title: Diagnostic Performance of Contrast-Enhanced MRI With Secretin-Stimulated MRCP for Non-Calcific Chronic Pancreatitis: A Comparison With Histopathology.
abstract: OBJECTIVE
  Diagnosis of non-calcific chronic pancreatitis (NCCP) in patients presenting with chronic abdominal pain is challenging and controversial. Contrast-enhanced magnetic resonance imaging (MRI) with secretin-stimulated MRCP (sMRCP) offers a safe and noninvasive modality to diagnose mild CP, but its findings have not been correlated with histopathology. We aimed to assess the correlation of a spectrum of MRI/sMRCP findings with surgical histopathology in a cohort of NCCP patients undergoing total pancreatectomy with islet autotransplantation (TPIAT).
  
  
  METHODS
  Adult patients undergoing TPIAT for NCCP between 2008 and 2013 were identified from our institution's surgery database and were included if they had MRI/sMRCP within a year before surgery. Histology was obtained from resected pancreas at the time of TPIAT by wedge biopsy of head, body, and tail, and was graded by a gastrointestinal pathologist who was blinded to the imaging features. A fibrosis score (FS) of 2 or more was considered as abnormal, with FS ≥6 as severe fibrosis. A multivariate regression analysis was performed for MRI features predicting fibrosis, after taking age, sex, smoking, alcohol, and body mass index (BMI) into consideration. A quantitative receiver operating characteristic (ROC) curve analysis was performed and Spearman rank correlation coefficient (r) was calculated.
  
  
  RESULTS
  Fifty-seven patients (females=49, males=8) with NCCP and MRI/sMRCP were identified. ROC curve analysis showed that two or more MRI/sMRCP features provided the best balance of sensitivity (65%), specificity (89%), and accuracy (68%) to differentiate abnormal (FS≥2) from normal pancreatic tissue. Two or more features provided the best cutoff (sensitivity 88%, specificity 78%) for predicting severe fibrosis (FS≥6). There was a significant correlation between the number of features and severity of fibrosis (r=0.6, P<0.0001). A linear regression after taking age, smoking, and BMI into consideration showed that main pancreatic duct irregularity, T1-weighted signal intensity ratio between pancreas and paraspinal muscle, and duodenal filling after secretin injection to be significant independent predictors of fibrosis.
  
  
  CONCLUSIONS
  A strong correlation exists between MRI/sMRCP findings and histopathology of NCCP.
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Guru
authors.initials: G
authors.lastname: Trikudanathan
authors.affiliation: Center for Diagnostic Imaging, Minneapolis, Minnesota, USA.
authors.forename: Sidney P
authors.initials: SP
authors.lastname: Walker
authors.affiliation: Division of Gastroenterology, St Louis University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Satish
authors.initials: S
authors.lastname: Munigala
authors.affiliation: Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Spilseth
authors.affiliation: Department of Internal Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Malli
authors.affiliation: Department of Pathology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Han
authors.affiliation: The Schulze Diabetes Institute, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Melena
authors.initials: M
authors.lastname: Bellin
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Srinath
authors.initials: S
authors.lastname: Chinnakotla
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Ty
authors.initials: T
authors.lastname: Dunn
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Pruett
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Beilman
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Vega Peralta
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Mustafa A
authors.initials: MA
authors.lastname: Arain
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Amateau
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Schwarzenberg
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Shawn
authors.initials: S
authors.lastname: Mallery
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Attam
authors.affiliation: Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Martin L
authors.initials: ML
authors.lastname: Freeman
mesh_terms: D000328:Adult; D049448:Cholangiopancreatography, Magnetic Resonance; D003287:Contrast Media; D005260:Female; D005355:Fibrosis; D005765:Gastrointestinal Agents; D006801:Humans; D016381:Islets of Langerhans Transplantation; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology*; D010180:Pancreatectomy; D050500:Pancreatitis, Chronic / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012633:Secretin; D055815:Young Adult
chemical_list: D003287:Contrast Media; D005765:Gastrointestinal Agents; D012633:Secretin