Hi Colin
There is a guide how to force freesurfer using higher resolution than 1x1x1 mm. It was written by Falk Lüsebrink. If you search in the FS archive with:
Measuring cortical thickness with high resolution data
You find some threads on this topic
Cheers
Jürgen
On [DATE], "Colin Reveley" <[ADDRESS]> wrote:
Hi -
I would really like to use a volume size greater than 256^3.
I know of all the options and reasons.
what I want is a white matter surface than has fairly evenly spaced nodes that are in approximate match to the voxels they enclose.
the reason is to seed, track and target using FSL surface tractography. the brain is a 250um macaque, and it's 320 voxels long unfortunately. the structural and DWI are the same resolution and in register and acpc aligned. such a shame to waste.
the freesurfer surfaces are imported into CARET and cross-registered to F99. but they keep their mesh if I want.
work with another sample showed that node numbers and even coverage over the WM/GM boundary had a signifiant effect on the FSL metrics, with the original FS WM surface and derivatives yielding the best results over other meshes like F99's or anything made with surefit directly from a downsampled version of the data. that data I could fit into 256^3.
I doubt that the nodes and voxels need to match perfectly, just ballpark and fairly even spacing.
if I used a downsampled volume at 500um to make surfaces in freesurfer, maybe I could upsmaple the surfaces afterwards? but then the pial and white would have to be resampled independently and that's probably no good.
If I have to resample the volume or apply a scaling transform the world won't end. In fact it will take less time to do probably. But it would be nice to use a larger size than 256^3 to take advantage of what I've got.
best,
Colin, Sussex
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The information in this e-mail is intended only for the person to whom it is
addressed. If you believe this e-mail was sent to you in error and the e-mail
contains patient information, please contact the Partners Compliance HelpLine at
http://www.partners.org/complianceline . If the e-mail was sent to you in error
but does not contain patient information, please contact the sender and properly
dispose of the e-mail.
----------------------------------------------------------------------------
Jürgen Hänggi, Ph.D.
Division Neuropsychology
Institute of Psychology
University of Zurich
Binzmuehlestrasse 14, PO Box 25
8050 Zurich, Switzerland
0041 44 635 73 97 (phone office)
0041 76 445 86 84 (phone mobile)
0041 44 635 74 09 (fax office)
BIN 4.D.04 (office room number)
j.haenggi[at]psychologie.uzh.ch (email)
http://www.psychologie.uzh.ch/neuropsy/ (website)
http://www.juergenhaenggi.ch (private website)
This e-mail (and any attachment/s) contains confidential and/or privileged
information. If you are not the intended recipient (or have received this
e-mail in error) please notify the sender immediately and destroy this
e-mail. Any unauthorised copying, disclosure or distribution of the
material in this e-mail is strictly forbidden.
----------------------------------------------------------------------------