Biliary stasis refers to the slowing or cessation of normal bile flow, which can occur within the gallbladder or the bile duct system. When bile sits stagnant, its components can begin to crystallize and form a thick, semisolid material called biliary sludge, which appears on ultrasound as low-level echoes that layer in the dependent portion of the gallbladder and shift with changes in patient position. Biliary stasis commonly occurs in patients who are fasting for prolonged periods, those receiving total parenteral nutrition, or during critical illness. While sludge itself can resolve, it is considered a precursor to gallstone formation and can sometimes cause symptoms similar to gallstones.
Sonography Term