Pancreatic and duodenal injury

CT · MRI

First and second year — the floor first, then every step

The injury that looks trivial on the first CT: find the laceration across the pancreatic neck and ask whether it crosses the main duct; separate a duodenal wall haematoma from a perforation.

Orient first

  • The pancreas is crushed against the spine, so the neck and body over the vertebra are the usual sites — in children, handlebar injuries; in adults, the steering wheel or a seatbelt.
  • Early CT can be near-normal: fluid between the splenic vein and the pancreas, or peripancreatic fluid alone, may be the only sign on the day of injury.
  • The MAIN PANCREATIC DUCT decides management: a ductal transection needs intervention; a parenchymal injury with an intact duct usually does not.

Acquire the study

  • Pancreatic/portal venous phase with thin slices and CURVED reformats along the pancreatic duct; read on a narrow soft-tissue window.
  • Positive oral contrast is not routine; if given, it helps show duodenal leak.

The manoeuvre

  • Follow the gland from head to tail on thin slices and a curved reformat; a laceration is a low-attenuation line across the parenchyma.
  • Judge DEPTH: a laceration through more than about half the thickness of the gland is likely to involve the duct.
  • Fluid between the splenic vein and the pancreas, peripancreatic fluid, and fluid in the anterior pararenal space.
  • Duodenum: wall thickening or intramural haematoma (crescentic, narrowing the lumen) versus perforation — extraluminal gas in the retroperitoneum around the duodenum and extraluminal oral contrast.
  • Retroperitoneal gas on the lung window next to the second and third parts of the duodenum.

What confirms it

  • Pancreatic laceration: a low-attenuation line across the gland with peripancreatic fluid; duct injury proved on MRCP or ERCP, or inferred from a full-thickness laceration.
  • Duodenal perforation: extraluminal gas or oral contrast; haematoma alone narrows the lumen without leak.

What licenses you to exclude it

  • An early normal CT does not exclude pancreatic injury; with persisting pain or a rising amylase/lipase, repeat CT or MRCP.

The classic misread

  • Calling an unopacified duodenum or jejunum a peripancreatic collection.
  • Missing retroperitoneal gas because the study was not re-windowed.

Reporting the injury

Classification to use

  • AAST pancreas: I — minor contusion or superficial laceration without duct injury; II — major contusion or laceration without duct injury or tissue loss; III — distal transection or parenchymal injury with duct injury; IV — proximal transection or parenchymal injury involving the ampulla (proximal = to the right of the superior mesenteric vein); V — massive disruption of the pancreatic head.
  • AAST duodenum (haematoma versus laceration by extent of circumference and part) — name it if used.

Measurements — and how to take them

  • Laceration depth as a fraction of the gland thickness at that level.
  • Duodenal haematoma length and residual lumen.

What to report

  • Site of the laceration relative to the superior mesenteric vein (head/neck versus body/tail), depth, and duct status (intact / indeterminate / disrupted — and on what evidence).
  • Duodenal wall haematoma (length, luminal narrowing) or perforation (gas, contrast leak).
  • Collections and their relation to the duct.

How to report it

  • CT: "Laceration of the pancreatic neck extending through more than half of the gland thickness, to the left of the superior mesenteric vein, with fluid between the pancreas and the splenic vein. Main duct disruption is likely; MRCP recommended. AAST grade III pancreatic injury if confirmed."
  • MRI: "Abrupt cut-off of the main pancreatic duct at the neck laceration with a communicating peripancreatic collection."

What not to report

  • Do not call the duct intact on CT alone when the laceration is deep; say it is indeterminate.

Associated injuries to look for

  • Chance fracture of L1–L2, duodenal injury, hepatic and splenic injury, jejunal injury.

What changes management

  • Main duct transection — distal pancreatectomy, stenting or drainage depending on site; proximal to the SMV is more complex.
  • Duodenal perforation — surgery; intramural haematoma alone — usually conservative.

Reference values

Each value carries the caveat that keeps it from being misused. Normal limits and diagnostic criteria are kept apart on purpose: a disease cut-off read as a normal range is the more dangerous mistake.

Normal limits

  • Main pancreatic duct · diameter in the head/bodyup to 3 mm

    Tapers toward the tail; mild age-related dilatation is recognised.

    USG · CT · MRI

  • Pararenal spaces · Anterior versus posterior pararenal — how to report them

    named retroperitoneal compartments; pancreatitis lives in the anterior pararenal space, a psoas haematoma in the posterior — not a fake “space millimetre”

    Name the compartment. Fluid in one space is not “ascites”.

    CT

See it on real cases

Direct links to Radiopaedia — the reference article and worked cases with their images. Each opens on Radiopaedia.

Key papers

Reviews and guidelines from RSNA, ESR and related journals. Each opens at its DOI.

  1. Pancreatic Trauma: Imaging Review and Management Update ↗Ayoob AR, Lee JT, Herr K, et al. · RadioGraphics 2021RSNA · PubMed
  2. Diagnosis and classification of pancreatic and duodenal injuries in emergency radiology ↗Linsenmaier U, Wirth S, Reiser M, et al. · RadioGraphics 2008RSNA · PubMed
  3. Imaging of blunt pancreatic trauma ↗Rekhi S, Anderson SW, Rhea JT, et al. · Emergency Radiology 2010ASER · PubMed
  4. Early computed tomography may miss main pancreatic duct injury in distal pancreatic trauma: a prospective surgically verified diagnostic accuracy study ↗Tri PM, Hung NT, Liet DH, et al. · Emergency Radiology 2026ASER · PubMed

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