What is the gold standard test to diagnose chronic pancreatitis?

From the Guidelines

The gold standard test to diagnose chronic pancreatitis is MRI with MRCP protocol, as it is the recommended investigation of choice according to the 2018 guidelines for the investigation of chronic diarrhoea in adults by the British Society of Gastroenterology 1. This recommendation is based on the high sensitivity and specificity of MRI with MRCP protocol in detecting characteristic changes of chronic pancreatitis, such as ductal strictures, dilations, and irregularities. The use of MRI with MRCP protocol is preferred over other imaging modalities, such as CT, due to its higher sensitivity and ability to provide detailed images of the pancreatic duct system. Some key points to consider when using MRI with MRCP protocol for diagnosing chronic pancreatitis include:

• The test is non-invasive and does not carry the risks associated with ERCP, such as post-procedure pancreatitis, bleeding, and infection.
• MRI with MRCP protocol can detect early changes of chronic pancreatitis, allowing for early diagnosis and treatment.
• The test can be used to monitor disease progression and response to treatment. However, it is essential to note that ERCP is still considered the reference standard for diagnosing chronic pancreatitis, particularly in cases where therapeutic intervention is required or when other tests are inconclusive 1. In clinical practice, the choice of diagnostic test will depend on the individual patient's needs and the availability of resources. Some key considerations when choosing a diagnostic test for chronic pancreatitis include:
• The patient's symptoms and medical history
• The availability of imaging modalities and expertise
• The potential risks and benefits of each test
• The need for therapeutic intervention.

From the Research

Diagnosis of Chronic Pancreatitis

The diagnosis of chronic pancreatitis can be challenging, and various tests are used to confirm the diagnosis.

• Hormone-stimulated pancreatic function tests (PFTs) are considered the gold standard for measuring pancreatic exocrine function 2.
• PFTs involve the administration of intravenous secretin or cholecystokinin, followed by collection and analysis of pancreatic secretions.
• The secretin endoscopic pancreatic function test (ePFT) has demonstrated good sensitivity and specificity compared with various reference standards, including the "Dreiling tube" secretin PFT, endoscopic ultrasound, and surgical histology 2.

Role of Endoscopic Ultrasound

Endoscopic ultrasound (EUS) is a valuable tool in the diagnosis of chronic pancreatitis.

• EUS can detect abnormalities suggestive of chronic pancreatitis in the pancreatic parenchyma and ductal system which are not visible on any other imaging modality 3.
• The Rosemont classification aims to standardize the criteria for diagnosing chronic pancreatitis by EUS, assigning different values to different features 4, 5.
• A combined use of endoscopic function test and EUS has increased the diagnostic yield 4.

Limitations and Challenges

Despite the advances in diagnostic techniques, there are still limitations and challenges in diagnosing chronic pancreatitis.

• The diagnosis of chronic pancreatitis at an early stage is a clinical challenge 3.
• The presence of chronic pancreatitis can reduce the diagnostic ability of EUS-FNA for small pancreatic lesions 6.
• The diagnostic significance of patients with fewer criteria found on EUS is currently unclear, particularly when other diagnostic tests such as ERCP and function testing are normal 3.