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questions > Question about bvec (diffusion MR) converted using dcm2niix
Sep 19, 2019 04:09 PM | eegee
Question about bvec (diffusion MR) converted using dcm2niix
Dear Experts,
Hi, I have been using dcm2niix to convert DMRI files to BIDS format, and noticed a significant change in bvec file.
Using Siemens scanner, we have used customized diffusion vector file that looks like
CoordinateSystem = prs
vector[0] =( 0.0804, -0.3699, 0.9256) ...
Thus, I expected that the bvec output from dcm2niix will be somehow similar to this value (a little difference perhaps due to oblique acquisition).
But the result is something like
(-0.3699, 0.0804, 0.9256)
... showing that the x and y coordinates are switched.
Here I would like to ask you three things:
1. So what is the correct (meaning that it reflects what the scanner actually did) bvec file to use?
2. Do I have to switch x and y manually after obtaining bvec from dcm2niix, or should I change diffusion vector coordinate system to xyz, instead of prs?
3. Why is this happening?
Thank you very much for your help in advance!
Hi, I have been using dcm2niix to convert DMRI files to BIDS format, and noticed a significant change in bvec file.
Using Siemens scanner, we have used customized diffusion vector file that looks like
CoordinateSystem = prs
vector[0] =( 0.0804, -0.3699, 0.9256) ...
Thus, I expected that the bvec output from dcm2niix will be somehow similar to this value (a little difference perhaps due to oblique acquisition).
But the result is something like
(-0.3699, 0.0804, 0.9256)
... showing that the x and y coordinates are switched.
Here I would like to ask you three things:
1. So what is the correct (meaning that it reflects what the scanner actually did) bvec file to use?
2. Do I have to switch x and y manually after obtaining bvec from dcm2niix, or should I change diffusion vector coordinate system to xyz, instead of prs?
3. Why is this happening?
Thank you very much for your help in advance!
Threaded View
Title | Author | Date |
---|---|---|
eegee | Sep 19, 2019 | |
Chris Rorden | Sep 19, 2019 | |
eegee | Sep 19, 2019 | |
eegee | Sep 20, 2019 | |
Chris Rorden | Sep 20, 2019 | |
Chris Rorden | Sep 19, 2019 | |
eegee | Sep 19, 2019 | |