title: Stimulated echo diffusion tensor imaging (STEAM-DTI) with varying diffusion times as a probe of breast tissue.
abstract: To explore the application of diffusion tensor imaging (DTI) for breast tissue and breast pathologies using a stimulated-echo acquisition mode (STEAM) with variable diffusion times.
  
  
  
  In this Health Insurance Portability and Accountability Act-compliant study, approved by the local institutional review board, eight patients and six healthy volunteers underwent an MRI examination at 3 Tesla including STEAM-DTI with several diffusion times ranging from 68.5 to 902.5 ms. A DTI model was fitted to the data for each diffusion time, and parametric maps of mean diffusivity, fractional anisotropy, axial diffusivity, and radial diffusivity were computed for healthy fibroglandular tissue (FGT) and lesions. The median value of radial diffusivity for FGT was fitted to a linear decay to obtain an estimation of the surface-to-volume ratio, from which the radial diameter was calculated.
  
  
  
  For healthy FGT, radial diffusivity presented a linear decay with the square root of the diffusion time resulting in a range of estimated radial diameters from 202 to 496 µm, while axial diffusivity presented a nearly time-independent diffusion. Residual fat signal was reduced at longer diffusion times due to the shorter T1 of fat. Residual fat signal to the overall signal in the healthy volunteers' FGT was found to range from 2.39% to 2.55% (shortest mixing time), and from 0.40% to 0.51% (longest mixing time) for the b500 images.
  
  
  
  The use of variable diffusion times may provide an in vivo noninvasive tool to probe diffusion lengths in breast tissue and breast pathology, and might aid by improving fat suppression at longer diffusion times.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:84-93.
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.|Department of Radiology, University of California San Diego (UCSD), La Jolla, California, USA.
authors.forename: Jose R
authors.initials: JR
authors.lastname: Teruel
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Gene Y
authors.initials: GY
authors.lastname: Cho
authors.affiliation: Cancer Institute, New York University School of Medicine, New York, New York, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: Moccaldi Rt
authors.affiliation: Department of Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Pål E
authors.initials: PE
authors.lastname: Goa
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Tone F
authors.initials: TF
authors.lastname: Bathen
authors.affiliation: Siemens Healthcare, Erlangen, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Feiweier
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Sungheon G
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Moy
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Sigmund
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D004058:Diffusion; D056324:Diffusion Tensor Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: breast tissue; diffusion tensor imaging; diffusion time; diffusion-weighted MRI; stimulated echo