= Distortion correction using interlaced q-space sampling =

This page provides a precompiled Matlab implementation ("p-code:) of a distortion correction method for diffusion MRI using the interlaced q-space sampling technique. This method uses interlaced phase-encoding directions (IPED) while sampling the q-space, which enables accurate distortion correction without increasing the acquisition time. Please see following references for more details of the method:

 1. C. Bhushan, A. A. Joshi, R. M. Leahy and J. P. Haldar (2014), '''Improved B0-distortion correction in diffusion MRI using interlaced q-space sampling and constrained reconstruction'''. Magnetic Resonance in Medicine, 72: 1218-1232. doi: [[http://dx.doi.org/10.1002/mrm.25026|10.1002/mrm.25026]]

 1. C. Bhushan, A. A. Joshi, R. M. Leahy and J. P. Haldar (2013), '''Accelerating data acquisition for reversed-gradient distortion correction in diffusion MRI: A constrained reconstruction approach'''. 21st Scientific Meeting of International Society for Magnetic Resonance in Medicine (ISMRM), Salt Lake City, p. 55. [[http://neuroimage.usc.edu/~chitresh/papers/ismrm_2013_EPI_distortion_correction.pdf|Abstract PDF]], [[http://cds.ismrm.org/protected/13MPresentations/0055/|ISMRM presentation video]]

== Usage ==

The method is implemented in form of a Matlab function, named {{{IPEDcorrect}}}, and requires [[http://www.mathworks.com/products/image/|Image processing toolbox]]. It only supports use of [[http://nifti.nimh.nih.gov/nifti-1|NIfTI-1 data format]] for image and plain text-files for specifying other parameters. Either of following syntax is supported:{{{
IPEDcorrect(IPED_config_filename, fieldmap_filename, echo_spacing, output_base)
IPEDcorrect(IPED_config_filename, fieldmap_filename, echo_spacing, output_base, user_opts)
}}}
where, 
 * IPED_config_filename
 * fieldmap_filename
 * echo_spacing
 * output_base
 * user_opts

=== IPED_config_filename ===



[[attachment:BST-view.png| BrainSuite view]]

[[attachment:IPED_ped_eg.png|{{attachment:IPED_ped_eg_small.png||width=350}}]]

=== user_opts ===

== Downloads ==

This code is licensed under the [[http://creativecommons.org/licenses/by-nc-sa/4.0/|CC Attribution-Noncommercial-Share Alike 4.0 License]]. Please cite [1] and [2] if you use this code or its derivatives in your own work.

In no event shall the University of Southern California, the Authors, or the Distributors be liable to any party for direct, indirect, special, incidental, or consequential damages, including lost profits, arising out of the use of this software, its documentation, or any derivatives thereof, even if the authors have been advised of the possibility of such damage. The University of Southern California, the Authors, and the Distributors specifically disclaim any warranties, including, but not limited to, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement. This software is provided on an "as is" basis, and the authors and distributors have no obligation to provide maintenance, support, updates, enhancements, or modifications. This software is for research purposes only and has not been approved for clinical use.

 * Download {{{IPEDcorrect.zip}}} (Last Modified: Apr 12, 2015)

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