Post edited 7:25 pm – March 9, 2010 by dp317

I noticed on your the "CommandLine Tools" page of DTK (http://trackvis.org/dtk/?subsect=script)

that you can reconstruct DSI using only some of the data:

"Example:

  assume the raw dsi data has 514 diffusion volumes and 4 lowb(b0) volumes.

  1. normal reconstruction -

        odf_recon rawdsi 515 181 recon_out

  2. to reconstruct using only part of the raw images -

        odf_recon rawdsi 251 181 recon_out -b0 4

     in this case, -b0 must be specified as the program will
     use number of raw image volumes (518)-251+1 as number of b0s,
     which is obviously wrong"

So say I have 258 scans (with b-values ranging from 0 to 5000) but I'd like to 

only use the first part of that with b-values ranging from 0 to 1000. I think 

I should then use diff_unpack -> odf_recon -> odf_tracker

Am I right? When I try to do that, I get the following error during odf_recon 

(for example using only the first 100 images, dsi_unpacked is the .nii result 

of diff_unpack):

odf_recon dsi_unpacked 100 181 recon_out100 -b0 1 -mat DSI_matrix_258x181.dat
Volume dimension: 128 128 60
Voxel size: 1.797 1.797 2.000
Reading recon matrix...done
Matrix file being used: DSI_matrix_258x181.dat
Can not find matrix file for tensor reconDSI_matrix_100x10.dat
Tensor recon ignored.
Reconstructing data... 100%
Writing b0 map...Done. 
Writing dwi map...Done.
Reconstruction completed successfully.
Time taken: 00:01:42

Why is odf_recon looking for a tensor matrix of 100x10? 

If it is ignoring the tensor recon, are the result still usable?

When I give the results to odf_tracker, I do get a readable .trk file without any errors.

Thanks very much for your help!