Diagnostic Ultrasound - Abdomen and Pelvis

Choledocholithiasis
Diagnoses: Biliary System
TERMINOLOGY
• Cholangiolithiasis, hepatolithiasis, biliary calculi, common
bile duct (CBD) stones
IMAGING
• Transabdominal ultrasound: Most stones appear as highly
echogenic foci with posterior acoustic shadowing
○ First-line imaging modality
○ Most often found in periampullary region/distal portion
of CBD, can be obscured by gas
• ERCP: Radiolucent, faceted, or angular filling defects within
bile ducts
○ "Gold" standard, is diagnostic and potentially therapeutic
• MRCP: Low-intensity filling defects within increased signal
intensity bile ducts
○ Very sensitive for detection of bile duct stones.
• NECT: Attenuation of stones varies from less than water
density, through soft tissue, to dense calcification
○ Not very sensitive for detection of bile duct stones
KEY FACTS
TOP DIFFERENTIAL DIAGNOSES
• Cholangiocarcinoma, ampullary mass
• Biliary parasitic infection, ascending cholangitis, recurrent
pyogenic cholangitis
PATHOLOGY
• Passage of gallstones into biliary ductal system (more
common) vs. de novo stone formation within ducts
• Can cause obstruction with subsequent ductal dilation
CLINICAL ISSUES
• Presentation: RUQ pain, pruritus, jaundice; however, may
be asymptomatic
• May present with acute complication: cholangitis,
pancreatitis
DIAGNOSTIC CHECKLIST
• Rule out other causes of CBD obstruction
(Left) Graphic shows multiple,
nonobstructive stones ſt in
the distal common bile duct
and gallbladder . (Right)
An echogenic focus ſt with
posterior shadowing that is
compatible with a stone is
present within the common
bile duct (CBD) on this
longitudinal US. The CBD is
located anterior to the hepatic
artery and the portal vein
. The hepatic artery crosses
in between the portal vein and
CBD.
(Left) More caudally, there are
several more stones ſt, which
are seen as echogenic
shadowing foci, within the
CBD extending to the level
of the head of the pancreas.
(Color Doppler ultrasound is
helpful to distinguish the
biliary ducts from the adjacent
vasculature.) (Right) A spot
fluoroscopic image from the
subsequent endoscopic
retrograde
cholangiopancreatography
(ERCP) procedure
demonstrates several filling
defects, compatible with
stones , within the CBD .
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