Topics

Topic

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Neck of pancreas

The neck of the pancreas is the short segment of the gland that connects the pancreatic head to the body. It is the narrowest portion of the pancreas, typically 1.5–2 cm in length, and lies anterior to the superior mesenteric vessels. Despite its small size, the pancreatic neck has critical surgical and radiologic significance because it serves as a key landmark for the portosplenic confluence and is a common site for pancreatic tumors.

Synonyms

  • Pancreatic neck

  • Isthmus of pancreas

  • Narrow segment of pancreas

Location and Relations

  • Anteriorly: Posterior surface of the stomach (lesser curvature region) and peritoneum of the lesser sac

  • Posteriorly: Superior mesenteric vein (SMV), portal vein formation (junction of SMV and splenic vein), and superior mesenteric artery (SMA)

  • Superiorly: Pancreatic body and origin of splenic vein

  • Inferiorly: Pancreatic head, duodenum, and SMA/SMV root

  • Laterally:

    • Right: Pancreatic head

    • Left: Pancreatic body

Function

  • Acts as a conduit connecting pancreatic head and body

  • Transmits part of the main pancreatic duct (duct of Wirsung) across its substance

  • Forms a surgical landmark for division in pancreaticoduodenectomy (Whipple procedure)

  • Contributes to both exocrine (enzymatic secretion) and endocrine (insulin, glucagon) functions as part of the pancreas

Clinical Significance

  • Pancreatic carcinoma: Commonly arises in pancreatic head/neck, causing obstruction of bile duct and portal vein involvement

  • Surgical landmark: Division site during Whipple procedure

  • Vascular relevance: Its relation to the SMV and portal vein is critical for tumor resectability

  • Pancreatitis: Inflammation may involve the neck, leading to localized edema or fluid collections

  • Imaging relevance: Key site evaluated in CT/MRI staging of pancreatic cancer

MRI Appearance

T1-weighted images:

  • Normal parenchyma: intermediate signal intensity (slightly higher than liver)

  • Fat planes: appear bright, delineating the gland

  • Pathology: focal tumors appear as low-signal intensity masses

T2-weighted images:

  • Normal pancreas: relatively low-to-intermediate signal compared to fluid

  • Pancreatic duct: bright linear tubular structure traversing neck

  • Pathology: cysts or fluid collections appear bright; tumors often show mildly increased signal compared to normal parenchyma

STIR (Short Tau Inversion Recovery):

  • Normal parenchyma: low-to-intermediate signal

  • Inflammatory changes: bright signal intensity

  • Fat suppressed → helps highlight abnormal parenchymal edema

T1 GRE Fat-Sat Pre-Contrast:

  • Normal pancreas: homogeneous intermediate signal

  • Focal lesions: usually hypointense compared to normal parenchyma

T1 GRE Fat-Sat Post-Gadolinium:

  • Normal pancreas: intense, homogeneous early enhancement due to rich vascularity

  • Tumors: appear as hypoenhancing focal areas relative to surrounding parenchyma

  • Pancreatitis: patchy heterogeneous enhancement; necrotic areas remain non-enhancing

  • Cysts: do not enhance; walls may enhance if inflamed

CT Appearance

Non-Contrast CT:

  • Normal pancreas: soft tissue density, slightly higher attenuation than muscle

  • Fat planes: visible anterior and posterior to neck

  • Tumors: appear as ill-defined, hypoattenuating areas

Post-Contrast CT:

  • Normal pancreas: enhances intensely and homogeneously in the arterial phase

  • Tumors: hypoattenuating relative to surrounding gland in arterial and venous phases

  • Pancreatitis: shows diffuse or focal gland enlargement, heterogeneous enhancement, and peripancreatic fat stranding

  • Cysts/abscesses: low-attenuation areas, with rim enhancement if infected

MRI image

Neck of pancreas MRI axial anatomy image-img-00000-00000

MRI image

Neck of pancreas MRI coronal anatomy image-img-00000-00000

CT image

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CT image

Neck of pancreas CT coronal anatomy image-img-00000-00000