Table 2 Comparison of Clinical and CT imaging Characteristics between Type 1 AIP Patients with and without PaT
From: Pancreatic tumor in type 1 autoimmune pancreatitis: a diagnostic challenge
|  | AIP (n = 69) | AIP + PaC (n = 5) | P Value |
|---|---|---|---|
Male | 58 (84%) | 2 (40%) | 0.044 |
Age (year) | 61 (24–80) | 58 (42–76) | 0.845 |
Surveillance period (month) | 5 (1–109) | 3 (0–6) | 0.086 |
IgG4 (n = 65) |  |  | 0.561 |
 <1 time upper limit | 8 (14%) | 1 (20%) |  |
 1–2 times upper limit | 11 (17%) | 0 (0%) |  |
  ≥ 2 times upper limit | 41 (69%) | 4 (80%) |  |
CA-199 (n = 65, U/ml) | 19.5 (2.0–1987.0) | 21.4 (2.0–106.0) | 0.767 |
Biopsy at the initial visit | 41 (58%) | 5 (100%) | 0.150 |
Presence of extrapancreatic involvement | |||
 Bile duct | 63 (91%) | 3 (60%) | 0.087 |
 Kidney | 25 (36%) | 0 (0%) | 0.160 |
 Retroperitoneum | 9 (9%) | 2 (40%) | 0.157 |
CT imaging characteristics of pancreatic parenchyma | |||
 Enlargement pattern |  |  | 0.003 |
  Diffuse | 49 (71%) | 0 (0%) |  |
  Focal | 20 (29%) | 5 (100%) |  |
 Presence of atrophy | 10 (15%) | 1 (20%) | 0.564 |
 Presence of heterogeneity | 28 (41%) | 5 (100%) | 0.015 |
 Presence of low-density (n = 26) | 21 (30%) | 5 (100%) | 0.004 |
  Mass-like low-density | 6 (29%) | 4 (80%) | 0.055 |
  Relative density of low-density | |||
   Arterial phase |  |  | 1.000 |
    Hypoattenuating | 21 (100%) | 5 (100%) |  |
    Isoattenuating | 0 (0%) | 0 (0%) |  |
    Hyperattenuating | 0 (0%) | 0 (0%) |  |
   Venous phase |  |  | 0.562 |
    Hypoattenuating | 14 (67%) | 4 (80%) |  |
    Isoattenuating | 7 (33%) | 1 (20%) |  |
    Hyperattenuating | 0 (0%) | 0 (0%) |  |
  Absolute density of low-density (Hu) | |||
   Pre-enhanced phase | 42 (33–53) | 45 (28–45) | 0.769 |
   Arterial phase | 71 (51–96) | 53 (32–89) | 0.313 |
   Venous phase | 83 (57–112) | 81 (37–94) | 0.255 |
CT imaging characteristics of main pancreatic duct | |||
 Presence of dilatation | 16 (23%) | 1 (20%) | 1.000 |
 Presence of cutoff | 31 (45%) | 2 (40%) | 1.000 |
CT imaging characteristics of peripancreatic structures | |||
 Presence of halo sign | 43 (62%) | 2 (40%) | 0.374 |
 Presence of stranding | 14 (20%) | 3 (60%) | 0.076 |
 Presence of ascites | 2 (3%) | 1 (20%) | 0.192 |
 Presence of vessel stricture | 44 (64%) | 4 (80%) | 0.651 |