Diagnostic Ultrasound - Abdomen and Pelvis

Approach to Pancreatic Sonography
Cystic Pancreatic Lesions
Cystic lesions of the pancreas are common, and include
pseudocysts, simple cysts, and cystic neoplasms such as serous
and mucinous cystadenomas, intraductal papillary mucinous
neoplasm (IPMN), and solid pseudopapillary neoplasm.
Ultrasound can demonstrate the presence of thickened
septations, soft tissue nodules, calcifications, or associated
ductal dilatation, when present. In conjunction with the clinical
history and the patient age and gender, these ultrasound
findings are suggestive of the diagnosis. Ultimately,
endoscopic ultrasound or contrast-enhanced CT or MR is
required for definitive characterization.
Solid Pancreatic Lesions
Pancreatic ductal adenocarcinoma is the most common solid
pancreatic neoplasm. Ultrasound is frequently an initial
imaging study obtained to evaluate associated obstructive
jaundice or abdominal pain. The appearance is typically that of
a hypoechoic, poorly defined mass with limited acoustic
penetration. Secondary pancreatic and biliary ductal dilatation
is well visualized but not specific, as chronic pancreatitis can
have this finding as well. Although ultrasound is relatively
sensitive and specific for ductal adenocarcinoma, contrastenhanced
CT is required for complete characterization and
staging.
Transabdominal ultrasound is limited in evaluating for
neuroendocrine tumors, most of which are functional and
detected clinically when still small in size. Nonfunctioning
neuroendocrine tumors tend to be large and may be detected
when ultrasound is obtained to evaluate for associated upper
abdominal symptoms. In contrast to ductal adenocarcinomas,
they appear well circumscribed.
Differential Diagnosis
Pancreatic Duct Dilatation
• Chronic pancreatitis
• Pancreatic ductal carcinoma
• Obstructing distal common bile duct stone
• Intraductal papillary mucinous neoplasm (IPMN)
Diffuse Pancreatic Enlargement
• Acute pancreatitis
• Autoimmune pancreatitis
• Lymphoma
Cystic Pancreatic Mass
• Pancreatic pseudocyst
• Serous cystadenoma of pancreas
• Mucinous cystic neoplasm (MCN)
• Intraductal papillary mucinous neoplasm (IPMN)
• Necrotic pancreatic ductal carcinoma
• Cystic pancreatic neuroendocrine tumor
• Congenital cyst
• Lymphoepithelial cyst
• Cystic metastasis
Solid Pancreatic Mass
• Pancreatic ductal carcinoma
• Focal acute pancreatitis
• Chronic pancreatitis
• Pancreatic neuroendocrine tumor
• Metastasis
• Lymphoma
• Solid pseudopapillary neoplasm
• Intrapancreatic splenule
Selected References
1. D'Onofrio M. Ultrasonography of the Pancreas. Milan: Springer, 2012
2. O'Connor OJ et al: Imaging of acute pancreatitis. AJR Am J Roentgenol.
197(2):W221-5, 2011
3. D'Onofrio M et al: Ultrasonography of the pancreas. Contrast-enhanced
imaging. Abdom Imaging. 32(2):171-81, 2007
4. Martínez-Noguera A et al: Ultrasonography of the pancreas. Conventional
imaging. Abdom Imaging. 32(2):136-49, 2007
5. Oktar SO et al: Comparison of conventional sonography, real-time
compound sonography, tissue harmonic sonography, and tissue harmonic
compound sonography of abdominal and pelvic lesions. AJR Am J
Roentgenol. 181(5):1341-7, 2003
6. Abu-Yousef MM et al: Improved US visualization of the pancreatic tail with
simethicone, water, and patient rotation. Radiology. 217(3):780-5, 2000
Diagnoses: Pancreas
(Left) Transverse ultrasound
utilizing left lobe of the liver
as an acoustic window shows
the pancreatic neck and body
are hyperechoic relative to
the liver . Gas from the
stomach partially obscures the
tail st. The splenic vein is
posterior ſt. The normal
caliber duct is partially visible
. (Right) Color Doppler US
at the same level in a different
patient shows red flow in the
splenic vein towards the
transducer ſt, and blue flow
in the superior mesenteric vein
away from the transducer .
The common hepatic artery is
anterior st.
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