title: Diffusion coefficients in abdominal organs and hepatic lesions: evaluation with intravoxel incoherent motion echo-planar MR imaging.
abstract: OBJECTIVE
  To determine the true diffusion coefficients of abdominal organs and hepatic lesions with intravoxel incoherent motion (IVIM) echo-planar magnetic resonance (MR) imaging.
  
  
  METHODS
  Seventy-eight patients suspected of having hepatic lesions were examined with IVIM echo-planar MR imaging at 1.5 T. There were 77 hepatic masses (27 hepatocellular carcinomas, 10 metastatic tumors, eight hemangiomas, and 32 cysts) in the 78 patients. The true diffusion coefficient D and the perfusion fraction f were calculated and compared with the apparent diffusion coefficient (ADC).
  
  
  RESULTS
  Specific values of D were found for abdominal organs (liver, 0.72 x 10(-3) mm2/sec; spleen, 0.80 x 10(-3) mm2/sec; kidney, 1.38 x 10(-3) mm2/sec; gallbladder, 2.82 x 10(-3) mm2/sec) and for hepatic lesions (hepatocellular carcinoma, 1.02 x 10(-3) mm2/sec; metastasis, 1.16 x 10(-3) mm2/sec; hemangioma, 1.31 x 10(-3) mm2/sec; cysts, 3.03 x 10(-3) mm2/sec). The ADCs of solid organs and solid lesions were significantly higher than their D values, indicating a high contribution of perfusion to the ADCs.
  
  
  CONCLUSIONS
  Perfusion contributes to the ADCs of abdominal organs and hepatic lesions. The D and f values are useful for the characterization of hepatic lesions.
authors: Department of Radiology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
authors: I
authors: I
authors: Yamada
authors: W
authors: W
authors: Aung
authors: Y
authors: Y
authors: Himeno
authors: T
authors: T
authors: Nakagawa
authors: H
authors: H
authors: Shibuya
mesh_terms: D000005:Abdomen / Q000473:pathology*; D000328:Adult; D000368:Aged; D001201:Ascites / Q000175:diagnosis; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis; D003560:Cysts / Q000175:diagnosis; D004058:Diffusion; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D005704:Gallbladder / Q000473:pathology; D006392:Hemangioma, Cavernous / Q000175:diagnosis; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007668:Kidney / Q000473:pathology; D008099:Liver / Q000473:pathology; D008107:Liver Diseases / Q000175:diagnosis*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology; D010179:Pancreas / Q000473:pathology; D013154:Spleen / Q000473:pathology