Sorry, I think I gave you some incorrect info. Try this instead:

tkregister2 --targ bold/004/fmc.bhdr --mov bold/009/fmc.bhdr --identity
  --reg /tmp/junk.reg

I just added the --identity to tkregister2. I tried to look at your
data to verify that this was the problem, but it is sooooooooooo

Let me know how it goes.

doug


On Tue, 7 Mar 2006 [EMAIL PROTECTED] wrote:

Hi Doug,

I tried the technique you suggested for re-sampling functional volumes
from different sessions but from the same subject (and scanner) into the
same space, using mc-sess.

To clarify, here we have a situation where the same brain is scanned in
the same scanner on more than one occasion (in this particular example,
the subjects were taken out of the scanner half way through the lengthy
functional recordings for 20 minutes to rest). Obviously the head position
and rotation are almost always quite different in session 1 than session
2. It would make building contrasts and combining results across sessions
(but within subjects) much more straigthforward if the functional volumes
from the two "sessions" could be re-sampled into the same space.

I put all my runs (2 sessions, 3 runs each = total of 6 runs) from the
same subject and scanner in one bold directory, ran mc-sess, and got
confusing results.

When I check the alignment with tkregister2, the result looks very bad -
the volumes from different sessions are clearly not in the same space (1-3
cm difference).

However if I ignore the fact that the runs do not appear to be aligned,
and run spmregister-sess just once for all runs (hence there is only one
register.dat file) and then check the registration with tkregister-sess,
runs from both sessions seem to be similarly and well aligned with the
hires anatomicals. Obviously the mis-alignment from mc-sess should be
inherited to all following steps, so I must be doing something wrong. I
wonder where the mistake is? Am I misusing the tkregister 2 command (see
below)? Or is this a bug?

*** Here are the specifics: ***

Session 1 = runs 004, 005, 006
Session 2 = runs 009, 010, 011

on machine ai

source /usr/local/freesurfer/nmr-dev-env
setenv SUBJECTS_DIR /space/cognito/5/users/raij/subjects_mri
setenv SUBJECT avml19

cd
/space/cognito/21/users/raij/avml_fmri_mctogether/avml19_session_BRISI13_ISI1TR_BERT

# MOTION CORRECT
mc-sess -sf sessid -df sesspar

# SPATIAL SMOOTHING AND INORM, OUTSTEM = ifmcsm6
spatialsmooth-sess -sf sessid -df sesspar -fwhm 6 -i fmc -o ifmcsm6

# CHECK ALIGNMENT OF RUN 004 VS. 009 WITH TKREGISTER2 - LOOKS BAD
tkregister2 --targ bold/004/fmc.bhdr --mov bold/009/fmc.bhdr --regheader
--reg /tmp/junk.reg

# RUN SPMREGISTER ONCE FOR ALL RUNS TOGETHER DESPITE THAT ALIGMENT APPEARS
BAD
spmregister-sess -sf sessid -df sesspar -funcstem fmc

# CHECK REGISTRATIONS (ONLY ONE bold/register.dat FILE) - LOOKS OK FOR
BOTH, AND VERY SIMILAR FOR RUNS 004 AND 009???
tkregister-sess -sf sessid -df sesspar -funcstem fmc -run 004 &
tkregister-sess -sf sessid -df sesspar -funcstem fmc -run 009 &

---
Also, the defaults for spmregister-sess and tkregister-sess funcstems are
"f". I hope, because my setup does not overwrite the mc-sess output with
the output of spatialsmooth-sess, that I am correct in using the "fmc"
stem instead of "f"? If I have understood corectly, this has the advantage
that I can register motion corrected but not spatially smoothed functional
data, which might(?) at least theoretically give better results than
registering functionals without motion correction... though the advantage
might be too small to be relevant compared to less than perfect
registration accuracy. Any thoughts regarding this? I tried the
registration with the stem "f" as well, and the problems remained the
same, so at least this does not seem to be the cause.

Thanks,

Tommi



hi doug

i think i have actually already done what you suggest as my bold directory
consists of all the retinotopy runs (in subdirs 001-010). this is the 'ls'
of
the bold directory:

001/  003/  005/  007/  009/  register.dat  same-sess-reg.dat  seq.info
002/  004/  006/  008/  010/  rtopy/        scripts/

i ran the motion correction from the study directory as:
mc-sess -sf sessid -df sesspar
and it completed successfully.

-so will that have aligned all the runs together? if so, what can explain
the
fact that the field sign map is not continuous when overlaid on the cortex
and
shows gaps in the blue/yellow colouring?

thanks!

jane


In message <[EMAIL PROTECTED]> Doug Greve
<[EMAIL PROTECTED]> writes:

You can try putting all the runs into a single bold directory. The
motion correction will (do it's best to) align them.

doug






Jane Aspell wrote:

Hi

My question was asked last year by Tommi Raij (see email pasted below)
but I
couldn't find a reply to it in the archives. I am analysing retinotopy
data
that was collected over several sessions but I cannot see how to
register
scans from multiple sessions together, and to the subject's anatomical
scan.
Although Fs-Fast appears to combine the data from multiple sessions
during the
retinotopy analysis it only seems to be possible to use one
registration file
(register.dat) when overlaying the results onto the anatomical. I would
have
thought that registering scans from multiple sessions together would be
a
feature that many people would require. Is there anyway to do it? Tommi
gives
some possible methods in his email below.
When I do try and overlay my data onto a surface I see 'gaps' in the
blue/yellow colouring of the fieldsign map overlaid onto the cortical
surface.
I wonder if this could be due to the inaccuracy of the registration
given that
I only used the register.dat from the registration of the first
session.
hope that makes sense!
i'd be grateful for any help with this!

Jane





--
Douglas N. Greve, Ph.D.
MGH-NMR Center
[EMAIL PROTECTED]
Phone Number: 617-724-2358
Fax: 617-726-7422



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Tommi Raij, M.D., Ph.D.
MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging
Bldg 149, 13th St
Charlestown, MA 02129
U.S.A.

[EMAIL PROTECTED]




--
Douglas N. Greve, Ph.D.
MGH-NMR Center
[EMAIL PROTECTED]
Phone Number: 617-724-2358 Fax: 617-726-7422

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