Hi Susan, if you are not doing a thickness study, then I don't think it will matter much if you have 1 or 2 or 3 T1s. There's not an easy way to compare the recons. You can do a paired difference using 1 T1 vs mult T1s. That will mostly give you bias information, not accuracy or repeatability. doug
On 07/30/2012 01:18 AM, Susan Alice McLaughlin wrote:
Hi Freesurfer experts,
We’ve been collecting structural (1mm isotropic) and functional (2.75x2.75x3mm) data on a Philips 3T scanner using an 8-channel head coil. We are reconstructing each subject’s surface and mapping functional data processed in FSL’s FEAT to the surface. For some subjects, we have only 1 MPRAGE, but for others, we have multiple (2 or 3) MPRAGEs, acquired in separate scanning sessions.
Looking back at the list serve and FSLwiki (http://surfer.nmr.mgh.harvard.edu/fswiki/FsQuizAnswers), it appears that our SNR should be good enough that we do not need -- and perhaps SHOULD NOT use --multiple MPRAGEs when using recon-all. Is there general agreement on this?
How does one go about quantitatively comparing one surface reconstruction derived from 1 MPRAGE to another derived from 2 MPRAGEs?
Thank you,
Susan McLaughlin Doctoral Candidate SPACE Lab (Stimulus-Parametric Imaging of Auditory Cortex) Dept. of Speech and Hearing Sciences University of Washington
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