Table 1.
The CT-based image features used in this study, with possible values, summary statistics and inter-reader agreement
| Feature | Possible values and summary statistics | Inter-reader agreement (%); Cohen’s kappa |
|---|---|---|
| Disease in mesentery |
Yes: 50% (10/20) No: 50% (10/20) |
95%; 0.90 |
| Peritoneal disease in paracolic gutters |
Yes: 80% (16/20) No: 20% (4/20) |
100%; 1.0 |
| Peritoneal disease in Pouch of Douglas |
Yes: 75% (15/20) No: 25% (5/20) |
85%; 0.57 |
| Peritoneal disease in spleen/left upper quadrant |
Yes: 85% (17/20) No: 15% (3/20) |
100%; 1.0 |
| Peritoneal disease in lesser sac |
Yes: 30% (6/20) No: 70% (14/20) |
90%; 0.76 |
| Peritoneal disease in liver/right upper quadrant |
Yes: 70% (14/20) No: 30% (6/20) |
100%; 1.0 |
| Number of locations with peritoneal disease |
0: 10% (2/20) 1: 5% (1/20) 2: 5% (1/20) 3: 5% (1/20) 4: 30% (6/20) 5: 20% (4/20) 6: 25% (5/20) |
90%; 0.62 |
| Peritoneal disease calcifications |
Yes: 5% (1/20) No: 95% (19/20) |
95%; N/A |
| Peritoneal disease omental implant |
Yes: 95% (19/20) No: 5% (1/20) |
90%; 0.5 |
| Shape of peritoneal disease |
Diffuse: 15% (3/20) Predominantly diffuse: 50% (10/20) Predominantly nodular: 30% (6/20) Nodular: 0% (0/20) Peritoneal enhancement only: 0% (0/20) No peritoneal disease: 5% (1/20) |
90%; 0.71 |
| Infrarenal retroperitoneal lymphadenopathy |
Yes: 30% (6/20) No: 70% (14/20) |
100%; 1.0 |
| Pelvic lymphadenopathy |
Yes: 15% (3/20) No: 85% (17/20) |
95%; 0.77 |
| Inguinal lymphadenopathy |
Yes: 0% (0/20) No: 100% (20/20) |
100%; N/A |
| Porta/celiac/gastro lymphadenopathy |
Yes: 25% (5/20) No: 75% (15/20) |
100%; 1.0 |
| Retrocrural lymphadenopathy |
Yes: 5% (1/20) No: 95% (19/20) |
95%; N/A |
| Supradiaphragmatic lymphadenopathy |
Yes: 45% (9/20) No: 55% (11/20) |
100%; 1.0 |
| Thoracic lymphadenopathy |
Yes: 0% (0/20) No: 100% (20/20) |
100%; N/A |
| Number of locations with lymphadenopathy |
0: 45% (9/20) 1: 15% (3/20) 2: 20% (4/20) 3: 5% (1/20) 4: 15% (3/20) |
100%; 1.0 |
| Metastases in liver |
Yes: 0% (0/20) No: 100% (20/20) |
100%; N/A |
| Metastases in lung |
Yes: 5% (1/20) No: 95% (19/20) |
100%; 1.0 |
| Metastases in pleura |
Yes: 10% (2/20) No: 90% (18/20) |
100%; 1.0 |
| Metastases in spleen |
Yes: 0% (0/20) No: 100% (20/20) |
100%; N/A |
| Metastases in other locations |
Yes: 0% (0/20) No: 100% (20/20) |
100%; N/A |
| Number of locations with metastases |
0: 85% (17/20) 1: 15% (3/20) |
100%; 1.0 |
| Metastases calcifications |
Yes: 0% (0/20) No: 100% (20/20) |
100%; N/A |
| Size of pleural effusions |
No pleural effusions: 65% (13/20) Small: 20% (4/20) Moderate/Large: 15% (3/20) |
95%; 0.91 |
| Pleural metastases removed |
Pleural effusion: 5% (1/20) [NA]: 95% (19/20) |
100%; 1.0 |
| Pleural effusion metastases removed |
Small: 5% (1/20) [NA]: 95% (19/20) |
100%; 1.0 |
| Size of ascites |
No ascites: 15% (3/20) Trace or small: 40% (8/20) Moderate or large: 35% (9/20) |
95%; 0.92 |
| Mass laterality |
No mass: 10% (2/20) Left: 5% (1/20) Right: 5% (1/20) Bilateral: 85% (16/20) |
90%; 0.73 |
| Mass calcifications |
Yes: 10% (2/20) No: 90% (18/20) |
95%; 0.64 |
| Mass septations |
Yes: 10% (2/20) No: 90% (18/20) |
90%; N/A |
| Mass internal architecture |
Cystic: 0% (0/20) Predominantly cystic: 0% (0/20) Mixed: 35% (7/20) Predominantly solid: 55% (11/20) Solid: 10% (2/20) |
75%; 0.38 |
| Length of largest lesion |
Median: 63 mm Range: 24 mm to 116 mm |
N/A |
N/A, not applicable. Inter-reader agreement is shown as absolute agreement and Cohen’s kappa statistics for the two radiologists. In case of disagreement, a third radiologist acted as arbitrator. In case one or both readers scored all cases the same value, we were not able to calculate kappa values