Alexander,
This link has some info for Siemens DTI:
http://www.na-mic.org/Wiki/index.php/NAMIC_Wiki:DTI:DICOM_for_DWI_and_DTI
If you use the suggested code snippet:
P= spm_get(Inf,'*','Selct some files')
hdr=spm_dicom_headers(P)
hdr{1}.CSAImageHeaderInfo(22).item(1).val
hdr{1}.CSAImageHeaderInfo(22).item(2).val
hdr{1}.CSAImageHeaderInfo(22).item(3).val
you may want to include a check like this to skip files without a gradient:
if ~isempty(hdr{i}.CSAImageHeaderInfo(22).item)
or simply don't select the non-gradient files for the reported values since
these header fields may be empty.
Kathy Pearson
UAB Psychology
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On
Behalf Of Alexander Lebedev
Sent: Tuesday, March 24, 2009 4:53 PM
To: [log in to unmask]
Subject: [SPM] B-values and gradient directions ("Diffusion II" toolbox)
Dear SPMers.
Excuse me for a stupid question. I have a problem with preprocessing in
"diffusion II" toolbox
Could you tell me how exactly it is needed to enter b-values and
gradients?
I have 84 dicom files getting from scaner (Siemens Magnetom Symphony 1.5
T) in 13 directions (b0 + 12 dwi). After the convertation process they
transform into 168(84 img + 84headers) files. What must I enter at the
"B values" and "Gradient directions" lines?
Is it ok:
- B values:
0 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000
- Gradient directions:
0.000, 0.000, 0.000
1.000, 0.000, 0.500
0.000, 0.500, 1.000
0.500, 1.000, 0.000
1.000, 0.500, 0.000
0.000, 1.000, 0.500
0.500, 0.000, 1.000
1.000, 0.000, -0.500
0.000, -0.500, 1.000
-0.500, 1.000, 0.000
1.000, -0.500, 0.000
0.000, 1.000, -0.500
-0.500, 0.000, 1.000
Thank you beforehand...
--
Alexander Lebedev.
