Diagnostic Ultrasound - Abdomen and Pelvis

Hyperechoic Gallbladder Wall
Differential Diagnoses: Biliary System
DIFFERENTIAL DIAGNOSIS
Common
• Large Gallstone
• Porcelain Gallbladder
• Contracted Gallbladder With Gallstones
• Gas-Filled Duodenal Bulb
Less Common
• Hyperplastic Cholecystosis
• Adherent Gallstones
• Emphysematous Cholecystitis
• Fistula to Gallbladder
• Iatrogenic: Post Endoscopic Retrograde
Cholangiopancreatography (ERCP)
ESSENTIAL INFORMATION
Key Differential Diagnosis Issues
• Differentiate gas-filled duodenum from abnormal
gallbladder by location and repositioning patient
• Duodenum may be mistaken for gallbladder post
cholecystectomy
○ Relevant surgical history is key
○ Look for cholecystectomy scars if no history is available
○ Correlate with other imaging
• Gas in gallbladder may be a surgical emergency
○ If unclear, confirm with CT
Helpful Clues for Common Diagnoses
• Large Gallstone
○ Strong acoustic impedance at wall-stone interface with
posterior shadowing
○ Wall-echo-shadow appearance (optimize technique)
○ Mobile on changing patient's position unless stone is
very large and gallbladder is contracted around it
• Contracted Gallbladder With Gallstones
○ Multiple, closely packed echogenic stones without bile
mimic echogenic gallbladder wall
○ Thickened gallbladder wall
○ Gallstones may not move on changing patient's position
if gallbladder is severely contracted
• Gas-Filled Duodenal Bulb
○ Observe peristalsis
○ Move patient to move gas or have patient drink water to
confirm
• Porcelain Gallbladder
○ Diffuse gallbladder wall calcification
– Echogenic curvilinear line in gallbladder fossa
– Dense posterior acoustic shadowing
○ Segmental form: Interrupted echogenic line on anterior
wall
– Or multiple separate coarse echogenic foci/clumps in
wall with posterior acoustic shadowing
Helpful Clues for Less Common Diagnoses
• Hyperplastic Cholecystosis
○ Focal, diffuse or segmental gallbladder wall thickening
○ Tiny echogenic foci in gallbladder wall with characteristic
"comet tail" artifacts
○ Segmental form: Transition from normal to thick wall in
mid gallbladder producing "hourglass" gallbladder
• Adherent Gallstones
○ Not curvilinear in configuration or mobile
• Emphysematous Cholecystitis
○ Complicated form of acute cholecystitis
○ Clinical evidence of fulminant biliary sepsis is usually
present
○ Gas in gallbladder wall/lumen
– Echogenic crescent in gallbladder with reverberation
artifacts ("dirty" shadowing)
○ More common in diabetes and immunosuppressed
patients
• Gallbladder Fistula
○ Spontaneous fistula from erosion of gallstone into
duodenum: Gallstone ileus
○ Fistula to gallbladder from adjacent bowel malignancy
• Post ERCP or Biliary Stent
○ Known history of intervention
○ Gas in gallbladder without signs of cholecystitis
(Left) Transverse oblique
ultrasound shows a large,
curved, echogenic structure ſt
within the gallbladder casting
a dense posterior acoustic
shadow. The gallbladder wall
is seen separately. This is
the wall-echo-shadow sign,
which differentiates a large
gallstone from a porcelain
gallbladder. (Right) Oblique
transabdominal ultrasound
shows numerous small
shadowing echogenic
gallstones ſt filling a
contracted gallbladder .
The gallbladder wall is thick
suggesting chronic
cholecystitis.
Large Gallstone
Contracted Gallbladder With Gallstones
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