Title: Can MRCP Replace ERCP for the Diagnosis of Autoimmune Pancreatitis?
Abstract: Background and Aim: Autoimmune pancreatitis (AIP) is currently diagnosed based on a combination of clinical, laboratory, and imaging studies. Since AIP responds dramatically to steroid therapy, it is most important to differentiate AIP from pancreatic cancer to avoid unnecessary surgery. Irregular narrowing of the main pancreatic duct is a characteristic finding in AIP; it is useful for differentiating AIP from pancreatic cancer stenosis. In many pancreatobiliary diseases, magnetic resonance cholangiopancreatography (MRCP) is replacing diagnostic endoscopic retrograde cholangiopancreatography (ERCP). This study evaluated the usefulness of MRCP for the diagnosis of AIP and assessed whether MRCP could replace ERCP for diagnosing AIP. Methods: The MRCP and ERCP findings of 20 AIP patients (diffuse (n = 6); segmental in the head (n = 4), body (n = 3), and tail (n = 2); two skipped in the head and body or tail (n = 5)) were compared. Results: On ERCP, the length of the narrowed portion of the main pancreatic duct was longer than 3 cm in 18 patients, while it was 2 cm in length in 2 patients. Stenosis of the bile duct was detected in 14 patients, and all of them showed stenosis of the lower bile duct. Furthermore, 2 patients also had stenosis of the intrahepatic bile duct. After steroid therapy, both narrowing of the main pancreatic duct and stenosis of the bile duct improved markedly in all 18 patients. On MRCP of patients with diffuse-type AIP, the entire main pancreatic duct was non-visualized in 3 patients and incompletely visualized in 3 patients. On MRCP of patients with segmental-type AIP, the narrowed portion of the main pancreatic duct was not visualized, while the non-involved segments of the pancreatic duct were visualized. Although upstream dilatation of the proximal main pancreatic duct was detected in the 7 segmental-type AIP patients, the degree of dilatation was milder than that in pancreatic cancer patients. In patients with skipped-type AIP, only skipped narrowed lesions were not visualized on MRCP. Stenosis of the lower or intrahepatic bile duct was similar on MRCP and ERCP. After steroid therapy, the non-visualized main pancreatic duct became visualized on MRCP. Conclusions: MRCP cannot replace ERCP for the diagnosis of AIP, since narrowing of the main pancreatic duct in AIP was not visualized on MRCP. MRCP findings of segmental or skipped non-visualized main pancreatic duct accompanied by a less dilated upstream main pancreatic duct may suggest the presence of AIP. MRCP is useful for following AIP patients.
Publication Year: 2008
Publication Date: 2008-04-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 3
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot