title: Evaluation of liver hemangiomas using three different b values on diffusion MR.
abstract: OBJECTIVE
  To determine which diffusion-weighted MR technique (i.e., b-100, b-600, b-1000 s/mm(2)) is most useful in depicting liver hemangiomas. We also aimed to assess the effect of lesion size on apparent diffusion coefficient (ADC) values.
  
  
  METHODS
  Diffusion-weighed MR (DWMR) was performed for 61 hemangiomas in 32 patients. DWMR images were obtained before contrast administration using three different b values of 100, 600, and 1000 s/mm(2). ADCs were measured for each lesions and compared with normal liver parenchymal ADCs on different b values. Hemangiomas were subdivided according to lesion size (less than 3 cm and 3 cm or greater). Data were analyzed using SPSS software by analysis of variances (ANOVA) and post hoc values were tested using HSD Tukey test.
  
  
  RESULTS
  There was no significant relation between lesion size and ADC values on different b values. Lower ADC values were obtained for higher b values in normal liver tissue and hemangiomas. Although there is significant difference between normal liver tissue and hemangiomas; this is more apparent on b-1000 images (p=0.022 on b-100, p=0.003 on b-600, and p=0.000 on b-1000 images). Variance analysis revealed hemangiomas had higher ADC values than normal liver tissue on b-1000 images.
  
  
  CONCLUSIONS
  Mean values for ADCs of hemangiomas were lower than ADCs of the normal liver except for b-1000 value. Higher b values are useful for the differentiation between normal liver tissue and hemangiomas. Lesion size does not affect ADC measurement on different b values.
authors.affiliation: Department of Radiology, Faculty of Medicine, Firat University, 23119 Elazig, Turkey. bozgeyik4@hotmail.com
authors.forename: Zulkif
authors.initials: Z
authors.lastname: Bozgeyik
authors.forename: Ercan
authors.initials: E
authors.lastname: Kocakoc
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Gul
authors.forename: A Ferda
authors.initials: AF
authors.lastname: Dagli
mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006391:Hemangioma / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity