Dear all,
We applied SPM in the SPECT study. Our data were
formatted as a 3D dataset with 64x64x64 cubic voxels
with 3.5 mm sides. The resolution in a tomographic
slice was measured to be 10.2mm (FWHM). The
reconstructed data sets were post-filtered with a
Butterworth filter, cutoff 1.0 cm-1.
In the SPM analysis, we use 15mm (FWHM) for the
smoothing procedure. But in the final output, the FWHM
value SPM gave were between 25mm to 30mm, which seems
too large for me, although it does not equal to the
imaging resolution.
Is it possible to explain to me how SPM calculate the
FWHM, what it represents and how many factors might
influence the calculation. also,what kind of FWHM
value in the final output is reasonable for SPECT
analysis?
Best regards
chaorui
__________________________________________________
Do You Yahoo!?
Yahoo! - Official partner of 2002 FIFA World Cup
http://fifaworldcup.yahoo.com
|