[Mristudio-users] New to the program

[susumu]

Dear Tapan,

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I write to you with only a few hours of experience with the program under my
belt. The manual which you posted alongside the software is helpful in
knowing how to open files and view them. For the purposes of learning how
the program works, I downloaded the data set 01_020729_31.rec. Initially, I
was able to boot up the program and load the data set via file ->
dtimapping. Using the gradient posted next to the data set on your demo data
database, and leaving all other settings as they were, I was able to bring
up the axial, sagittal, coronal, and 3-d views of the .rec file. Next, under
the dtimap tab, I clicked "tensor, color map, etc." to come up with the
different maps. Once this was completed, I was able to view the different
maps, but this is where my problems began. 
As I stated earlier, I am very new to this field, and thus am at a loss when
it comes to actually interpreting the data. 
For this reason, I am contacting you to ask whether you have some
documentation on how to "read" all the various DTI maps that this program is
capable of creating, along with a glossary which explains every term used in
the program. For me to create maps and not know what I am looking at
presents a problem that, hopefully, you can help me with. I have looked
through the user manual that is on your webpage, and while it is very
helpful in utilizing the program itself, it does not help me interpret the
images. For example, I am completely unaware how to find within what area of
the brain the diffusion is higher or lower than normal, or even know what
normal is for that matter. 
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As you might have already noticed, the manual assumes that readers have a
fair amount of knowledge about DTI. I recommend you to go over several
papers or textbooks to familiarize yourself to the concept of DTI and tensor
calculations. All the names such as FA, RA, VA, CL, CP, and trace follow
widely used conventions. My recommendation is, of course, "Introduction to
Diffusion Tensor Imaging", from Elsevier, which is written for people who do
not have any background in DTI. There is detailed explanation about the
meaning of the contrasts and how to interpret them. I hope it will be of
help.


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Finally, I was wondering if you could tell me that after creating the
"tensor, color maps etc," where I can view the data this calculates, and
what those figures mean. 
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After the tensor calculation, please go back to "image" tab in the right
bottom corner. Within the tab, you can find a pull-down menu in which you
can find a list of new images calculated by the tensor fitting.

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Also, just as a side note, under the dtimap whenever I click any of the
buttons under "calculation," 40% of the time it causes the program to
severely stall and/or crash altogether.
I really appreciate your help in this matter, and hope to soon become
knowledgeable in this area with your aid. So if there is some documentation
explaining every single in and out of what DTI images are, show, and help
with, it would be incredibly useful to me. 
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Most of the clash is caused by memory shortage. The best way is to use the
64-bit operating system. Even if you have more than 2GB of RAM, the 32-bit
system can allocate only up to 1.5GB to a single program. To check if the
memory is the problem, you can limit the number of slices to be calculated.
For example, if you have 50-slice data, you can divide the data into slice
0-24 and 25-49. If this approach works, it tells you have the memory
problem.
 
Susumu