Table 2.
Qualitative and quantitative evaluation CT features in each cohort
| Training and internal validation cohorts (n = 140) | External validation cohort (n = 28) | |||||
|---|---|---|---|---|---|---|
| Pancreatobiliary type (n = 100) | Intestinal type (n = 40) | P value | Pancreatobiliary type (n = 18) | Intestinal type (n = 10) | P value | |
| Qualitative radiological features n (%) | ||||||
| Presence of ampullary mass | 69 (69.0) | 38 (95.0) | 0.001 | 15 (83.3) | 6 (60.0) | 0.172 |
| Growth pattern | < 0.001 | 0.129 | ||||
| Intrinsic | 15 (15.0) | 31 (77.5) | 8 (44.4) | 7 (70.0) | ||
| Mixed | 34 (34.0) | 2 (5.0) | 6 (33.3) | 3 (30.0) | ||
| Extrinsic | 51 (51.0) | 7 (17.5) | 4 (22.2) | 0 (0.0) | ||
| Presence of bulging ampulla | 42 (42.0) | 34 (85.0) | < 0.001 | 7 (38.9) | 6 (60.0) | 0.283 |
| Shape of distal CBD margin | < 0.001 | 0.094 | ||||
| Smooth | 48 (48.0) | 34 (85.0) | 5 (27.8) | 6 (60.0) | ||
| Irregular | 52 (52.0) | 6 (15.0) | 13 (72.2) | 4 (40.0) | ||
| Symmetry of distal CBD lumen | 0.001 | 0.046 | ||||
| Symmetric | 48 (48.0) | 31 (77.5) | 4 (22.2) | 6 (60.0) | ||
| Asymmetric | 52 (52.0) | 9 (22.5) | 14 (77.8) | 4 (40.0) | ||
| Pattern of distal CBD narrowing | 0.219 | 0.454 | ||||
| Gradual tapering | 54 (54.0) | 17 (42.5) | 6 (33.3) | 2 (20.0) | ||
| Abrupt narrowing | 46 (46.0) | 23 (57.5) | 12 (66.7) | 8 (80.0) | ||
| Pattern of biliary dilatation | 0.856 | 0.649 | ||||
| Central | 26 (26.0) | 11 (27.5) | 4 (22.2) | 3 (30.0) | ||
| Proportional | 74 (74.0) | 29 (72.5) | 14 (77.8) | 7 (70.0) | ||
| Presence of IHD dilatation | 95 (95.0) | 36 (90.0) | 0.276 | 18 (100.0) | 10 (100. 0) | 1.000 |
| IHD dilatation extent | 0.056 | 0.318 | ||||
| No dilation or mild dilation | 35 (35.0) | 21 (52.5) | 4 (22.2) | 4 (40.0) | ||
| Moderate to severe dilation | 65 (65.0) | 19 (47.5) | 14 (77.8) | 6 (60.0) | ||
| Presence of thickened distal CBD wall | 52 (52.0) | 9 (22.5) | 0.001 | 13 (72.2) | 4 (40.0) | 0.094 |
| Presence of dilated MPD | 53 (53.0) | 21 (52.5) | 0.957 | 8 (44.4) | 8 (80.0) | 0.069 |
| Peripancreatic lymph node enlargement | 13 (13.0) | 4 (10.0) | 0.623 | 1 (5.6) | 2 (20.0) | 0.236 |
| Necrosis, calcification, or cystic within lesion | 18 (18.0) | 1 (2.5) | 0.016 | 2 (11.1) | 0 (0) | 0.308 |
| Enhancement degree of lesion | < 0.001 | 0.050 | ||||
| Similar to the duodenum | 29 (29.0) | 29 (72.5) | 4 (22.2) | 7(70.0) | ||
| Non-similar to the duodenum | 67 (67.0) | 9 (22.5) | 14 (77.8) | 2(20.0) | ||
| Target-like enhancement | 4 (4.0) | 2 (5.0) | 0 (0) | 1 (10.0) | ||
| Peak enhancement phase of lesion | < 0.001 | 0.015 | ||||
| Arterial phase | 9 (9.0) | 6 (15.0) | 0 (0) | 3 (30.0) | ||
| Portal venous phase | 51 (51.0) | 31 (77.5) | 5 (27.8) | 4 (40.0) | ||
| Delayed phase | 40 (40.0) | 3 (7.5) | 13 (72.2) | 3 (30.0) | ||
| Main vascular involvement | 12 (12.0) | 0 (0) | 0.021 | 8 (44.4) | 8 (80.0) | 0.069 |
| Presence of periampullary duodenal diverticulum | 8 (8.0) | 2 (5.0) | 0.534 | 0 (0) | 0 (0) | 1.000 |
| Pancreatic involvement | 64 (64.0) | 8 (20.0) | < 0.001 | 6 (33.3) | 1 (10.0) | 0.172 |
| Quantitative radiological features* | ||||||
| Size of the ampullary mass (mm) | 21.68 ± 9.49 | 19.82 ± 10.61 | 0.317 | 20.10 ± 8.51 | 17.43 ± 3.82 | 0.374 |
| Angle of the distal CBD end (°) | 85.33 ± 49.94 | 103.43 ± 61.01 | 0.105 | 87.14 ± 56.25 | 130.84 ± 60.32 | 0.076 |
| Diameter of the CBD (mm) | 16.86 ± 12.37 | 17.38 ± 22.78 | 0.863 | 17.40 ± 4.55 | 15.86 ± 3.23 | 0.370 |
| Diameter of the MPD (mm) | 3.73 ± 2.81 | 3.93 ± 3.28 | 0.716 | 4.18 ± 4.14 | 5.21 ± 2.20 | 0.486 |
Qualitative data are expressed as n (%). Chi-square or Fisher’s exact test was used for comparisons among groups. Quantitative data are expressed as mean ± SD. Students’ t-test was used for comparisons among groups. Statistical significance (P < 0.05)
CBD, common bile duct; CT, computed tomography; IHD, intrahepatic ducts; MPD, main pancreatic duct