title: Improved diffusion tensor imaging of the optic nerve using multishot two-dimensional navigated acquisitions.
abstract: OBJECTIVE
  A diffusion-weighted multishot echo-planar imaging approach combined with SENSE and a two-dimensional (2D) navigated motion correction was investigated as an alternative to conventional single-shot counterpart to obtain optic nerve images at higher spatial resolution with reduced artifacts.
  
  
  METHODS
  Fifteen healthy subjects were enrolled in the study. Six of these subjects underwent a repeated acquisition at least 2 weeks after the initial scan session to address reproducibility. Both single-shot and multishot diffusion tensor imaging studies of the human optic nerve were performed with matched scan time. Effect of subject motions were corrected using 2D phase navigator during multishot image reconstruction. Tensor-derived indices from proposed multishot were compared against conventional single-shot approach. Image resolution difference, right-left optic nerve asymmetry, and test-retest reproducibility were also assessed.
  
  
  RESULTS
  In vivo results of acquired multishot images and quantitative maps of diffusion properties of the optic nerve showed significantly reduced image artifacts (e.g., distortions and blurring), and the derived diffusion indices were comparable to those from other studies. Single-shot scans presented larger variability between right and left optic nerves than multishot scans. Multishot scans also presented smaller variations across scans at different time points when compared with single-shot counterparts.
  
  
  CONCLUSIONS
  The multishot technique has considerable potential for providing improved information on optic nerve pathology and may also be translated to higher fields.
authors.affiliation: Philips Healthcare Korea, Seoul, Republic of Korea.|Division of Magnetic Resonance Research, Korea Basic Science Institute, Chungbook, Republic of Korea.
authors.forename: Ha-Kyu
authors.initials: HK
authors.lastname: Jeong
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.|Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Blake E
authors.initials: BE
authors.lastname: Dewey
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.|Department of Psychology and Human Development, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Jane A T
authors.initials: JA
authors.lastname: Hirtle
authors.affiliation: Department of Neurology, Vanderbilt University, Nashville, Tennessee, USA.|Department of Ophthalmology, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Lavin
authors.affiliation: Department of Neurology, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Subramaniam
authors.initials: S
authors.lastname: Sriram
authors.affiliation: Department of Neurology, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Siddharama
authors.initials: S
authors.lastname: Pawate
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.|Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.|Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.|Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Gore
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.|Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.|Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.|Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Adam W
authors.initials: AW
authors.lastname: Anderson
authors.affiliation: Department of Biostatistics, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Hakmook
authors.initials: H
authors.lastname: Kang
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.|Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.|Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.|Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Seth A
authors.initials: SA
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D009900:Optic Nerve / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D055815:Young Adult
keywords: 2D navigator; DTI; multishot; optic nerve