Hi Jessica,
the 1.5t scan looks kind of washed out and low contrast, but of course it's hard to tell from an image. The 3T looks much crisper. Were the sequence parameters matched? I'm not sure what you're trying to show with this. The 3T multi-channel scan will have a much, much higher SNR than the 1.5T single channel, so the results will not at all be comparable.
Bruce
On Thu, 23 Jun 2011, Jessica Liu wrote:
Looking at the scans (attached, 3T on the left and 1.5T on the right, yellow
hippocampus), I think you've made a good point. More comments are much
appreciated, thanks!
Jessica Liu
2011/6/23 Pedro Paulo de Magalhães Oliveira Junior <ppj@netfilter.com.br>
This is not normal. Maybe you should check the aseg volume for
improper segmentation.
On Thu, Jun 23, 2011 at 19:27, Jessica Liu <jessicaliu92@gmail.com>
wrote:
Hi everyone!
I'm currently a summer student working at a lab which uses
Freesurfer to measure hippocampal volumes. I noticed that
scanning the same patient first on a GE 3T (Multi-channel head
coil) and then a GE 1.5T (single-channel head coil) 24 hours
later resulted in a 30% increase in the left hippocampus volume
and a 18% increase for the right hippocampus based on the values
in aseg.stats. Can anyone please comment on this and explain
the large discrepancies? Thanks!
Jessica Liu
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