Pancreatic ultrasound can be used to assess for pancreatic malignancy, pancreatitis and its complications, as well as for other pancreatic pathology.
On this page:
Preparation
Fast the patient to reduce interference from overlying bowel gas, which may otherwise make visualisation difficult.
Scanning technique
3-6 MHz curvilinear ultrasound transducer
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pancreatic body
anterior subxiphoid approach with the left lobe of the liver as an acoustic window
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adjuncts to improve visualisation
deep inspiration
push abdomen out to make a "beer belly" 1
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pancreatic head
in addition to the above, a right subcostal approach with the transducer angled medially may be useful 1
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pancreatic tail
can be difficult to visualise
a water filled stomach may be used as a window 1
scan coronally in a right lateral decubitus position using the spleen as an acoustic window
Macroscopic appearances
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variable echogenicity
in young patients, the pancreas is generally less fatty and therefore usually hypoechoic
with age, fatty replacement of pancreas can result in echogenicity similar to surrounding mesenteric fat
fatty sparing of the uncinate process
Measurements
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AP diameter
head: 34 mm
body: 29 mm
tail: 32 mm
length: 12-20 cm
pancreatic duct: ≤3 mm
Pathologies
acute pancreatitis: On the ultrasound, the affected pancreas usually appears swollen and hypoechoic, with surrounding tissue oedema
chronic pancreatitis: In a pancreatic ultrasound, findings may include an irregularly shaped gland, calcifications, and dilated pancreatic duct
pancreatic pseudocyst: A well-defined, hypoechoic or anechoic fluid-filled sac adjacent to the pancreas
pancreatic cysts: Can appear either anechoic or with internal debris on ultrasound imaging
pancreatic adenocarcinoma: On ultrasound examination, it often presents as an irregular hypoechoic mass with poorly-defined margins and possible invasion of nearby structures
pancreatic neuroendocrine tumours (PNETs): They may present on ultrasound as solid lesions with varying degrees of echogenicity
pancreatic abscess and infection: On ultrasound, these may be seen as complex hypoechoic or hyperechoic fluid collections within the pancreas
pancreatic trauma: Ultrasound may reveal focal areas of hypoechoic tissue, haematomas, or fluid collections as a result of damage to the gland
Practical Points
pancreatic ultrasound is useful in distinguishing between inflammatory and neoplastic lesions but can have limitations in characterising some complex cystic lesions
the use of contrast-enhanced ultrasound can improve the detection of focal pancreatic lesions
adjunct imaging modalities like computed tomography (CT) scan or magnetic resonance imaging (MRI) may be necessary for further evaluation in certain cases