title: The effect of liver iron deposition on hepatic apparent diffusion coefficient values in cirrhosis.
abstract: OBJECTIVE
  The purpose of this study was to assess the effect of hepatic iron deposition on apparent diffusion coefficient (ADC) values measured with single-shot echo-planar imaging (EPI) diffusion-weighted MRI (DWI) in patients with liver cirrhosis and in vitro.
  
  
  METHODS
  Fifty-two patients with liver cirrhosis who underwent breath-hold single-shot EPI DWI at 1.5 T before liver transplantation were retrospectively assessed. Estimated signal-to-noise ratio (SNRest) and ADC were measured in the right hepatic lobe (for b values of 50 and 500 s/mm2). SNRest and ADC were compared between patients stratified by pathologic iron grade using the Mann-Whitney test. Hepatic ADC values were correlated to T2* values using the Spearman correlation test in a subset of patients. In addition, a phantom consisting of solutions of varying iron concentrations was imaged with single-shot EPI DWI and T2* imaging, and iron concentration was correlated with ADC and T2*.
  
  
  RESULTS
  In phantoms, there was a decrease in ADC and T2* with increasing iron concentration (r=-0.95 and -0.92, respectively; p<0.05). Patients with hepatic siderosis had significantly lower SNRest and ADC compared with patients without siderosis (p<0.0001). SNRest at b=50 s/mm2 and b=500 s/mm2 and ADC had a significant negative correlation with pathologic iron grade (r=-0.67 to 0.77, p<0.0001). There was a significant correlation between liver T2* and ADC (r=0.83, p<0.0001).
  
  
  CONCLUSIONS
  Hepatic siderosis lowers liver ADC and should be taken into account when using ADC for diagnosing liver cirrhosis.
authors.affiliation: Department of Radiology, New York University Langone Medical Center, 550 First Ave, New York, NY 10016, USA. hersh.chandarana@nyumc.org
authors.forename: Hersh
authors.initials: H
authors.lastname: Chandarana
authors.forename: Richard K G
authors.initials: RK
authors.lastname: Do
authors.forename: Thais C
authors.initials: TC
authors.lastname: Mussi
authors.forename: Jens H
authors.initials: JH
authors.lastname: Jensen
authors.forename: Cristina H
authors.initials: CH
authors.lastname: Hajdu
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.forename: Bachir
authors.initials: B
authors.lastname: Taouli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008103:Liver Cirrhosis / Q000150:complications / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D012806:Siderosis / Q000150:complications / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
chemical_list: D007501:Iron