Hi freesurfers,
Are many groups getting good results from single 1mm isovoxel T1
inputs? Anyone experimented with multispectral input?
We're acquiring a number of participants on a Philips Achieva 2.5
system with 8-ch SENSE coil. Good scans, very little movement. I
realize that the selection of freesurfer inputs and averaging is
empirically driven and idiosyncratic to each scanner/sequence/coil
combination, but I just want to solicit any thoughts about possible
benefit from non-standard sequences. Due to other priorities we are
unable to collect two identical T1s in each study, but this is what we
do get that might aid automated structural segmentation:
- 3D T1 TFE (1 mm3, good contrast among gray, white, and CSF)
- 3D T2 FLAIR (1 mm3, high gm/csf contrast but no gm/wm contrast,
except for wm hyperintensities)
- 3D T1 "FGATIR" (.75 mm3, very high gm/wm contrast but very low gm/
csf contrast)
This last sequence is the one I'm most curious about: might the very
high gm/wm contrast be used to help freesurfer's segmentation? Image
attached, showing a participant's standard 3D T1 TFE on the right and
the high g/w contrast T1 on the left. This paper describes the FGATIR
sequence:
Sudhyadhom, A., Haq, I. U., Foote, K. D., Okun, M. S., & Bova, F. J.
(2009). A high resolution and high contrast MRI for differentiation of
subcortical structures for DBS targeting: The Fast Gray Matter
Acquisition T1 Inversion Recovery (FGATIR). NeuroImage. doi: 10.1016/
j.neuroimage.2009.04.018.
Thanks!
Stephen
--
Stephen Towler
Graduate Student, Neuropsychology
Dept. Clinical and Health Psychology