Hi Ken,
you should always look at the output from the …long.base directories, those are
the final outputs. Looks to me that you are looking at the cross sectional
produced surfaces from the first stage. Those will be
- in different spaces (as the heads are in different positions in the
What is your command line for visualization? Can you also show the base
image as an underlay?
On 9/24/2020 6:54 PM, KennethSPrice wrote:
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Hello,
I am running a longitudinal study and am examining the pial surface
for my 2 timepoints. The surfaces are
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Hello,
I am running a longitudinal study and am examining the pial surface for my 2
timepoints. The surfaces are slightly offset. Will this effect my statistical
analysis for volume and thickness? I have attached the pial surface for each
time point
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Hello Freesurfers!
I am running a recon-all -long study and one of my subjects is giving me
trouble. The brain segmentation volume for tp2 is greater than tp1. The scans
were taken from the same machine with the same parameters, but the dimensions
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The data will be resampled by FreeSurfer, so as far as I know it should not
make a difference as far as FreeSurfer is concerned.
But if you expect the two subjects to have the same dimensions, and that is not
true, I would still check why that is
Hi Gregory,
If looking at longitudinal changes, I would use uncorrected ROI
volumes. You could consider including ICV as a covariate (for offset
and slope interaction, to test if ICV has an effect on your slopes).
Best, Martin
On 05/19/2017 04:44 PM, Gregory Book wrote:
In writing a paper
In writing a paper of longitudinal changes in a large heterogeneous
population with no group comparisons, what would be considered "more
important" to include: absolute ROI volumes, or volumes corrected for ICV?
Using ICV corrected volumes makes sense when comparing groups, but when
just
Hi:
I want to do a longitudinal study between two time points of a patient... I
want to compare the volume of the hypocampii, white matter, etc... I did
the computation of both time points, I created the base image, and the
long ones... How can I analyze the aseg.stats files in each long folder
Hi Gonzalo,
yes, exactly, you only look at the *.long.* folders. Take a look at this
page:
http://surfer.nmr.mgh.harvard.edu/fswiki/LongitudinalStatistics
specifically if you have 2 time points for all subjects, you can use the
tools for analyzing slopes:
Hi:
For example: if I want to compare the volume of left hyppocampus in two
time points, could I compare the volume in aseg.stats file of both long
folders?...
Sincerely,
Gonzalo Rojas Costa
Gonzalo Rojas Costa
Advanced Medical Image Processing Laboratory
In terms of just giving it a name, it should not matter since all of the
time points are treated equally in the longitudinal stream. When you go
to analyze it, the order will make a difference (and I assume you'll use
phase).
doug
On 05/07/2012 11:59 PM, lordowen wrote:
Hi all:
We performed a
Hi,
I'd recommend to use time for the order when processing. The order of time
points is not relevant in the longitudinal stream but this way the design is
more balanced.
Best Martin
On May 7, 2012, at 23:59, lordowen lordowe...@gmail.com wrote:
Hi all:
We performed a thickness change
Hi all:
We performed a thickness change study which related to the menstrual
cycle. We scanned subjects during different menstrual phases in a
counterbalance manner. Thus when we conduct a longitudinal analysis,
we need to set time point according to the actual scanning order
(i.e., 1st scan as
Hi, there,
I am going to run the FreeSurfer Longitudinal Stream (FS 4.5) on data from
different timepoints.
Do we need cross-sectionally process all time points with the default workflow,
or just need run the first step
of the default workflow.
Thanks a lot!
Guang
Hi Linda,
we haven't found any problems in that age range. Down to 3 years old is
probably fine, although if you were scanning that young there might be
some things we would advise. 1l years old is no problem though.
cheers,
Bruce
On Tue, 13 Nov 2007, Linda.E Campbell wrote:
Hi,
I am
Hi,
I am about to start processing some longitudinal data and am looking for
appropriate software. I know the Freesurfer allows for longitudinal
designs but how appropriate is it to use for developing brains, ie in my
sample the subjects are adolescents between 14-20 and they were last
scanned
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