Dear Rik, could you please elaborate. See below.
On Wed, 9 Feb 2000, Rik Henson wrote:
>
> > I tried to use slice timing in spm99 for some fMRI data. I expected slice
> > timing in spm99b and spm99 to be similar, but they are not! In spm99,
> > inputs of TR and TA are required, but NOT in spm99b. The version in
> > spm99b is v2.3 and ,in spm99, v2.6.
> >
> > (An earlier post about TA was found in the archive in Sept 99, but
> > generated only one response/follow-up question.)
> >
> > My questions:
> > 1. What is the acquistion time (TA)? Can someone give an example how
> > this is determined?
>
> In simple terms, the TA is the time between acquisition of the first
> slice
> and acquisition of the last slice of one scan, whereas the TR is the
> time
> between acquisition of the first slice of one scan and the first slice
> of
> the next scan (ie TA<=TR). In some acquisition sequences, there is an
> appreciable gap between successive scans (TA<TR) which needs to be taken
> into account in the slice-timing correction.
Is TA not the time between teh start of the first slice and the end of the
last slice of one scan. That would make more sense to me ??
Peter Erhard, Ph.D.
Nuklearmedizinische Klinik und Poliklinik
Klinikum rechts der Isar
Technische Universitaet Muenchen
Ismaninger Strasse 22
81675 Muenchen
Germany
Tel: 49-89-4140 4570
Fax: 49-89-4140 4938
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