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help > RE: Exact calculation of the Framewise Displacement
Oct 11, 2022 10:10 PM | Alfonso Nieto-Castanon - Boston University
RE: Exact calculation of the Framewise Displacement
Dear Marie
That's a good point from the reviewer, you could quote the description of CONN's framewise displacement measure as:
"Framewise displacement is computed at each timepoint by considering a 140x180x115mm bounding box around the brain and estimating the largest displacement among six control points placed at the center of these bounding-box faces."
Nieto-Castanon, A. (2020). FMRI minimal preprocessing pipeline. In Handbook of functional connectivity Magnetic Resonance Imaging methods in CONN (pp. 3–16). Hilbert Press. doi:10.56441/hilbertpress.2207.6599
For more details see also "help conn_convertl12l1covariate" (see FD_CONN definition there), and if you want you could also use that same function to compute other alternative definitions of framewise displacement (e.g. FD_power or FD_jenkinson) on your own data, as the reviewer is correct, there are a lot of similar-but-not-exactly-the-same FD definitions simultaneously being used in the literature, so it is a good idea to be as precise as possible.
Hope this helps
Alfonso
Originally posted by msc_22:
That's a good point from the reviewer, you could quote the description of CONN's framewise displacement measure as:
"Framewise displacement is computed at each timepoint by considering a 140x180x115mm bounding box around the brain and estimating the largest displacement among six control points placed at the center of these bounding-box faces."
Nieto-Castanon, A. (2020). FMRI minimal preprocessing pipeline. In Handbook of functional connectivity Magnetic Resonance Imaging methods in CONN (pp. 3–16). Hilbert Press. doi:10.56441/hilbertpress.2207.6599
For more details see also "help conn_convertl12l1covariate" (see FD_CONN definition there), and if you want you could also use that same function to compute other alternative definitions of framewise displacement (e.g. FD_power or FD_jenkinson) on your own data, as the reviewer is correct, there are a lot of similar-but-not-exactly-the-same FD definitions simultaneously being used in the literature, so it is a good idea to be as precise as possible.
Hope this helps
Alfonso
Originally posted by msc_22:
Dear Alfonso,
A reviewer is asking us for the exact calculation of the Framewise Displacement as several FD metrics are available in the literature. Could you please let us know how Framewise Displacement is calculated in CONN and whether it follows the traditional definition by Power?
Many thanks
A reviewer is asking us for the exact calculation of the Framewise Displacement as several FD metrics are available in the literature. Could you please let us know how Framewise Displacement is calculated in CONN and whether it follows the traditional definition by Power?
Many thanks
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| Title | Author | Date |
|---|---|---|
| msc_22 | Oct 7, 2022 | |
| Alfonso Nieto-Castanon | Oct 11, 2022 | |
| msc_22 | Oct 12, 2022 | |