Modern imaging of cholangitis

Abstract

Cholangitis refers to inflammation of the bile ducts with or without accompanying infection. When intermittent or persistent inflammation lasts six months or more, the condition is classified as chronic cholangitis. Otherwise, it is considered an acute cholangitis. Cholangitis can also be classified according to the inciting agent, e.g., complete mechanical obstruction, which is the leading cause of acute cholangitis, longstanding partial mechanical blockage, or immune-mediated bile duct obliteration damage that results in chronic cholangitis. The work-up for cholangitis is based upon medical history, clinical presentation, and initial laboratory tests. Whereas ultrasound is the first-line imaging modality used to identify bile duct dilatation in patients with colicky abdominal pain, cross-sectional imaging is preferable when symptoms cannot be primarily localized to the hepatobiliary system. Computed tomography (CT) is very useful in oncologic, trauma, or postoperative patients. Otherwise, magnetic resonance cholangiopancreatography (MRCP) is the method of choice to diagnose acute and chronic biliary disorders, providing an excellent anatomic overview and, if gadoxetic acid is injected, simultaneously delivering morphological and functional information about the hepatobiliary system. If brush cytology, biopsy, assessment of the prepapillary common bile duct (CBD), stricture dilatation, or stenting is necessary, then endoscopic ultrasound (EUS) and/or retrograde cholangiography (ERC) are performed. Finally, when the pathologic duct is inaccessible from the duodenum or stomach, percutaneous transhepatic cholangiography (PTC) is an option. The pace of the work-up depends upon the severity of cholestasis on presentation. Whereas sepsis, hypotension, and/or Charcot’s triad warrant immediate investigation and management, chronic cholestasis can be electively evaluated. This overview article will cover the common cholangitides, emphasizing our clinical experience with the chronic cholestatic liver diseases.

Predictive factors for developing acute cholangitis due to choledocholithiasis

“…In patients with acute cholangitis, the pressure in the bile duct tends to be high. When the pressure in the bile duct rises to a certain level, the intercellular structure of the hepatocytes and the blood bile duct barrier may be destroyed, followed by patchy necrosis of hepatocytes, cholestasis and changes in liver function [21]. In this study, AST and ALP were found to be independent risk factors for developing acute cholangitis.…”

A multi‐institutional study designed by members of Tokyo Guidelines (TG) Core Meeting to elucidate the clinical characteristics and pathogenesis of acute cholangitis after bilioenteric anastomosis and biliary stent insertion with a focus on biliary obstruction: Role of transient hepatic attenuation difference (THAD) and pneumobilia in improving TG diagnostic performance

“…It is problematic that dynamic CT is required to obtain THAD findings, which is not a test that can be routinely performed in all centers and patients. Several findings regarding the plain magnetic resonance imaging (MRI) in AC (periportal abnormal intensity, high intensity in the liver parenchyma on T2 weighted images and so on) have been reported 24,25 . These MRI findings might be useful as an alternative for patients who cannot undergo dynamic CT; however, data regarding the MRI findings were not collected in the present study.…”

“…Several findings regarding the plain magnetic resonance imaging (MRI) in AC (periportal abnormal intensity, high intensity in the liver parenchyma on T2 weighted images and so on) have been reported. 24,25 These MRI findings might be useful as an alternative for patients who cannot undergo dynamic CT; however, data regarding the MRI findings were not collected in the present study. It is known that THAD occur in other conditions not associated with AC such as sepsis, 26 septic thrombophlebitis, 27 liver trauma including vascular injury, 28 arterial-portal shunt and portal venous stenosis, 29 so that THAD may not necessarily be specific to AC.…”

Imaging of Benign Biliary Tract Disease

“…Acute cholangitis (AC) occurs when biliary stenosis elevates pressure within the biliary system and causes spillover of bile and infection into the systemic circulation. 25,26 The Tokyo guidelines are useful for diagnosis (including imaging) and management of AC. 27 Ultrasound may show dilated biliary radicles and CBD and may also show the cause of obstruction.…”

“…Portal vein thrombosis may occur in patients with cholangitis. 25,26 Treatment consists of removal of cause of obstruction and/or biliary drainage along with appropriate antibiotic therapy (►Fig. 5).…”