Table 1.

Imaging findings favoring an inflammatory or malignant cause[39]

Inflammatory cause	Malignant cause
Penetrating duct sign	Abrupt cutoff of the pancreatic duct
Collateral or side branch dilation	Upstream obliteration of side branches
Duct-to-parenchyma ratio < 0.34	Duct-to-parenchyma ratio ≥ 0.34
AIP: occasionally perivascular involvement	Vessel encasement and caliber changes
SMA-to-SMV ratio < 1.0	SMA-to-SMV ratio ≥ 1.0

AIP: Autoimmune pancreatitis; SMA: Superior mesenteric artery; SMV: Superior mesenteric vein.