Congenital anomalies of the pancreas

Pancreas divisum (Pancreas divisum)

The ductal system anomaly known as pancreas divisum (pancreas divisum) is characterized by a specific architectonics of the excretory pathways. In this pathology, the dorsal duct (also referred to as the accessory pancreatic duct, or ductus pancreaticus accessorius) drains through the minor duodenal papilla (papilla duodeni minor). Anatomically, the minor duodenal papilla is located cranially, meaning it is positioned higher relative to the major duodenal papilla (papilla duodeni major).

From an imaging perspective, multislice computed tomography (MSCT) enables the identification of a typical spatial configuration. A key feature is the course of the dorsal duct anteriorly relative to the common bile duct (ductus choledochus).

One of the important diagnostic markers identified on magnetic resonance cholangiopancreatography (MRCP) is santorinicele. This is a focal cystic outpouching of the terminal segment of the duct directly in the area of the minor papilla, which serves as a direct indicator of obstruction at this level.

The presence of pancreas divisum frequently leads to the development of chronic pancreatitis. On tomograms (both MSCT and MRCP) in such cases, the following are determined:

• Pronounced dilatation of the main duct (located typically anterior to the common bile duct) and its side branches.
• Presence of parenchymal calcifications (on MSCT).
• Visualization of small calculi (stones) directly within the lumen of the dilated duct.

Annular pancreas (Pancreas annulare)

Annular pancreas is a congenital pathology in which the pancreatic tissue forms a ring around the descending part of the duodenum. Diagnostic imaging relies on a comprehensive approach using various techniques:

1. CT enteroclysis: axial slices clearly visualize the parenchyma embracing the duodenum. An important technical requirement is adequate distension of the duodenal lumen with fluid; the images may also show a nasojejunal tube placed for the procedure.
2. MRCP: evaluates the ductal architecture in isolation. The method allows for the detection of an accessory pancreatic duct that mirrors the shape of the parenchyma and encircles the duodenum in a ring-like fashion.
3. Contrast-enhanced MRI with gadolinium: provides high tissue contrast. Tomograms reliably differentiate the duodenal lumen and the adjacent circular rim of the surrounding pancreatic parenchyma.

Aplasia of the dorsal pancreas

Aplasia of the dorsal pancreas is associated with impaired normal formation of the dorsal bud of the organ. The imaging appearance of this anomaly is highly specific and requires careful evaluation of medical history:

• On axial slices of routine computed tomography (CT), only the head of the pancreas can be identified.
• Coronal multiplanar reconstruction (MPR) is used to confirm the diagnosis. Image generation in the coronal plane allows for the evaluation of the organ along its entire anatomical length and reliably confirms the complete absence of the body and tail of the pancreas.

Critically important diagnostic criterion: the imaging appearance in aplasia is visually identical to the post-surgical resection state. Therefore, the diagnosis of congenital aplasia is valid exclusively in patients who have not previously undergone surgical interventions on the organ.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Technique for performing CT enteroclysis with nasojejunal tube placement
• Features of using contrast-enhanced MRI with gadolinium for parenchymal evaluation
• MRCP: principles of visualization of the pancreatobiliary tree
• Differential diagnosis of causes of pancreatic duct dilatation

Other topics in the section "Diagnostic Radiology of the Abdominal Organs"

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