Imaging Anatomy of the Pancreas
Ben BarnardDepartment of Diagnostic Radiology; KHC
Outline Embryology Variants Gross anatomy Anatomical relations Arterial supply Venous drainage Lymphatic drainage Radiological anatomy
Embryology The pancreas is formed by dorsal and ventral buds originating
from the endodermal lining of the duodenum The smaller ventral bud arises in conjunction with the bile duct
and consists of two portions Left bud which atrophies during development Right bud which swings posteriorly and unites with the inferior division
of the dorsal bud
Langman’s Medical Embryology
Variants Agenesis of the dorsal pancreatic moeity
Pancreas with a head but no body or tail – very rare Left-sided pancreas
Effect of age with laxity of suspensory fascia Accessory nodules (pancreatic rests)
Can occur in the wall of the stomach, duodenum, jejunum , appendix, Meckel’s diverticulum (1-15% )
Pancreas divisum Failure of fusion of dorsal and ventral moeities Anterosuperior head and body drain via accessory ampulla Posterioinferior head drains to ampulla
Annular pancreas
Annular pancreas Occurs when the left portion of the ventral bud fails to atrophy
and migrates around the duodenum in the opposite direction to the normal right portion
Duodenum is thus surrounded bypancreatic tissue, and an annular pancreas is formed
This tissue constricts the duodenum and may cause complete obstruction
Gross Anatomy Retroperitoneal
organ 15cm long Transverse
mesocolon originates from anterior surface.
Head C-curve of duodenum (L2)
Uncinate process Inferior-medial extension
of head under SMA (L2) Neck
Overlies L1 vertebral body immediately to the left of the head
Body Extends left and slightly
superior (L1) Tail
Tapering portion extending to hilum of spleen (T12)
Various normal shapes
Anatomical Relations
Anterior relations Peritonium 1st part
duodenum Lesser sac and
stomach Transverse
colon/mesocolon
Anatomical Relations Posterior relations
CBD IVC PV Aorta SMA SMV Right renal vein Left kidney Crurae of
diaphragm.
Retroperitoneal Compartments
The pancreas (P) lies in the anterior pararenal space (APRS) together with the ascending and descending colon (C) and duodenum ST = stomach S = spleen RK = right kidney LK = left kidney A = aorta V = inferior vena cava LS = lesser sac PRS = perirenal space PPRS = posterior pararenal
space
Grants Anatomy
Pancreatic duct Pancreatic duct measures
3mm in the head 2mm in the neck 1mm in the tail
Unites with the common bile duct to form the ampulla of Vater and opens into the 2nd part of duodenum
Pancreatic duct variants
Santorini Wirsung
Arterial supply Pancreas neck, body and tail
Dorsal pancreatic artery (from splenic artery or coeliac trunk) Pancreatica magna artery ( emerges halfway along the splenic artery) Transverse pancreatic artery (travels along the length of the pancreatic duct
and anastomoses with the above arteries) Pancreas head
Superior pancreaticoduodenal artery (anterior and posterior branches from the gastroduodenal artery) Inferior pancreaticoduodenal artery (anterior and posterior branches from the superior mesenteric artery)
Venous drainage SMV Splenic vein Portal vein
Lymphatic drainage Along arterial blood supply to pre-aortic coeliac lymph
nodes
Radiological anatomy
US 3 - 7.5 MHz probe Sagittal, transverse and oblique planes Occasionally, may have non-visualization due to bowel
gas which can be overcome by:1. Fill stomach with fluid2. Position patient erect (liver descends)3. Prone position for tail
CT Similar density as
liver Density is reduced
with increasing age due to normal accumulation of fat
Homogenous enhancement post contrast
MRI
ERCP
MRCP
References• Imaging Anatomy of the Pancreas Referaat, Dr Frans Naude• Normal Findings in CT and MRI,Moeller• Pocket Atlas of Sectional Anatomy Computer Tomography and
Magnetic Resonance Imaging, Torsten B. Moeller, MD• Last’s anatomy 11th ed , Sinnatamby• Applied radiological anatomy , Butler• Atlas of human anatomy, F Netter• Pocket Atlas of Radiographic Anatomy,second edition,Moeller• Atlas of normal rontgen variants that may simulate disease, R
Keats• Color Atlas of Ultrasound Anatomy ,Berthold Block• Grant atlas of anatomy
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