Pancreatic duct diameter

The diameter of the (main) pancreatic duct is a commonly assessed parameter in imaging.

Gross anatomy

The duct diameter is greatest at the head and neck region and is slightly narrower towards the body and tail. Its normal reported value ranges between 1-3.5 mm:

  • head: 3.5 mm
  • body: 2.5 mm
  • tail: 1.5 mm

The diameter of duct can increase with inspiration .

Related pathology

Abnormal dilatation of the pancreatic duct indicates obstruction of the normal flow of pancreatic secretions due to a distal (i.e. downstream) tumor or stricture. This can occur with acute pancreatitis, chronic pancreatitis or pancreatic neoplasms. Rarely, pancreatic duct dilatation can occur with tumoral hypersecretion of mucin (e.g. from intraductal papillary mucinous neoplasms).

Some authors suggest a main pancreatic duct dilatation (≥2.5 mm) without an obvious cause as an independent predictor of developing pancreatic cancer.