you can apply it to the raw data. The tensor is just assembled from the regression coefficients (betas) in the standard way, ie, a design matrix is constructed with 7 columns. Each column consists of [gx gy gz gx*gy gx*gz gy*gz 1], and the 1st 6 coefficients for the tensor.

doug

李猛 wrote:

Thank you very much. In fact, I want to insert the bet module before calculating the tensor, eigvals, eigvecs, fa, ra etc in dt_recon. I also know mri_glmfit can create glm-related images. But I can't find the tensor calculation in (mri_glmfit --y $fec --glmdir $OutDir --dti $bvals $bvecs).

On Tue, Jul 7, 2009 at 12:36 AM, Douglas N Greve <greve@nmr.mgh.harvard.edu mailto:greve@nmr.mgh.harvard.edu> wrote:

It just takes the log of the input and constructs a design matrix
from your bvals and bvecs, then fits a glm.

doug

?? wrote:

    Hi, All.
    The related item of "Fitting Tensors" is listed from the dt_recon.

    # Fit tensors
    echo "#@#-------------------------------" | tee -a $LF
    echo "Fitting Tensors" | tee -a $LF
    date | tee -a $LF

    set cmd = (mri_glmfit --y $fec --glmdir $OutDir);
    if($#bvals == 0) then
    set cmd = ($cmd --dti $infodump)
    else
    set cmd = ($cmd --dti $bvals $bvecs)
    endif

    However, I can't find any description about this
    argument(--dti) in mri_glmfit. Did the mri_glmfit call the
    dtifit to fit the tensor from fsl?If not, what is it?

    -- 
    Albert
    Lab of Complex System and Artificial Intelligence,
    Institute of Automation,Chinese Academy of Sciences(CASIA)
    Beijing, 100190,P.R.CHINA


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