Comparison of Single-shot Echo-planar and Line Scan Protocols for Diffusion Tensor Imaging

M. Kubicki, S. E. Maier, C.-F. Westin, H. Mamata, H. Ersner-Hershfield, R. San Jose Estepar, R. Kikinis, F. A. Jolesz, R. W. McCarley, M. E. Shenton
Academic Radiology
Volume 11, Number 2, Pages 224-232
2004

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Abstract

Rationale and Objectives. Both single-shot diffusion-weighted echo-planar imaging (EPI) and line scan diffusion imaging (LSDI) can be used to obtain magnetic resonance diffusion tensor data and to calculate directionally invariant diffusion anisotropy indices, ie, indirect measures of the organization and coherence of white matter fibers in the brain. To date, there has been no comparison of EPI and LSDI. Because EPI is the most commonly used technique for acquiring diffusion tensor data, it is important to understand the limitations and advantages of LSDI relative to EPI.

Materials and Methods. Five healthy volunteers underwent EPI and LSDI diffusion on a 1.5 Tesla magnet (General Electric Medical Systems, Milwaukee, WI). Four-mm thick coronal sections, covering the entire brain, were obtained. In addition, one subject was tested with both sequences over four sessions. For each image voxel, eigenvectors and eigenvalues of the diffusion tensor were calculated, and fractional anisotropy (FA) was derived. Several regions of interest were delineated, and for each, mean FA and estimated mean standard deviation were calculated and compared.

Results. Results showed no significant differences between EPI and LSDI for mean FA for the five subjects. When intersession reproducibility for one subject was evaluated, there was a significant difference between EPI and LSDI in FA for the corpus callosum and the right uncinate fasciculus. Moreover, errors associated with each FA measure were larger for EPI than for LSDI.

Conclusion. Results indicate that both EPI- and LSDI-derived FA measures are sufficiently robust. However, when higher accuracy is needed, LSDI provides smaller error and smaller inter-subject and inter-session variability than EPI.

Key Words. Diffusion; single-shot EPI; LSDI; anisotropy.

Placement of the ROIs. Yellow, corpus callosum; green and red, uncinate fasciculus; pink, superior frontal gyrus; brown and magenta, internal capsule.

Reference

Kubicki M, Maier SE, Westin CF, Mamata H, Ersner-Hershfield H, San Jose Estepar R, Kikinis R, Jolesz FA, McCarley RW, Shenton ME. Comparison of single-shot echo-planar and line scan protocols for diffusion tensor imaging. Academic Radiology 2004;11(2):224-232.

Bibtex entry

@Article{kubickiAcademRad04,
  author         = {M. Kubicki and S. E. Maier and C.-F. Westin and H. Mamata  
                   and  H. Ersner-Hershfield and R. {San Jose Estepar} and R.  
                   Kikinis  and F. A. Jolesz and R. W. McCarley and M. E.      
                   Shenton},                                                   
  title          = {Comparison of Single-shot Echo-planar and Line Scan        
                   Protocols for  Diffusion Tensor Imaging},                   
  journal        = {Academic Radiology},                                       
  year           = 2004,                                                       
  volume         = 11,                                                         
  number         = 2,                                                          
  pages          = {224--232}
}

Grants

NIH P41-RR13218 (NAC), NIH K02-MH01110, NIH R01-MH50747, NIH R01-MH40799, NIH R01-NS39335, NIH R01-RR11747, NIH P41-RR13218 (NAC)

Research areas

DTMRI, Tensor