title: Diffusion tensor magnetic resonance imaging of the normal breast.
abstract: OBJECTIVE
  The objective of this study was to evaluate diffusion anisotropy of the breast parenchyma and assess the range and repeatability of diffusion tensor imaging (DTI) parameters in normal breast tissue.
  
  
  METHODS
  The study was approved by our institutional review board and included 12 healthy females (median age, 36 years). Diffusion tensor imaging was performed at 1.5 T using a diffusion-weighted echo planar imaging sequence. Diffusion tensor imaging parameters including tensor eigenvalues (lambda(1), lambda(2), lambda(3)), fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured for anterior, central and posterior breast regions.
  
  
  RESULTS
  Mean normal breast DTI measures were lambda(1)=2.51 x 10(-3) mm(2)/s, lambda(2)=1.89 x 10(-3) mm(2)/s, lambda(3)=1.39 x 10(-3) mm(2)/s, ADC=1.95+/-0.24 x 10(-3) mm(2)/s and FA=0.29+/-0.05 for b=600 s/mm(2). Significant regional differences were observed for both FA and ADC (P<.05), with higher ADC in the central breast and higher FA in the posterior breast. Comparison of DTI values calculated using b=0, 600 s/mm(2) vs. b=0, 1000 s/mm(2), showed significant differences in ADC (P<.001), but not FA. Repeatability assessment produced within-subject coefficient of variations of 4.5% for ADC and 11.4% for FA measures.
  
  
  CONCLUSIONS
  This study demonstrates anisotropy of water diffusion in normal breast tissue and establishes a normative range of breast FA values. Attention to the influence of breast region and b value on breast DTI measurements may be important for clinical interpretation and standardization of techniques.
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA 98195, USA. scp3@u.washington.edu
authors.forename: Savannah C
authors.initials: SC
authors.lastname: Partridge
authors.forename: Revathi S
authors.initials: RS
authors.lastname: Murthy
authors.forename: Ali
authors.initials: A
authors.lastname: Ziadloo
authors.forename: Steven W
authors.initials: SW
authors.lastname: White
authors.forename: Kimberly H
authors.initials: KH
authors.lastname: Allison
authors.forename: Constance D
authors.initials: CD
authors.lastname: Lehman
mesh_terms: D000328:Adult; D016880:Anisotropy; D001940:Breast / Q000033:anatomy & histology* / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity