Hello all,
I am in the middle of processing DTI data from a 3T Philips magnet and
have run into a problem creating my bvecs file. The gradient table below
was taken directly from the magnet.
1,0,0
0,1,0
0,0,1
-0.1789,-0.1113,-0.9776
-0.0635,0.3767,-0.9242
0.7108,0.0516,-0.7015
0.6191,-0.4385,-0.6515
0.2424,0.7843,-0.571
-0.2589,-0.618,-0.7423
-0.8169,0.1697,-0.5513
-0.8438,0.5261,-0.106
-0.2626,0.9548,-0.1389
0.0001,0.9689,0.2476
0.7453,0.6663,0.0242
0.9726,0.2317,0.0209
0.,0.,0.
I have read on this website
(http://www.nottingham.ac.uk/radiology/paul/software/dti_processing.html)
that you need to "negate the x and z components" before producing the
bvecs file. I'm assuming this is because FSL operates in a different
coordinate system than the Philips scanner.
Could anyone give me information on whether or not I need to negate some
part of this gradient? Are there any other alterations I need to make
before creating my bvecs file?
Thanks so much for any info you can give me
Christi
