The Diagnosis of Autoimmune Pancreatitis Using Endoscopic Ultrasonography

Autoimmune pancreatitis (AIP) is characterized by enlargement of the pancreas and irregular narrowing of the main pancreatic duct. It is often associated with IgG4-related sclerosing cholangitis (IgG4-SC), in which the bile duct narrows. Although characteristic irregular narrowing of the pancreatic duct caused by endoscopic retrograde cholangiopancreatography is noted in AIP, it is difficult to differentiate between localized AIP and pancreatic carcinoma based on imaging of the pancreatic duct. While stenosis of the bile duct in IgG4-SC is characterized by longer-length stenosis than in cholangiocarcinoma, differentiation based on bile duct imaging alone is challenging. Endoscopic ultrasound (EUS) can characterize hypoechoic enlargement of the pancreas or bile duct wall thickening in AIP and IgG4-SC, and diagnosis using elastography and contrast-enhanced EUS are being evaluated. The utility of EUS-guided fine needle aspiration for the histological diagnosis of AIP has been reported and is expected to improve diagnostic performance for AIP. Findings in the bile duct wall from endoscopic retrograde cholangiopancreatography followed by intraductal ultrasonography are useful in differentiating IgG4-SC from cholangiocarcinoma. Diagnoses based on endoscopic ultrasonography play a central role in the diagnosis of AIP.

Modern imaging modalities for diseases associated with obstructive jaundice syndrome

Obstructive jaundice (OJ) is a syndrome characterized by bile staining of the skin, mucous membranes, and sclera as a complication of pathological processes that lead to disruption of the bile ducts at various levels of the biliary tract. Obstructive jaundice represents various diseases with different onset, course, and outcome, as well as etiology, which implies the difficulties of the diagnostic process. Identification of a cholestasis cause and treatment of patients with OJ remain urgent and difficult tasks due to the steady rise in diseases of the hepatopancreatoduodenal zone (HPDZ) and the high frequency of diagnostic errors. The latter can lead to the progression of liver failure, as well as to the development of severe complications, which, in turn, are fatal. A significant role in detecting HPDZ pathology belongs to the radiological methods of studies, such as transabdominal ultrasonography (TUS), endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC), endoscopic ultrasound (EUS), intraductal ultrasonography (IDUS), magnetic resonance cholangiopancreatography (MRCP), helical computed tomography (hCT), and helical CT cholangiography (hCT-CG). However, it should be noted that, as of today, there is no well-established conventional radiological algorithm for determining the causes of biliary obstruction. This, in turn, leads to repeated or sequential inefficient administration of all possible methods of visualization, complicating the diagnostic algorithm. In this regard, it is advisable to perform an in-depth study of the Russian and foreign literature sources, highlighting the problem of an early and highly effective diagnostics of the causes of biliary obstruction in patients with OJ.