<div dir="ltr">Hello all,<div><br></div><div style>Where could I find an up to date listing of the which regions correspond to each ROI of the atlases - specifically with regard to the Brain Parcellation Maps?</div><div style>
<br></div><div style>Thanks,</div><div style>Raag</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Mar 6, 2013 at 9:56 PM, Susumu Mori <span dir="ltr"><<a href="mailto:susumu@mri.jhu.edu" target="_blank">susumu@mri.jhu.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
There are several types of WMPM. Actually our newer version of parcellation maps include gray matter structures too.
<div>So, we are now calling it Brain Parcellation Maps (BPM).</div>
<div><br>
</div>
<div>There are two type of parcellation maps; population-averaged and single-subject.</div>
<div><br>
</div>
<div>ICBM-DTI-81 atlas is a population-averaged atlas, which has WMPM. Because it is a population map, it is not a real brain. After averaging 81 subjects, many structures with high anatomical variability smeared out and not definable anymore. For example,
the fine white matter branches into the cortex disappear. Therefore, we can define only the core of the white matter. The WMPM contains structural definitions of only these core WM regions.</div>
<div><br>
</div>
<div>In the averaged FA/color maps, you can clearly see core WM structures like the internal capsule. We manually defined these structures. As you approach to the cortex, we find pixels which are 100% WM in all 81 subject as well as pixels which are only 50%
WM (WM in 40 subjects and other 40 subjects are the cortex). We can threshold the population averaged map at 90, 80, 70, and 60%. As the % goes up, the defined WM shrinks. If you superimpose one of the WM structures with 90% threshold on your subjects (of
course, after normalization), it is highly likely that this ROI defines almost pure WM with a small contamination of the cortex.</div>
<div><br>
</div>
<div>Does it make sense?<div class="im"><br>
<br>
<div class="gmail_quote">On Wed, Mar 6, 2013 at 10:59 AM, Shaimaa Abdelsattar <span dir="ltr">
<<a href="mailto:shaimaa96@hotmail.com" target="_blank">shaimaa96@hotmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>
Could you please tell me the difference between the different types of WMPMs. I found what is called WMPM 80 % or etc.....<br>
<br>
Thanks<br>
<br>
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