I have some data for which I only have the reconstructed tensor images (nifti). As per my assumption nifti holds the tensor in lower triangular order( xx, xy, yy, xz,yz, zz). But when I use this tensor image in Diffusion toolkit for tractography, it gives me wrong tracks. So I want to know in what order are the tensor elements arranged?

For information, below is the hdr for my nifti:

Please help me,

Madhura

sizeof_hdr     348
data_type      FLOAT32
dim0           5
dim1           128
dim2           128
dim3           90
dim4           1
dim5           6
dim6           1
dim7           1
vox_units      mm
time_units     Unknown
datatype       16
nbyper         4
bitpix         32
pixdim0        0.0000000000
pixdim1        2.0000000000
pixdim2        2.0000000000
pixdim3        2.0000000000
pixdim4        1.0000000000
pixdim5        1.0000000000
pixdim6        0.0000000000
pixdim7        0.0000000000
vox_offset     352
cal_max        0.0000
cal_min        0.0000
scl_slope      1.000000
scl_inter      0.000000
phase_dim      0
freq_dim       0
slice_dim      0
slice_name     Unknown
slice_code     0
slice_start    0
slice_end      0
slice_duration 0.000000
time_offset    0.000000
intent         Symmetric matrix
intent_code    1005
intent_name    
intent_p1      0.000000
intent_p2      0.000000
intent_p3      0.000000
qform_name     Aligned Anat
qform_code     2
qto_xyz:1      -2.000000  -0.000000  -0.000000  -0.000000
qto_xyz:2      0.000000  2.000000  -0.000000  -0.000000
qto_xyz:3      -0.000000  0.000000  2.000000  0.000000
qto_xyz:4      0.000000  0.000000  0.000000  1.000000
qform_xorient  Right-to-Left
qform_yorient  Posterior-to-Anterior
qform_zorient  Inferior-to-Superior
sform_name     Scanner Anat
sform_code     1
sto_xyz:1      -2.000000  -0.000000  0.000000  -0.000000
sto_xyz:2      -0.000000  2.000000  -0.000000  -0.000000
sto_xyz:3      0.000000  0.000000  2.000000  0.000000
sto_xyz:4      0.000000  0.000000  0.000000  1.000000
sform_xorient  Right-to-Left
sform_yorient  Posterior-to-Anterior
sform_zorient  Inferior-to-Superior
file_type      NIFTI-1+
file_code      1
descrip        

Ruopeng said:

How "wrong" do the tracks look? More info would be helpful…

Ruopeng

First of all the tracks r only constrcuted in middle part of the brain (This might be cos of masking). The pic can tell u more.