title: Prospective evaluation of nonenhanced MR imaging in acute pancreatitis.
abstract: OBJECTIVE
  To compare the value of nonenhanced (NE) magnetic resonance imaging (MRI) (NE-MRI) with contrast-enhanced (CE) computed tomography (CT) (CE-CT) scan in assessing acute pancreatitis (AP) and in evaluating the severity index (SI) with clinical outcome.
  
  
  METHODS
  Patients with AP were prospectively investigated by CE-CT scan and NE-MRI on admission. MRI was performed with fat-saturated T1-weighted imaging, T2-weighted imaging, and MR cholangiopancreatography (MRCP). Balthazar's grading system was used to evaluate the NE-MRI severity index (CTSI, MRISI) and it was compared to the clinical outcome.
  
  
  RESULTS
  A total of 90 patients (median age = 55 years) were included in the study. AP was of biliary etiology in 37 patients (41%). On admission, AP was assessed as grade III by CTSI in four patients (4%), whereas 19 patients were classified grade III by MRISI. The coefficient correlation between CTSI and MRISI was good, with r = 0.6 (P < 0.001). Considering CE-CT scan as the gold standard, sensitivity (Sn), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of NE-MRI for detecting severe AP based on imaging criteria were 100%, 82.6%, 100%, and 21%, respectively. NE-MRI discriminates normal pancreatic parenchyma from edema and necrosis with a correlation between morbidity (P < 0.008).
  
  
  CONCLUSIONS
  NE-MRI seems to be a reliable method of staging AP severity in comparison to CE-CT scan.
authors.affiliation: Hospices Civils de Lyon, Département d'imagerie digestive, Hôpital E. Herriot, Lyon, France.
authors.forename: Loic
authors.initials: L
authors.lastname: Viremouneix
authors.forename: Olivier
authors.initials: O
authors.lastname: Monneuse
authors.forename: Guillaume
authors.initials: G
authors.lastname: Gautier
authors.forename: Laurent
authors.initials: L
authors.lastname: Gruner
authors.forename: Roch
authors.initials: R
authors.lastname: Giorgi
authors.forename: Bernard
authors.initials: B
authors.lastname: Allaouchiche
authors.forename: Frank
authors.initials: F
authors.lastname: Pilleul
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004487:Edema / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010179:Pancreas / Q000473:pathology; D010195:Pancreatitis / Q000175:diagnosis / Q000473:pathology*; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods