From the Guidelines
For suspected cholangitis, the initial imaging study of choice is an abdominal ultrasound with specific attention to the biliary system, as recommended by the most recent guidelines 1. This non-invasive test can identify biliary dilation, gallstones, and some obstructing lesions. The use of abdominal ultrasound as the initial diagnostic imaging modality is supported by the 2024 clinical practice guideline update by the Infectious Diseases Society of America on complicated intra-abdominal infections, which suggests its use in non-pregnant adults with suspected acute cholecystitis or acute cholangitis 1. If ultrasound results are inconclusive or additional information is needed, magnetic resonance cholangiopancreatography (MRCP) should be ordered next as it provides detailed images of the biliary and pancreatic ducts without radiation exposure. Some key points to consider when evaluating suspected cholangitis include:
- The importance of prompt identification and treatment to prevent serious complications like sepsis
- The role of imaging studies in identifying the underlying cause of cholangitis, which typically results from biliary obstruction
- The potential use of other imaging modalities, such as CT with contrast, if ultrasound is unavailable or if there are concerns about complications like abscesses or perforation. In urgent situations where intervention may be immediately necessary, endoscopic retrograde cholangiopancreatography (ERCP) serves as both a diagnostic and therapeutic tool, allowing for direct visualization of the biliary tree and immediate intervention such as stone removal or stent placement 1.
From the Research
Imaging Options for Suspected Cholangitis
When suspecting cholangitis, the choice of imaging is crucial for diagnosis and management. The following options are available:
- Abdominal ultrasound: quickly explores the biliary tract but has poor diagnostic capacities, especially in non-gallstone obstruction 2
- Magnetic Resonance Cholangiopancreatography (MRCP): has excellent diagnostic capacities 2, 3
- Endoscopic Ultrasound (EUS): also has excellent diagnostic capacities 2, 3
- Computed Tomography (CT) scan: has intermediate diagnostic capacities and is more widely available 2
- Endoscopic Retrograde Cholangiography (ERC): can be used as both a diagnostic and therapeutic tool 3, 4
Considerations for Imaging Selection
The selection of imaging modality depends on the clinical suspicion, availability, and patient's condition. It is essential to note that:
- Bacteriological sampling through blood cultures and bile cultures is essential for diagnosis and management 2
- The presence of a biliary stent is a risk factor for infections by multidrug-resistant pathogens 2
- Endoscopic or radiological biliary drainage is a crucial management component, along with antimicrobial therapy 2, 4