Re: [Freesurfer] DTI - Tracula question

Hi Anastasia:

Thank you so much. Yes that is very helpful.

best,

Alan

On Fri, Feb 5, 2016 at 3:03 PM, Anastasia Yendiki < ayendiki@nmr.mgh.harvard.edu> wrote:

Hi Alan - Yes, you can give a single file for all data sets if they're all acquired with the same gradient table and slice prescription. As a test, you can extract the gradient tables from a couple of your data set's dicom headers and see how different they are. If there are only very small differences, using a single table for all will not make a difference.

Hope this helps,

a.y

On Fri, 5 Feb 2016, Alan Francis wrote:

Thanks Anastasia - that was very helpful. I have another question : I am

...

working on a DTI dataset of around 70 subjects. This dataset has ostensibly only 1 set of BVECS/BVALS. Can this set be 'generically' used for all the images, given that they have been acquired on the same scanner?

thanks,

Alan

On Wed, Feb 3, 2016 at 4:17 PM, Anastasia Yendiki < ayendiki@nmr.mgh.harvard.edu> wrote:

  Hi Alan - A nifti file with the gradient tables and b-values

embedded? All freesurfer programs can handle nifti volumes, compressed (.nii.gz) or not (.nii). You can pass those volumes to TRACULA, and pass the gradient table and b-value table as separate files.

  Run "mri_convert --help" to see all image file formats that we can

handle.

  Hope this helps,
  a.y

  On Wed, 3 Feb 2016, Alan Francis wrote:

        Hi Anastasia:

        I am working on a set of DTI data that were obtained at the

Martinos center. The data is in a single nii.gz file. The BVECS and BVALS files are also embedded in this. Could you please advice me how do I code this in the DMRIRC file?

        Should I convert the nii.gz file into Analyze to get at the

BVECS/ BVALS?

        thank you so much,

        best regards,

        Alan

        --

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        Alan N. Francis PhD
        NIDA T32  Fellow in Computational Neuroscience
        Brain Imaging Center
        McLean Hospital
        Harvard Medical School
        115 Mill Street, Belmont, MA 02478
        alanf@bwh.harvard.edu
        afrancis@mclean.harvard.edu

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Alan N. Francis PhD NIDA T32 Fellow in Computational Neuroscience Brain Imaging Center McLean Hospital Harvard Medical School 115 Mill Street, Belmont, MA 02478 alanf@bwh.harvard.edu afrancis@mclean.harvard.edu

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