (27.2) | 26 (31.7) | ||