the easiest thing is just visual inspection. It depends on the coil and
the field strength. We routinely do a single 6.5 minute acquisition with
a 12 channel coil at 3T and it seems fine. You could do test/retest
studies of course, but that will tell you reliability, not sensitivity.
Bruce
On
Mon, 9 Jul 2007, Narly A Golestani wrote:
Hi Bruce,
Thanks for your answers. It actually is for a thickness study. I hope
that one run will be adequate. Are there validity checks for the analysis
output?
thanks again,
Narly.
On Mon, 9 Jul 2007, Bruce Fischl wrote:
Hi Narly,
1) we've run a couple of mdeft and they seem fine.
2) It really depends on the CNR. The tools are much more robust these days,
and a single acquisition is usually fine. It also depends on what you want
to do with the data. If it's just for analysis of functional data then the
requirements are not as stringent as if you want to do a thickness study.
cheers,
Bruce
On Mon, 9 Jul 2007, Narly
A Golestani wrote:
Dear all,
I am a new FreeSurfer user, and have a quick question before beginning to
process T1 data: on the beginners guide (entitled 'Cortical Reconstruction
with FreeSurfer'), it says that the input ought to be from MPRAGE or from
SPGR sequences. 1) Are these the only sequences that FreeSurfer can
process? I have data obtained using a MDEFT sequence, with
fat-insensitive excitation pulses and a FLASH-EPI hybrid readout. 2)
Also, I only have one structural run per brain - but the tutorials /
set-up pages seem to suggest that it is necessary to have 2 structural
runs per brain. I would appreciate more information on the type of T1
input sequences that FreeSurfer can process.
thanks,
Narly.
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Narly Golestani
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