<div dir="ltr">Hi Santosh,<div><br></div><div>I want to explain the way we define white matter structures.</div><div>First, let me use the analogy to geological maps. If you open a map of your city, there are two types of information; city and county boundaries and roads. The former is defined by locations and boundaries. The latter, say Route 40, doesn't belong to any specific locations.</div>
<div><br></div><div>When we define white matter structures, one way is based on locations. Many classical names of white matter structures are based on locations. For example, the posterior limb of the internal capsule is the white matter region between the thalamus and the putamen/GP. Our BPM is based on this type of classical "location" definitions of various WM and GM structures. Of course, many structures with specific names, such as the corona radiata, do not have clear definitions about their boundaries. So, we had to use our best, but subjective judgment. Once, somehow, boarders are defined, you can use the BPM as a criteria to reproducibly define the structures.</div>
<div><br></div><div>To answer your question, the BPM defines almost the entire brain WM into one of the labels.</div><div><br></div><div>Another way to define WM structures is based on tractography. This is similar to the road information in a map. For example, we can define the corticospinal tract (CST) that connects the motor cortex and the brainstem. The resultant streamline pass through the corona radiata, the internal capsule, the cerebral peduncle, but it doesn't belong to any of these. </div>
<div><br></div><div>If we consider both BPM and tractography are the tools to define ROIs, we have two different ways to group voxels inside the WM. Depending on the brain abnormality, one way could be more sensitive than the other.</div>
<div><br></div><div>In our atlas, more than 50 "routes" are predefined based on tractography results of 20 - 30 normal subjects. You can use them as ROIs, just like you use the BMP as ROIs. This tractography-based "route" ROIs, however, do not cover the entire brain.</div>
<div><br></div><div>Susumu</div><div><br></div><div><br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Mar 27, 2013 at 8:02 PM, Santosh Yadav <span dir="ltr"><<a href="mailto:santoshyadav20076@gmail.com" target="_blank">santoshyadav20076@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><font>Hi MRIStudio experts,<br><br>I have one question regarding JhuMniSSTypeIIROI map. Is this ROI map
includes the entire structure/track or partial structure/track for
quantification of DTI matrices, for corticospinal tract and fornix?<br clear="all"><br><br>With best Regards,</font><br>
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