EUS, Evaluation of Gallbladder Lesions. Background. The diseases of the gallbladder are common. Transabdominal ultrasound is the preferred first-line radiographic exam of most gallbladder pathology. Endoscopic ultrasound, EUS, is a promising modality which is increasingly used in the evaluation of gallbladder or biliary duct lesions including microlithiasis and sludge in the gallbladder and bile duct. Certain gallbladder pathologies include gallbladder polyp, cysts, diagnosis, and staging of the gallbladder cancers. EUS can improve the diagnosis of gallbladder and bile duct lesions by providing high-resolution images due to close proximity of echo endoscope to the gallbladder and extrahepatic biliary tree. The advantage of EUS over transabdominal ultrasound is the ability to perform minimally invasive therapeutic interventions for some of gallbladder lesions. The aim of this video is to highlight the importance of EUS evaluation of certain gallbladder and bile duct lesions which could be missed on transabdominal ultrasound and to show endosonographic techniques for identification of these lesions. Cases. Gallbladder sludge ball. In this case, the patient presents with acute pancreatitis as intolerant of MRCP. EUS was performed to evaluate the bile duct. A large echo-dense structure is seen in the body of the gallbladder here. It is a sludge ball rather than a stone as there is no acoustic shadowing behind the sludge ball. The gallbladder is followed up to the neck and appears clear. The sludge ball is clearly mobile and the wall is not thickened, reassuring that there is no acute cholecystitis. The gallbladder can be traced to the common bile duct and pancreatic duct and back again demonstrating the so-called stack sign. Their lumens are clearly seen and remain unoccluded, suggesting that ERCP is not necessary prior to cholecystectomy due to biliary pancreatitis. Gallbladder layering sludge. In this case, we see a more classical appearing layering sludge that is clearly mobile with shaking of the EUS scope, demonstrating that it is not a gallbladder polyp, mass, or adenomyotosis. This is another classic example of layering sludge in the gallbladder with suspended sludge above it. The radial probe can also identify small amounts of sludge in the gallbladder as seen in this example. This case shows a 3.8 obstructing mass in the head of the pancreas leading to accumulation of dense heterogeneous hyperechoic sludge without shadowing leading back to the mass. This finding illustrates how gallbladder sludge can blend in with the background abdominal organs and demonstrates why following the common bile duct to the gallbladder is important. This is another case of peri-ambulary pancreatic mass leading to obstruction of the pancreatic duct and common bile duct. The area shown is distal to the obstructing mass and is easily mistaken for the gallbladder with its suspended sludge and debris as well as parallel hyperechoic linear structures, that is a biliary stent or two. But with careful inspection, the walls of the cystic duct and gallbladder can be visualized with a more typical appearance of the gallbladder with dense layering sludge. Mixed sludge and stones can be seen here in the gallbladder fundus and tracing down to the common bile duct just before it joins the pancreatic duct. Gallbladder polyp. In this case, you can see the non-shadowing polyploid engrossed into the gallbladder lumen. Multiple well-defined rounded polyps are seen here. These polyps are immobile with homogeneous echogenicity. These pedunculated gallbladder polyps with smooth surface are likely benign. Here is another case with idiopathic pancreatitis showing small punctate opacities through the gallbladder lumen with a starry sky appearance of suspended sludge. A small polyp, likely a cholesterol polyp, is adherent to the wall of the gallbladder can be seen. Gallstones. In this case, two large hyperechoic stones can be seen in the gallbladder. Acoustic shadow can be seen behind the stones. Sludge can be seen in between the stones pointed out with a red arrow. This case also shows a small polyp stuck on the inner surface of the gallbladder which can be differentiated from stones because of absence of acoustic shadow. This is another case of gallstones where multiple hyperechoic stones can be seen in the gallbladder with underlying acoustic shadows. Gallbladder calcification. This is a typical example of gallbladder calcification known as porcelain gallbladder. The gallbladder wall is diffusely calcified without much shadowing. Multiple irregular clumps of echoes are visible here. Moderate amount of layering sludge is seen here. Bile duct sludge. This patient has a 5 centimeter pancreatic head mass partially obstructing the common bile duct. With careful scanning of the EOS scope, a hyperechoic density is seen in the lumen of the common bile duct indicating CBD sludge. There is no acoustic shadow posterior to the sludge. Bile duct sludge. This patient has a 5 centimeter pancreatic head mass partially obstructing the common bile duct. Bile duct sludge ball. This is another case of pancreatic mass. The CBD is dilated to 12 millimeters with a clear mobile sludge ball rather than a stone seen in the lumen. Proximal scanning of EOS shows small amount of sludge in the lumen of the cystic duct. Bile duct stones. This case shows a dilated gallbladder filled with layering sludge. The gallbladder wall is thickened. The gallbladder can be traced down to the bile duct where a hyperdense stone partially occluded the lumen of the CBD. Cystic duct stone. In this case, the cystic duct is shown partially obstructed with multiple hyperdensities in the lumen. Acoustic shadows are seen under these densities indicating cystic duct stones. Here is another cystic duct stone. Endosonographic techniques. The EOS image orientation on screen was as follows. Monitor's right side corresponds to the cranial and left to the caudal end of the patient. Rotation of the echo endoscope is the most crucial aspect to gallbladder imaging. Majority of the movements are performed in a straight position of the echo endoscope except during EOS imaging from the first part of duodenum when the scope is in a J-shaped position. Proper right or left knob movements along with the in and out movement of the echo endoscope are utilized for adequate contact with the gastrointestinal wall for proper EOS imaging. Conclusions. EOS is an important new modality for the evaluation of gallbladder disease.

endoscopic ultrasound

gallbladder lesions

bile duct lesions

transabdominal ultrasound

gallbladder diseases