title: MRCP and MRI findings in 9 patients with autoimmune pancreatitis.
abstract: OBJECTIVE
  To evaluate magnetic resonance cholangiopancreatography (MRCP) findings in conjunction with magnetic resonance (MR) images in autoimmune pancreatitis (AIP) patients.
  
  
  METHODS
  Nine patients with AIP underwent MRI, MRCP, endoscopic retrograde cholangiopancreatography (ERCP), computed tomography, and ultrasonography. The MRCP and MR images taken before and after steroid therapy were reviewed and compared with other imaging modalities. The MRCP findings of the AIP cases were compared to those of 10 cases with carcinoma of the head of the pancreas.
  
  
  RESULTS
  On MRCP, the narrowed portion of the main pancreatic duct noted on ERCP was not visualized, while the non-involved segments of the main pancreatic duct were visualized. The degree of upstream dilatation of the proximal main pancreatic duct was milder than that seen in cases of pancreatic carcinoma. Stenosis or obstruction of the lower bile duct was detected in 8 patients. MR images showed enlargement of the pancreas with decreased signal intensity on T1-weighted MR images, increased signal intensity on T2-weighted MR images, and, in 3 patients, a hypointense capsule-like rim. After steroid therapy, the previously not visualized portion of the main pancreatic duct was seen, along with improvement of the bile duct stenosis. Pancreatic enlargement decreased, and the abnormal signal intensity on both T1- and T2-weighted MR images became isointense.
  
  
  CONCLUSIONS
  MRCP cannot differentiate irregular narrowing of the main pancreatic duct seen with AIP from stenosis of the main pancreatic duct seen with pancreatic carcinoma. However, MRCP findings in conjunction with MR imaging of pancreatic enlargement that shows abnormal signal intensity on T1- and T2-weighted MR images are useful in supporting a diagnosis of AIP.
authors.affiliation: Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bukyo-ku, Tokyo, Japan. kamisawa@cick.jp
authors.forename: Terumi
authors.initials: T
authors.lastname: Kamisawa
authors.forename: Pong-Yui
authors.initials: PY
authors.lastname: Chen
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Tu
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Naoto
authors.initials: N
authors.lastname: Egawa
authors.forename: Kouji
authors.initials: K
authors.lastname: Tsuruta
authors.forename: Atsutake
authors.initials: A
authors.lastname: Okamoto
authors.forename: Noriko
authors.initials: N
authors.lastname: Kamata
mesh_terms: D001327:Autoimmune Diseases / Q000175:diagnosis / Q000473:pathology*; D049448:Cholangiopancreatography, Magnetic Resonance; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology; D010195:Pancreatitis / Q000175:diagnosis / Q000473:pathology*