Cholelithiasis (gallstone disease) is the presence of one or more gallstones in the gallbladder. It has a prevalence of 10-15% in the general population and most are asymptomatic. In symptomatic cases, biliary colic (postprandial right upper quadrant pain) is the primary clinical finding. US is the primary diagnostic modality and hyperechoic structure + posterior acoustic shadow + gravitational mobility form the classic triad. Stones may be cholesterol stones (80%), pigment stones (15-20%), or mixed.
Age Range
20-80
Peak Age
50
Gender
Female predominant
Prevalence
Common
Gallstone formation is based on disruption of bile component balance. Cholesterol stones are the most common type (80%) and result from the triad of cholesterol supersaturation in bile, mucosal nucleation factors, and gallbladder hypomotility. When cholesterol supersaturation exceeds the capacity of bile acids and phospholipids to keep cholesterol in solution, cholesterol crystals precipitate. These crystals grow within mucus gel to form macroscopic stones. Pigment stones result from bilirubin metabolism disorders — increased unconjugated bilirubin in hemolysis or biliary infection triggers calcium bilirubinate precipitation. The hyperechoic appearance of stones on US results from strong reflection of ultrasound waves by calcium and cholesterol crystals, and acoustic shadow from blocked ultrasound transmission behind them.
Pathognomonic triad of gallstones on US: 1) Hyperechoic structure — strong reflection from high acoustic impedance of the stone, 2) Posterior acoustic shadow — complete absorption of ultrasound energy behind the stone, 3) Gravitational mobility — stone displacement with patient position change. This triad has >95% sensitivity and >98% specificity for gallstone diagnosis on US.
One or more hyperechoic structures in the gallbladder lumen with clean posterior acoustic shadow behind them. Stones settle gravitationally to the lowest point (fundus) and move with position change.
Report Sentence
A … mm hyperechoic structure with posterior acoustic shadow is seen in the gallbladder, consistent with gallstone.
WES (Wall-Echo-Shadow) complex: wall + echo + shadow seen together in a gallbladder packed with numerous stones. The lumen is completely filled with stones and no bile fluid is visible.
Report Sentence
WES complex is observed in the gallbladder fossa, indicating the gallbladder is completely filled with stones.
Hyperdense structures (calcified stones) in the gallbladder lumen on unenhanced CT. CT sensitivity is lower than US (75-80%) because pure cholesterol stones may be isodense and invisible.
Report Sentence
Hyperdense structures are seen in the gallbladder on unenhanced CT, consistent with calcified gallstones.
T2 hypointense filling defects within the gallbladder on T2-weighted MRI (or MRCP). Bile fluid is very bright on T2 and stones appear as dark filling defects against this bright background.
Report Sentence
T2 hypointense filling defects are seen in the gallbladder on T2-weighted MRI/MRCP, consistent with gallstones.
Gallstones together with biliary sludge. Sludge is low-echogenicity material that settles gravitationally in the gallbladder lumen and is frequently found together with stones.
Report Sentence
Biliary sludge is observed together with gallstones in the gallbladder.
Rim-calcified stones in the gallbladder on contrast-enhanced CT — low density center (cholesterol), high density periphery (calcium shell) pattern.
Report Sentence
Rim-calcified stones are seen in the gallbladder on CT.
Criteria
80% of gallstones are cholesterol-predominant. Yellow-green in color, single or few in number, usually large (>1 cm).
Distinct Features
May be isodense on CT and invisible — US is superior for diagnosis. T2 hypointense filling defect on MRCP.
Criteria
15-20% of stones. Calcium bilirubinate predominant. Black or brown. Associated with hemolysis, cirrhosis, or infection.
Distinct Features
More frequently hyperdense on CT (high calcium content). Black pigment stones tend to be small, numerous, and prismatic.
Criteria
Mixture of cholesterol + calcium components. Variable in size and number.
Distinct Features
Rim calcification on CT (outer calcium shell, inner cholesterol core) is the characteristic pattern.
Distinguishing Feature
Gallbladder polyps are attached to the wall and do not show gravitational mobility (immobile). There is no acoustic shadow behind polyps (unlike stones). Pedunculated polyps may show vascularity on Doppler.
Distinguishing Feature
Sludge is low-echogenicity material that does not create clean acoustic shadow (unlike stones). Sludge moves slowly with position change and forms a new layer.
Distinguishing Feature
Comet-tail artifact in adenomyomatosis arises from cholesterol crystals in intramural Rokitansky-Aschoff sinuses and is within the wall — unlike stones in the lumen. Comet-tail artifact is much shorter than acoustic shadow.
Distinguishing Feature
In porcelain gallbladder, calcification is in the wall (mural), while in luminal stones, calcification is within the stone. CT clearly shows this distinction — mural calcification vs luminal calcification.
Urgency
surveillanceManagement
conservativeBiopsy
Not NeededFollow-up
annualAsymptomatic gallstones do not require treatment — 80% remain asymptomatic throughout life. In symptomatic patients (biliary colic), elective laparoscopic cholecystectomy is standard treatment. Complications: acute cholecystitis, choledocholithiasis, acute pancreatitis, gallbladder carcinoma (rare). Biopsy is not needed — diagnosis is definitive with US. Dietary control (avoiding fatty foods) aids in symptom management but stone dissolution (ursodeoxycholic acid) is only considered for small cholesterol stones in patients unsuitable for surgery.
Cholelithiasis can cause biliary colic, acute cholecystitis, choledocholithiasis, and acute pancreatitis. Asymptomatic stones are generally observed. Symptomatic stones are treated with laparoscopic cholecystectomy.