Diagnostic Ultrasound - Abdomen and Pelvis

Echogenic Material in Gallbladder
Differential Diagnoses: Biliary System
DIFFERENTIAL DIAGNOSIS
Common
• Cholelithiasis
• Sludge/Sludge Ball/Echogenic Bile
Less Common
• Blood Clot
• Complicated Cholecystitis
• Gas Within Gallbladder Lumen
• Drainage Catheter
• Tumor: Primary or Secondary
• Parasitic Infestation
ESSENTIAL INFORMATION
Helpful Clues for Common Diagnoses
• Cholelithiasis
○ Highly reflective intraluminal structure within gallbladder
lumen
○ Posterior acoustic shadowing
○ Gravity-dependent and mobile
○ Variants
– Bright echoes with acoustic shadowing in gallbladder
fossa representing gallbladder packed with stones
– Nonshadowing gallstones, usually small (< 5 mm)
– Double-arc shadow sign or wall-echo-shadow (WES)
sign
– Immobile adherent/impacted gallstones
○ Complication: Acute calculous cholecystitis: Gallbladder
distension and wall thickening, sonographic Murphy sign,
pericholecystic fluid
• Sludge/Sludge Ball/Echogenic Bile
○ Amorphous, mid-/high-level echoes within gallbladder,
lack of shadowing
○ Sediment in dependent portion
○ Mobile on changing patient's position without posterior
acoustic shadowing
○ Sludge ball: Aggregate with well-defined, round contour,
moves slowly
○ Can be isoechoic to liver resulting in "hepatization" of
gallbladder
Helpful Clues for Less Common Diagnoses
• Blood Clot
○ Echogenic/mixed echoes or blood fluid level within
gallbladder
○ Occasionally retractile, conforming to gallbladder shape
○ Post trauma, post surgery, or after hepatobiliary
intervention; associated with gastrointestinal bleed
• Complicated Cholecystitis
○ Gangrenous cholecystitis: Intraluminal echogenic debris
and membranes
– Asymmetric wall thickening, marked wall irregularities
○ Emphysematous cholecystitis: Gas in gallbladder wall and
lumen
○ Gallbladder empyema
– Distended pus filled gallbladder, echogenic contents,
no shadowing
• Gas in Lumen
○ Iatrogenic from interventional procedure or endoscopy
○ Secondary to fistula with bowel as in gallstone ileus
– Small bowel obstruction and pneumobilia, CT more
definitive
• Catheter
○ History of percutaneous or endoscopic drainage
○ Tubular, parallel echogenic lines, ± "pig tail" loop, manmade
configuration
• Tumor
○ Primary cancers involve wall ± endoluminal mass, stones,
and extension to liver
○ Hematogenous metastases most commonly from
melanoma
– Multiple > single broad-based, hypoechoic, polypoid
lesions, ± wall thickening
○ Look for color Doppler flow in mass, confirm with
spectral Doppler
Helpful Clues for Rare Diagnoses
• Parasitic Infestation
○ Tubular, parallel echogenic lines
(Left) Longitudinal decubitus
ultrasound of the gallbladder
shows a fundal curvilinear
echo ſt with a strong acoustic
shadow st. Note the normal
wall with no cholecystitis.
(Right) Transverse decubitus
ultrasound of the gallbladder
shows a thick wall ,
shadowing stones ſt, and
sludge st in a patient with
acute cholecystitis.
Cholelithiasis
Cholelithiasis
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