Ultrasound examination of the gallbladder using grayscale B-mode ultrasonography (transabdominal approach) demonstrates two echogenic foci within the gallbladder lumen. Both features are dependent on the gallbladder, implying intraluminal calculi rather than extrinsic objects. Each lesion casts a posterior acoustic shadow, a hallmark of gallstones, and their appearance distinguishes calcified cholesterol stones from gallbladder polyps, which typically lack shadowing. The stones measure over 2 millimeters in diameter, consistent with cholelithiasis and enabling reliable detection by ultrasound. The gallbladder wall appears without significant thickening, and there is no overt pericholecystic fluid evident on this image, arguing against acute cholecystitis at the time of imaging. The study highlights the classic sonographic criteria for gallstone disease: echogenic mobile calculi with clean shadowing, gravity-dependent location, and recognition of potential sludge in the gallbladder lumen. This imaging feature set supports clinical decisions regarding symptomatic biliary colic, risk stratification for complications, and surgical planning such as cholecystectomy. In differential considerations, gallbladder polyps or sludge can mimic stones; however, shadowing and mobility aid differentiation. Overall, ultrasound remains the initial modality of choice for suspected biliary pathology due to safety, accessibility, and high diagnostic yield. Correlative clinical data and laboratory tests further refine management decisions. Guiding patient-specific treatment options.

This diagnostic image is a 2D grayscale abdominal ultrasound focusing on the gallbladder (labeled 'GB'). The gallbladder is visualized as an anechoic (black) fluid-filled sac. Within the dependent portion of the gallbladder lumen, there are multiple hyperechoic (bright) mobile structures consistent with cholelithiasis (gallstones). These stones demonstrate posterior acoustic shadowing, a hallmark diagnostic feature where the sound waves are blocked by the dense stones. The gallbladder wall appears thin and regular, without obvious evidence of wall thickening, pericholecystic fluid, or other signs of acute cholecystitis. In the clinical context of situs inversus totalis, this ultrasound identifies the gallbladder positioned on the left side of the upper abdomen. This visual serves as a primary diagnostic tool for evaluating biliary colic and symptomatic cholelithiasis.