Diagnosis of early-stage chronic pancreatitis by secretin-enhanced magnetic resonance cholangiopancreatography

Abstract

A diagnostic means of detecting chronic pancreatitis at an early stage, when the disease is still reversible, needs to be developed. Magnetic resonance cholangiopancreatography (MRCP) has recently been evolving as an important tool for the evaluation of chronic pancreatitis. In patients with moderate chronic pancreatitis, the pancreatic parenchyma displays an abnormal enhancement pattern on T1-weighted sequences after gadolinium administration. The presence of a signal intensity ratio of <1.7 in the arterial phase and/or delayed peak enhancement after contrast administration has a sensitivity of 92% and a specificity of 75% for the demonstration of early chronic pancreatitis. The secretin-induced pancreatic T2 signal intensity changes are significantly reduced in patients with a mild exocrine pancreatic insufficiency as compared with healthy volunteers. MRCP visualizes fluid in the pancreatic and biliary ducts as high signal intensity on heavily T2-weighted sequences. However, visualization of normal or minimally dilated pancreatic ducts by MRCP is more challenging because of their small size. Secretin administration stimulates fluid and bicarbonate secretion by the exocrine pancreas; consequently, it improves the pancreatic duct and side-branch delineation and allows an evaluation of the exocrine pancreatic function. Side-branch ectasia, mild ductal dilatation with loss of the normal gentle taper, and mural irregularities are the pathognomonic MRCP features of early-stage chronic pancreatitis. Through measurement of the duodenal filling, secretin-MRCP allows quantitative assessment of the exocrine pancreatic function, even in patients with a mild exocrine insufficiency. The morphology of the pancreatic ducts, particularly in the early stages, does not always correlate with the functional status. MRCP permits visualization of the ductal changes and furnishes functional information on the pancreas; this combination may enhance its diagnostic accuracy so that MRCP can become a valuable diagnostic means in early-stage chronic pancreatitis.

Italian consensus guidelines for chronic pancreatitis

“…Furthermore MRCP can be acquired dynamically during intravenous secretin administration in order to non-invasively obtain morphologic and functional information [133][134][135][136][137][138][139].…”

Secretin-enhanced Magnetic Resonance Cholangiopancreatography in Pancreatic Insufficient and Pancreatic Sufficient Cystic Fibrosis Patients

“…The main advantage that SE-MRCP holds over other imaging methods is improved visualization of the pancreatic ductal system [26]. This increases its diagnostic potential in early and mild pancreatitis [27], as well as in congenital abnormalities, such as the pancreas divisum [28]. Different teams elaborated protocols in which SE-MRCP is used to assess the pancreatic fluid volume [29][30][31][32][33], which provides additional information on exocrine pancreatic function.…”

Chronic pancreatitis. Multicentre prospective data collection and analysis by the Hungarian Pancreatic Study Group

“…MRCP is a non-invasive imaging test, which does not use ionizing radiation and provides an excellent image of the main pancreatic duct, with sensitivity of 88% and specificity of 98% [51]. Secretin-enhanced MRCP allows for a quantitative assessment of exocrine pancreatic function by measuring the duodenal filling [52] and provides a more accurate way to identify small-duct disease in mild chronic pancreatitis [53]. The Hungarian Pancreatic Study Group (HPSG) prepared an evidence-based guideline for CP, which does not recommend the use of the ERCP as a diagnostic tool because of its morbidity and mortality rates.…”