[Freesurfer] PDs?

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