Table 1.

Summary of Clinical and CT Imaging Characteristics of Type 1 AIP Patients with PaT

		PDAC (n = 3)		SEP (n = 1)	CCa (n = 1)
	Case 1a	Case 2	Case 3
Gender	Male	Male	Female	Female	Female
Surveillance period (month)	3	0	0	3	6
IgG4 (≤2 g/L, g/L)	6.9	5.2	4.6	0.3	4.1
CA-199 (0-35 U/ml, U/ml)	64.7	14.6	106.0	2.0	21.4
Biopsy at initial visit
Location	Pancreas	Pancreas	Pancreas	Pancreas	Pancreas
Evidence of PaT	No	Yes	Yes	No	No
Presence of extrapancreatic involvement
Bile duct	No	No	Yes	Yes	Yes
Kidney	No	No	No	No	No
Retroperitoneum	No	Yes	No	Yes	No
CT imaging characteristics of pancreatic parenchyma
Focal enlargement	Yes	Yes	Yes	Yes	Yes
Presence of atrophy	No	No	Yes	No	No
Presence of heterogeneity	Yes	Yes	Yes	Yes	Yes
Presence of low-density	Yes	Yes	Yes	Yes	Yes
Mass-like	Yes	Yes	Yes	No	Yes
Relative density
Arterial phase	Hypo	Hypo	Hypo	Hypo	Hypo
Venous phase	Hypo	Hypo	Hypo	Hypo	Iso
Absolute density (Hu)
Pre-enhanced phase	38	45	28	45	45
Arterial phase	53	51	32	76	89
Venous phase	68	81	37	94	94
CT imaging characteristics of main pancreatic duct
Dilatation	Yes	No	No	No	No
Cutoff	Yes	No	Yes	No	No
CT imaging characteristics of peripancreatic structures
Presence of halo sign	Yes	No	No	Yes	No
Presence of stranding	Yes	No	Yes	Yes	No
Presence of ascites	No	No	No	Yes	No
Presence of vessel stricture	Yes	Yes	Yes	Yes	No

Abbreviations: AIP autoimmune pancreatitis, PaT pancreatic tumor, PDAC pancreatic ductal adenocarcinoma, SEP solitary extramedullary plasmacytoma, CC cholangiocarcinoma, Hypo hypoattenuating, Iso Isoattenuating, Hu Hounsfield

^a Marked cases underwent pancreatic resection, and the presence of concurrent PaT in other unmarked cases were proved by biopsy at the initial visit or in the surveillance period