Hello Philipp,
Thank you! This is a great help already! I'll check all this info!
Best,
Andreia
Citando Saemann Philipp <[log in to unmask]>:
> Hello Andreia,
>
> much here depends on the scanner and software you use for spectroscopy.
> Generally, for this specific question, I think you might want to ask your
> technical support, too, could be tricky if
> not really available as tool, as often relativ coordinates are given.
>
> Several bits of information are needed:
> - First, the coordinates of a voxel (most times, a specified voxel in one
> of the corners of the spectroscopy 'box'
> are given in one of the spectroscopy data files.
> - These coordinates, however, are probably given in relation to some table
> position.
> - The T1-dataset (or dataset you then want to use for segmentation) also
> contains some absolute coordinates of
> its corner.
> also in relation to a table position.
> - We the segmentated the native T1 (and got GM, WM and CSF in native space).
> - By calculating the relative position of the spectroscopy voxel within the
> T1, we created a binary ROI. This
> is the part where most errors can occur...
> - Within ths ROI, we read out the volumes of the three segmentations and
> calculated percentage CSF etc.
>
> But as mentioned, there might be specific functions to easen that process,
> and it might be wise to
> contact your hardare/software providers, too,
>
> Hope this helps,
> Philipp
>
>
> Tailarach information: the
>
> At 19:18 28.04.2011 +0100, you wrote:
>> Hello all!
>>
>> How can I get the % of the different types tissues inside a spectroscopy
> voxel? My main problem is, how can I define the anatomical ROI from the
> files obtained in the scanner since the anatomical and the spectroscopy
> files are different and independent? I can only see the VOI imposed to the
> anatomical data while in the scannerĀ?s console, I think. Is there a way of
> defining coordinates in the console and then transfer them to FSL?
>>
>> Another problem is, if I do the Talairach transformation (which I'll be
> doing for the group analysis) I will loose the dimensions on which the
> voxel was acquired.
>>
>> IĀ?ve seen many many papers in which this segmentation is done, but I
> still canĀ?t figure out the way to do it.
>>
>> Many questions... IĀ?m just starting to work with this methods.
>>
>> Thank you in advance.
>>
>> Andreia
>>
>>
> Max Planck Institute of Psychiatry
> NMR Research Group
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