title: Evaluation of hepatic lesions and hepatic parenchyma using diffusion-weighted echo-planar MR with three values of gradient b-factor.
abstract: OBJECTIVE
  To determine whether diffusion-weighted echo-planar (EP) MR images with very small, small, and large gradient b-factors are useful in evaluating hepatic lesions and hepatic parenchyma.
  
  
  METHODS
  Approximate values of the apparent diffusion coefficients for diffusion (D) and for flowing spins (D*) for 96 hepatic lesions (26 hepatocellular carcinomas [HCCs], 28 metastases, 26 hemangiomas, and 16 cysts) and the non-lesion-bearing regions of parenchyma in 78 livers (50 noncirrhotic and 28 cirrhotic) were calculated from EP images (modified for gradient b-factors of 3, 50, and 300 second/mm(2)).
  
  
  RESULTS
  Liver cysts and noncirrhotic livers showed statistically higher mean D* values than HCCs, hemangiomas, metastases, and cirrhotic livers (P < 0.05 on Scheffé post hoc analysis). Liver cysts showed statistically higher mean D values than HCCs, metastases, noncirrhotic livers, and cirrhotic livers (P < 0.05). Liver hemangiomas showed statistically higher mean D values than HCCs, noncirrhotic livers, and cirrhotic livers (P < 0.05).
  
  
  CONCLUSIONS
  The D* value in addition to the D value may be useful for evaluating the nature of diffusion and flowing spins in hepatic lesions and hepatic parenchyma.
authors.affiliation: Department of Diagnostic Radiology, Gunma University Hospital, Maebashi, Gunma, Japan. pwd8ja227h@md.point.ne.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Moteki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Horikoshi
mesh_terms: D003110:Colonic Neoplasms / Q000473:pathology; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005355:Fibrosis / Q000175:diagnosis* / Q000473:pathology*; D006801:Humans; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology; D015233:Models, Statistical; D009362:Neoplasm Metastasis; D019047:Phantoms, Imaging; D015203:Reproducibility of Results