Hi Alex,
unfortunately the current answer depends on what part of the brain you are interested in. For cortex, it appears that the raw CNR of mp-rage is significantly better than the multi-channel (T1/PD/T2*) CNR. On the other hand, subcortically for things like pallidum/putament, the multi-channel segmentation has much higher CNR.
We do have multi-channel aseg segmentation in place, but haven't used it a ton (since we have so much mp-rage data around).
cheers, Bruce
On Mon, 24 Oct 2005, Fornito, Alexander wrote:
Hi, We're about to start a longitudinal study and are keen to get accurate measures of structural change. Currently we are planning to acquire a T1 and T2, and have some spare time for another acuqisition. I've noticed in a recent paper (Fischl, et al (2004) Neuroimage,23, S69-S84) you discuss the benefits of combining T1 and PD images to aid segmentation. Just wandering if there are any plans to incorporate multichannel segmentation into freesurfer, and if so, would you recommed acquiring two T1s and averaging, or a single T1 and PD? Thanks, Alex
Alex Fornito M.Psych/PhD (clin. neuro.) candidate Melbourne Neuropsychiatry Centre and Department of Psychology The University of Melbourne alexander.fornito@wh.org.au
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