title: Timing of radiological improvement after steroid therapy in patients with autoimmune pancreatitis.
abstract: OBJECTIVE
  We retrospectively studied the timing of radiological improvement after steroid therapy in patients with autoimmune pancreatitis (AIP).
  
  
  METHODS
  Patients with AIP (n = 31) received steroids followed by diagnostic imaging within 1 month. Pancreatic swelling, pancreatic and bile duct features, and apparent diffusion coefficient (ADC) were compared before and after treatment. The period from treatment initiation to evaluation was divided into five phases: early phase (days 3-5), week 1 (days 6 and 7), week 2 (days 8-14), week 3 (days 15-21), and week 4 (days 22-28). Five gastroenterologists evaluated pancreatic swelling and duct features (good/intermediate/no response), and the "good response" rate (response rate) was calculated for each phase. In addition, pancreatic volumes were measured with a 3D workstation before and after treatment, and the percentage change in volume was calculated. ADC values were calculated in 14 patients.
  
  
  RESULTS
  The median ratio of pancreatic volume after relative to before treatment was 0.89, 0.79, 0.67, 0.59, and 0.47 for early phase, week 1, week 2, week 3, and week 4, respectively. The response rate of the pancreatic swelling was 37.5%, 57.1%, 83.3%, 100%, and 100%; response rate of the pancreatic duct was 0%, 20%, 75%, 75% and 100%; and response rate of the bile duct was 0%, 66.7%, 83.3%, 100%, and 80%. The ADC increased after treatment in all 14 patients, including the 7 patients evaluated in the early phase.
  
  
  CONCLUSIONS
  Evaluation of pancreatic swelling and duct features is recommended in week 2 and thereafter. The ADC increased soon after treatment initiation, suggesting its usefulness for evaluating early treatment responses.
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University , Hiroshima , Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Yukutake
authors.forename: Tamito
authors.initials: T
authors.lastname: Sasaki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Serikawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Minami
authors.forename: Akihito
authors.initials: A
authors.lastname: Okazaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishigaki
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Ishii
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kosaka
authors.forename: Teruo
authors.initials: T
authors.lastname: Mouri
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoshimi
authors.forename: Akinori
authors.initials: A
authors.lastname: Shimizu
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Tsuboi
authors.forename: Keizo
authors.initials: K
authors.lastname: Tanitame
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy*; D001652:Bile Ducts / Q000473:pathology*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D004487:Edema / Q000000981:diagnostic imaging / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000187:drug effects; D010179:Pancreas / Q000473:pathology*; D010183:Pancreatic Ducts / Q000473:pathology; D010195:Pancreatitis / Q000000981:diagnostic imaging / Q000188:drug therapy*; D011239:Prednisolone / Q000627:therapeutic use; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D000893:Anti-Inflammatory Agents; D011239:Prednisolone
keywords: apparent diffusion coefficient; autoimmune pancreatitis; diffusion-weighted imaging; steroid