title: Utility of diffusion-weighted MRI for differentiating acute from chronic cholecystitis.
abstract: To assess the use of diffusion-weighted imaging (DWI) for differentiating acute from chronic cholecystitis, in comparison with conventional magnetic resonance imaging (MRI) features.
  
  
  
  Liver MRI including DWI (b-values 0/500/1000s/mm(2) ) was performed at 1.5T ≤30 days before cholecystectomy in 83 patients with abdominal pain. Two radiologists assessed cases for conventional (gallstones, wall thickening, pericholecystic fluid, pericholecystic fat changes, gallbladder distension, pericholecystic liver enhancement, mural T2 -hyperintensity, mural hyperenhancement, mural striations, abscess, intraluminal membranes, and mural defect) and DWI (increased mural signal on high b-value images, visually low apparent diffusion coefficient [ADC], and ADC values) features.
  
  
  
  Acute cholecystitis was present in 43%; chronic cholecystitis was present in 57%. Nine of 12 conventional features were more frequent in acute cholecystitis for both readers (P ≤ 0.003). Increased mural signal on high b-value images was more frequent (P < 0.001) in acute than chronic cholecystitis for R1 (92% vs. 32%) and R2 (83% vs. 30%). Sensitivity and specificity of increased signal on high b-value images were: R1, 92%/68%; R2, 83%/70%. Visually low ADC was more frequent in acute cholecystitis for R2 (P < 0.001) but not R1 (P = 0.406); ADC values were not different between groups for either reader (P = 0.104-0.139). Among conventional and DWI features, only increased signal on high b-value DWI was independently associated with acute cholecystitis for both readers (P = 0.006-0.012).
  
  
  
  Visually increased mural signal on high b-value DWI was highly sensitive and moderately specific for acute cholecystitis, being an independent predictor relative to conventional features for both readers. Although requiring larger studies, DWI (particularly the high b-value images) may have additive value relative to conventional MRI-suspected acute cholecystitis. J. Magn. Reson. Imaging 2016;44:89-97.
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Annie
authors.initials: A
authors.lastname: Wang
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Alampady K
authors.initials: AK
authors.lastname: Shanbhogue
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Diane
authors.initials: D
authors.lastname: Dunst
authors.affiliation: Department of Pathology, NYU School of Medicine, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Cristina H
authors.initials: CH
authors.lastname: Hajdu
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Rosenkrantz
mesh_terms: D000208:Acute Disease; D041881:Cholecystitis, Acute / Q000000981:diagnostic imaging*; D002908:Chronic Disease; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
keywords: MRI; apparent diffusion coefficient; cholecystitis; diffusion-weighted imaging; gallbladder