Thank you for your reply. I left the machine on overnight and it had managed to complete the job in about two hours. However the results are rather bizarre (see attached). The SPM8b seems to have imported Dicom images correctly as it can in the attached file. Am I doing something silly? Could it be that the dataset are incorrect?
Bahman
Norfolk & Norwich University Hospital NHS Trust
Cloney Lane, Norwich
NR4 7UY, United Kingdon
Tel: 01603 286178
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Kathy Pearson
Sent: 14 November 2008 17:47
To: [log in to unmask]
Subject: Re: [SPM] SPM8b segmentation and structural volume size
Bahman,
It could depend on your combination of MATLAB version, OS, and hardware. I
noticed a similar problem in SPM2/SPM5 for normalization and smoothing on
64-bit Linux with MATLAB 7.5, taking over an hour on my system. For me, the
more files in a directory, the longer these steps take. The slow-down may
be due in part to repeated references to the "exist" function before a new
file is created. Reducing those "exists" calls helped me by a factor of 2
or 3, but what I finally had to do to make this go at a reasonable speed was
to create a special directory to hold only the files to be worked on, smooth
or normalize, then move them back to the original directory when processed
-- done in just a few minutes. However, some other scheme may better suit
your particular case.
Kathy Pearson
UAB Psychology
________________________________________
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On
Behalf Of KASMAI BAHMAN (RM1) Norfolk and Norwich University Hospital
Sent: Friday, November 14, 2008 10:54 AM
To: [log in to unmask]
Subject: [SPM] SPM8b segmentation and structural volume size
I am a newbie in fMRI. We have just activated the fMRI functionality on our
Siemens Avanto 1.5T machine and have carried out our very first finger
tapping experiment! The structural image data size is 256x256x176 with
pixel dimension of [0.9766 0.9766 1] and the functional 64x64x34 with
pixel dimension of [3 3 3.75]. The segmentation process on SPM8b takes
longer than I can bear waiting for it to complete! I have waited for an hour
of going over 1500 iterations with no convergence in sight! Am I doing
something silly? Any help on this would be really appreciated.
Bahman
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