pancreas

pancreas

• Challenging organ for sonographers due to deep retroperitoneal location

• Lies posterior to the stomach, duodenum, and proximal jejunum

• CT & MRI – primary imaging modalities

• Ultrasound – more accessible and affordable

sonographers responsibilities

• Distinguish normal vs abnormal gland appearance

• Image ductal system

• Differentiate inflammation from malignancy

• Assist with FNA (Fine Needle Aspiration) when lesion found

Anatomy of a Pancreas

• Lies anterior to L1–L2, deep in epigastrium & left hypochondrium

• Extends horizontally from duodenum (right) → splenic hilum (left)

• Major posterior landmarks: aorta and IVC

• Variations: transverse, horseshoe, sigmoid, L-shaped, inverted V

Head of Pancreas

• Lies in C-loop of duodenum

• Anterior to IVC

• Posterior border: portal venous system

• Superior border: celiac axis

Neck of Pancreas

• Anterior to portal-splenic confluence

• Portal vein forms posterior to neck

Body of Pancreas

• Posterior border: splenic vein

• Anterior: stomach

• Joins with SMV and splenic vein to form portal vein

Tail of Pancreas

• Most difficult to image

• Extends to splenic hilum

• Posterior: splenic vein

• Superior: splenic artery

• Anterior: stomach

What are the measurements of the pancreas

• Head <3 cm

• Neck <2.5 cm

• Body <2.5 cm

• Tail <2.0 cm

Characteristics of a Pancreas

• Echogenicity: greater than liver; equal or greater than spleen

• Echotexture: homogeneous

• Surface: smooth to slightly lobular (islets of Langerhans)

Vascular Supply

• Splenic artery → body & tail

• Celiac axis branches: splenic, common hepatic, gastroduodenal arteries

• SMA, portal vein, and CBD nearby

congenital anomalies

Agenesis

Pancreas divisum

ectopic pancreas

annular pancreas

Agenesis

absence of body/tail

Pancreas divisum

ducts fail to fuse

Ectopic Pancreas

tissue in abnormal location

Annular pancreas

encircles duodenum

Exocrine

produces digestive enzymes ( pancreatic juice)

lipase

fats

Amylase

carbohydrates

trypsin, chymotrypsin, carboxypeptidase

proteins

nucleuses

nucleic acids

Endocrine

• Beta cells – Insulin (↓ glucose)

• Alpha cells – Glucagon (↑ glucose)

• Delta cells – Somatostatin (inhibits α & β cells)

Amylase

Increased in: Acute pancreatitis, mumps, ischemic bowel, PID

Notes: 2x normal

Lipase

increased in: Acute pancreatitis, carcinoma

Notes: more specific than amylase

urine amylase

increased in: pancreatitis

notes: prolonged elevation

glucose

increased in: diabetes, chronic liver disease, pancreatic tumor

notes: endocrine dysfunction

scanning techniques

• Positions: Supine, LLD, Semi-Fowler’s

• Probe: 5–7 MHz curved sector

• Technique: Transverse or transverse-oblique angles

• Use deep inspiration for better window

Panc Head landmarks

Anterior to IVC; lateral to duodenum; GDA anterolateral; CBD posteromedial

Uncinate landmark

Anterior to IVC, posterior to SMV

body landmark

Anterior to SMA, SMV, aorta, splenic vein

tail landmark

Medial to spleen; superior to left kidney

Pancreatitis

• Inflammation of pancreas due to duct blockage/enzyme leakage

• Causes: Gallstones (40–60%), alcohol abuse

• Symptoms: Severe mid-epigastric pain, nausea, vomiting

• Types:
  

  • Acute: mild to severe; hypoechoic enlarged gland

  • Chronic: recurrent attacks → fibrosis, calcifications, pseudocysts

Complications of pancreatitis

• Pseudocysts (10–20% of acute cases)

• Spontaneous rupture → peritonitis (50% mortality)

• Abscess formation

• Hemorrhagic or phlegmonous pancreatitis

cystic lesions

• Polycystic disease

• Congenital cysts

• Cystic fibrosis (fatty replacement, cyst formation)

• Von Hippel-Lindau syndrome

• Solitary cysts

Exocrine tumors

Adenocarinoma

serous cystadenoma

mucinous cystadenoma/carcinoma

adenocarcinoma

• most common (90%), often in head, >60 years
  

  • Causes CBD obstruction, jaundice, weight loss, Courvoisier sign

Serous Cystadenoma

benign, multiple small cysts

mucinous cystadenoma/ carcinoma

malignant, few large cysts

Endocrine( islet-cell tumors)

• May occur alone or with MEN 1 syndrome

• Types:
  

  • Insulinoma (β-cell): most common, benign, hypoglycemia symptoms

  • Gastrinoma (G-cell): excess gastrin → peptic ulcers

  • Nonfunctioning tumors: large, often malignant, in pancreatic head

Endocrine Metastatic disease

rare, from melanoma, breast, GI, or lung cancer