title: Dynamic diffusion-tensor measurements in muscle tissue using the single-line multiple-echo diffusion-tensor acquisition technique at 3T.
abstract: When diffusion biomarkers display transient changes, i.e. in muscle following exercise, traditional diffusion-tensor imaging (DTI) methods lack the temporal resolution to resolve the dynamics. This article presents an MRI method for dynamic diffusion-tensor acquisitions on a clinical 3T scanner. This method, the Single-Line Multiple-Echo Diffusion-Tensor Acquisition Technique (SL-MEDITATE), achieves a high temporal resolution (4 s) by rapid diffusion encoding through the acquisition of multiple echoes with unique diffusion sensitization and limiting the readout to a single line volume. The method is demonstrated in a rotating anisotropic phantom, a flow phantom with adjustable flow speed and in vivo skeletal calf muscle of healthy volunteers following a plantar flexion exercise. The rotating and flow-varying phantom experiments show that SL-MEDITATE correctly identifies the rotation of the first diffusion eigenvector and the changes in diffusion-tensor parameter magnitudes, respectively. Immediately following exercise, the in vivo mean diffusivity (MD) time courses show, before the well-known increase, an initial decrease that is not typically observed in traditional DTI. In conclusion, SL-MEDITATE can be used to capture transient changes in tissue anisotropy in a single line. Future progress might allow for dynamic DTI when combined with appropriate k-space trajectories and compressed sensing reconstruction.
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY, USA.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Baete
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY, USA.|Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY, USA.
authors.forename: Gene Y
authors.initials: GY
authors.lastname: Cho
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY, USA.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Sigmund
mesh_terms: D000328:Adult; D000465:Algorithms; D016880:Anisotropy; D056324:Diffusion Tensor Imaging / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000098:blood supply / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: DTI; MEDITATE; dynamic diffusion; exercise; fast acquisition; multiple-modulation multiple echo; skeletal muscle