From the Guidelines
To rule out chronic pancreatitis, the most recommended diagnostic test is Endoscopic Ultrasound (EUS), as it is considered the most sensitive imaging test for early chronic pancreatitis, according to the most recent guidelines 1. When evaluating for chronic pancreatitis, several diagnostic approaches can be considered, including:
- Pancreatic imaging studies such as computed tomography (CT) scans, magnetic resonance imaging (MRI), and magnetic resonance cholangiopancreatography (MRCP) to detect structural changes like pancreatic calcifications, ductal dilation, and atrophy.
- Endoscopic retrograde cholangiopancreatography (ERCP) for detailed visualization of the pancreatic ducts, though it is more invasive and typically reserved for therapeutic purposes.
- Functional tests like fecal elastase-1 measurement to assess exocrine pancreatic function, with levels below 200 μg/g suggesting pancreatic insufficiency.
- Blood tests for pancreatic enzymes, though these may be normal in chronic pancreatitis. The choice of test may depend on local expertise and availability, with MRI/MRCP being a reasonable complementary or alternative test to EUS 1. It's worth noting that while ERCP has been considered a "gold standard" for diagnosing chronic pancreatitis due to its ability to detect abnormal duct morphology, its invasive nature and the availability of less invasive yet highly sensitive tests like EUS and MRCP have shifted the preference towards these modalities for initial diagnostic purposes 1.
From the Research
Tests to Rule Out Chronic Pancreatitis
To diagnose or rule out chronic pancreatitis, several tests can be utilized, focusing on both the functional and structural aspects of the pancreas. These include:
- Imaging procedures:
- Endoscopic ultrasound
- Magnetic resonance cholangiopancreatography (MRCP)
- Magnetic resonance imaging (MRI)
- Computed Tomography (CT) scans 2
- Functional testing:
- Secretin-pancreozymin test: Sensitive for diagnosing chronic pancreatitis, especially in cases with inconclusive morphological findings 3
- Endoscopic test: Useful for detecting functional impairments in the pancreas 3
- Quantification of the coefficient of fat absorption (CFA) and the (13)C-mixed triglyceride breath test: Limited to diagnosing exocrine pancreatic insufficiency with maldigestion 3
- Faecal elastase and chymotrypsin: Useful for detecting reduction of pancreatic secretion and monitoring patients' compliance to enzyme replacement therapy 3
- Other tests:
- Fecal fat analysis
- Serum trypsin
- The cholecystokinin (CCK) stimulation test
- The combined secretin-CCK stimulation test
- The intraductal and endoscopic secretin stimulation tests
- Functional magnetic resonance imaging of the pancreas after secretin stimulation 4
- Measurement of pancreatic enzymes in biological fluids, including basal amylase and/or lipase in blood, and evocative tests like the pancreozymin and secretin test 5
Limitations and Considerations
It's important to note that no single test is universally applicable or definitive for all clinical situations 4. The choice of test depends on the stage of the disease, patient tolerance, and availability of the tests. Additionally, some tests, such as the Lundh test, N-benzoyl-tryosyl para-aminobenzoic acid (NBT-PABA) test, pancreolauryl test, and amino acid consumption test, are no longer useful or available for clinical practice 3.
Diagnostic Criteria and Reporting Standards
For chronic pancreatitis, there is a need for standardized diagnostic criteria and reporting standards, especially for cross-sectional imaging findings 2. Features such as calcifications, parenchymal T1 signal changes, focal or diffuse gland atrophy, and irregular contour of the gland are clinically applied but lack universal standards. Efforts like those by the Consortium for the Study of Chronic Pancreatitis, Diabetes, and Pancreatic Cancer aim to address these gaps 2.