open-discussion
open-discussion > RE: Motion correction
Oct 19, 2016 03:10 PM | James Hartzell
RE: Motion correction
Hi
I have a related question.
With the rot_bvecs script one can adjust the bvec gradient orientations to the applied motion correction and eddy current correction in the eddy_correct script.
Is there a way to do the same with DTIPrep--i.e., adjust the gradient vectors according to the applied motion correction?
Originally posted by Martin Styner:
I have a related question.
With the rot_bvecs script one can adjust the bvec gradient orientations to the applied motion correction and eddy current correction in the eddy_correct script.
Is there a way to do the same with DTIPrep--i.e., adjust the gradient vectors according to the applied motion correction?
Originally posted by Martin Styner:
I assume you meant FSL
(using fsl_motion_outliers)?
Not sure how the RMS motion is computed, and this could be an artifact of the particular program you are using to compute the motion. If there were such a thing as a perfect way to measure motion, we would simply use that measure as a goal to optimize. But any measure introduces a bias to its assumptions.
But it is certainly not impossible for DTIPrep (or any motion correction, such as in FSL) to make things worse. Especially if there is no motion present, a registration process (to correct the potential motion) may correct for a larger motion than actually present (due to the high noise, low SNR).
Martin
Not sure how the RMS motion is computed, and this could be an artifact of the particular program you are using to compute the motion. If there were such a thing as a perfect way to measure motion, we would simply use that measure as a goal to optimize. But any measure introduces a bias to its assumptions.
But it is certainly not impossible for DTIPrep (or any motion correction, such as in FSL) to make things worse. Especially if there is no motion present, a registration process (to correct the potential motion) may correct for a larger motion than actually present (due to the high noise, low SNR).
Martin
Threaded View
| Title | Author | Date |
|---|---|---|
| Tanmay Nath | Oct 16, 2016 | |
| Martin Styner | Oct 17, 2016 | |
| James Hartzell | Oct 19, 2016 | |
| Martin Styner | Oct 19, 2016 | |
| James Hartzell | Oct 19, 2016 | |