Diagnostic Ultrasound - Abdomen and Pelvis

Echogenic Bile
Diagnoses: Biliary System
TERMINOLOGY
• Biliary sludge, tumefactive sludge, biliary sand, microlithiasis
• Presence of particulate material (calcium
bilirubinate/phosphate or carbonate crystals with
cholesterol monohydrate crystals) in bile
• Larger particles (1-3 mm) are microliths, which may become
nidus for gallstones
IMAGING
• Amorphous, mid-/high-level echoes within gallbladder (GB)
• Sediment in dependent position
• Floating punctate echoes; may show ring-down artifact
• Lack of posterior acoustic shadowing
• Round, low to intermediate echogenicity mass-like "lesion"
• Note: Twinkling artifact may be mistaken for color flow
• Change patient position to demonstrate mobility of
intraluminal material to dependent portion
KEY FACTS
TOP DIFFERENTIAL DIAGNOSES
• Cholelithiasis
• Focal adenomyomatosis
• Gallbladder polyp
• Gallbladder empyema
• Blood clot
CLINICAL ISSUES
• Mostly asymptomatic
• May have clinical symptoms when complications occur
• Stone formation
• Biliary colic
• Acute acalculous/calculous cholecystitis
• Pancreatitis
DIAGNOSTIC CHECKLIST
• Consider biliary sludge when mobile mid-/high-level echoes
without acoustic shadowing are seen in GB
(Left) Longitudinal ultrasound
in a decubitus position shows
intraluminal sludge ſt with a
normal wall. The right kidney
is noted. (Right) Transverse
ultrasound shows a dependent
sludge layer in the gallbladder
ſt. The gallbladder wall is
asymmetrically mildly
thickened st.
(Left) Transverse color
Doppler ultrasound shows
dependent echogenic sludge
ſt with no color flow. The
gallbladder wall is mildly
thickened in this patient with
liver disease. (Right)
Longitudinal ultrasound in a
decubitus position shows
multiple bright intraluminal
echoes, which were mobile on
real-time imaging. Note the
"comet tail" artifacts ſt. The
gallbladder wall is normal.
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