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<TITLE>problems with segmentation</TITLE>
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<P><FONT SIZE=2>Hi there,<BR>
<BR>
<BR>
I am having trouble segmenting an MRI scan using volumesegment on a realigned scan (obtained by volumerealign). Actually, I think this not really a fieldtrip but a spm problem. It seems there are nans or infs in some covariance matrix calculated by spm_segment, but honestly, I don't really see through this. Strangely, it did work once but then found no gray nor white matter but only CSF. Maybe it depends on how I choose the fiducials... If someone has any experience with this I would be really glad for any clue, as I am completley stuck. Thanks in advance! Here's the code and the error message:<BR>
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<BR>
addpath('/data/apps/spm/spm2')<BR>
cd('/net/avidya/storage/home/jan/seidel_dicom/S00002/SER00002');<BR>
mrifilename = 'I00001';<BR>
mri = read_mri(mrifilename);<BR>
<BR>
<BR>
cfg=[];<BR>
cfg.interactive='yes';<BR>
seg_mri=volumerealign(cfg,mri);<BR>
cd('/net/avidya/storage/home/jan/seidel_dicom/mat_anatomy_files');<BR>
save mri_realigned mri<BR>
<BR>
<BR>
cfg = [];<BR>
cfg.template = '/data/apps/spm/spm2/templates/T1.mnc';<BR>
cfg.coordinates = 'ctf';<BR>
cfg.write = 'no';<BR>
cfg.name = 'temp';<BR>
[segmentedmri] = volumesegment(cfg, mri);<BR>
<BR>
<BR>
??? Error using ==> schur<BR>
Input to SCHUR must not contain NaN or Inf.<BR>
<BR>
Error in ==> sqrtm at 33<BR>
[Q, T] = schur(A,'complex'); % T is complex Schur form.<BR>
<BR>
Error in ==> spm_segment>get_p at 552<BR>
dst = (cor-ones(size(cor,1),1)*CP.mn(:,i)')/sqrtm(CP.cv(:,:,i));<BR>
<BR>
Error in ==> spm_segment>run_segment at 335<BR>
[P,ll0] = get_p(cor,msk,s,sums,CP,bf);<BR>
<BR>
Error in ==> spm_segment at 106<BR>
[CP,BP,SP] = run_segment(CP,BP,SP,VF,sums,x1,x2,x3);<BR>
<BR>
Error in ==> ft_volumesegment at 176<BR>
spm_segment(Va,cfg.template,flags);<BR>
<BR>
Error in ==> volumesegment at 17<BR>
[varargout{1:nargout}] = funhandle(varargin{:});<BR>
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