title: Mapping the Orientation of White Matter Fiber Bundles: A Comparative Study of Diffusion Tensor Imaging, Diffusional Kurtosis Imaging, and Diffusion Spectrum Imaging.
abstract: White matter fiber tractography relies on fiber bundle orientation estimates from diffusion MR imaging. However, clinically feasible techniques such as DTI and diffusional kurtosis imaging use assumptions, which may introduce error into in vivo orientation estimates. In this study, fiber bundle orientations from DTI and diffusional kurtosis imaging are compared with diffusion spectrum imaging as a criterion standard to assess the performance of each technique.
  
  
  
  For each subject, full DTI, diffusional kurtosis imaging, and diffusion spectrum imaging datasets were acquired during 2 independent sessions, and fiber bundle orientations were estimated by using the specific theoretic assumptions of each technique. Angular variability and angular error measures were assessed by comparing the orientation estimates. Tractography generated with each of the 3 reconstructions was also examined and contrasted.
  
  
  
  Orientation estimates from all 3 techniques had comparable angular reproducibility, but diffusional kurtosis imaging decreased angular error throughout the white matter compared with DTI. Diffusion spectrum imaging and diffusional kurtosis imaging enabled the detection of crossing-fiber bundles, which had pronounced effects on tractography relative to DTI. Diffusion spectrum imaging had the highest sensitivity for detecting crossing fibers; however, the diffusion spectrum imaging and diffusional kurtosis imaging tracts were qualitatively similar.
  
  
  
  Fiber bundle orientation estimates from diffusional kurtosis imaging have less systematic error than those from DTI, which can noticeably affect tractography. Moreover, tractography obtained with diffusional kurtosis imaging is qualitatively comparable with that of diffusion spectrum imaging. Because diffusional kurtosis imaging has a shorter typical scan time than diffusion spectrum imaging, diffusional kurtosis imaging is potentially more suitable for a variety of clinical and research applications.
authors.affiliation: From the Center for Biomedical Imaging (G.R.G., C.-Y.L., J.A.H., J.H.J.) Department of Neurosciences (G.R.G., J.A.H.) Department of Radiology and Radiological Science (G.R.G., C.-Y.L., J.A.H., J.H.J.), Medical University of South Carolina, Charleston, South Carolina.
authors.forename: G R
authors.identifier: 0000-0002-1322-4519
authors.initials: GR
authors.lastname: Glenn
authors.affiliation: Institute of Biomedical Engineering and Nanomedicine (L.-W.K.), National Health Research Institutes, Miaoli County, Taiwan jense@musc.edu lwkuo@nhri.org.tw.
authors.forename: L-W
authors.identifier: 0000-0002-0306-7329
authors.initials: LW
authors.lastname: Kuo
authors.affiliation: Graduate Institute of Medical Mechatronics (Y.-P.C.), Chang Gung University, Taoyuan, Taiwan.
authors.forename: Y-P
authors.identifier: 0000-0002-1681-5410
authors.initials: YP
authors.lastname: Chao
authors.affiliation: From the Center for Biomedical Imaging (G.R.G., C.-Y.L., J.A.H., J.H.J.) Department of Radiology and Radiological Science (G.R.G., C.-Y.L., J.A.H., J.H.J.), Medical University of South Carolina, Charleston, South Carolina.
authors.forename: C-Y
authors.identifier: 0000-0001-5288-3309
authors.initials: CY
authors.lastname: Lee
authors.affiliation: From the Center for Biomedical Imaging (G.R.G., C.-Y.L., J.A.H., J.H.J.) Department of Neurosciences (G.R.G., J.A.H.) Department of Radiology and Radiological Science (G.R.G., C.-Y.L., J.A.H., J.H.J.), Medical University of South Carolina, Charleston, South Carolina.
authors.forename: J A
authors.identifier: 0000-0002-7755-1818
authors.initials: JA
authors.lastname: Helpern
authors.affiliation: From the Center for Biomedical Imaging (G.R.G., C.-Y.L., J.A.H., J.H.J.) Department of Radiology and Radiological Science (G.R.G., C.-Y.L., J.A.H., J.H.J.), Medical University of South Carolina, Charleston, South Carolina jense@musc.edu lwkuo@nhri.org.tw.
authors.forename: J H
authors.identifier: 0000-0003-3219-4287
authors.initials: JH
authors.lastname: Jensen
mesh_terms: D016880:Anisotropy; D001931:Brain Mapping / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009412:Nerve Fibers; D015203:Reproducibility of Results; D066127:White Matter / Q000000981:diagnostic imaging*