Where is the grey matter signal in DPARSF

Submitted by haohaoxuexi on Thu, 11/15/2012 - 21:34

 Hello, everybody,
I have heard that there is grey matter signal in DPARSF result, but I don't know the location. How to get them? Who knows. Please tell me. It is not easy to understand even the most fundamental concept.
Thank you very much!
Xuemin

Forums:

ZangYF

Fri, 11/16/2012 - 00:07

The term "grey matter signal" is not clearly defined. Would you please explain in more details?

haohaoxuexi

Fri, 11/16/2012 - 04:48

Hi, Teacher Zang,
  I learnt from the video course that when we compare AD and NC , we can use the "grey matter signal" as an image covariates to exclude the  influence of the structural atrophy. Then it said there is " grey matter signal" in the DPARSF results. We can obtain from DPARSF processing, but have to reslice to 3*3*3 since the different accuracy . Therefore, how can I get the "grey matter signal".
Am I understood?

Thank you so much for your time. Forgive my hard English. I am working on it.
xuemin

YAN Chao-Gan

Fri, 11/16/2012 - 16:06

Hi,

It's "grey matter density" other than "grey matter signal".

Please find the "wc1*" files within "sub00X" under "T1ImgNewSegment" or "T1ImgSegment". These are the grey matter density files which can be used as covariates.

Best,

Chao-Gan

haohaoxuexi

Fri, 11/16/2012 - 17:25

THANK YOU !
I can't fide the file. Firstly, I thought the file obtained from the "Functional Connectivity" part, global mean -CSF -white matter. But they are "signals".Then I conclude that ,to obtain the "grey matter density", I need to use " T1 image unified segmentation". I used EPI templates, therefore I do not have the files. I shoude arrange my "T1" data. Do I have to repreprocess my data? 
I really appreciate your help. 
Xue

YAN Chao-Gan

Tue, 11/20/2012 - 18:43

 Hi!

What do you want to do?

The global/WM/CSF signal regression in functional connectivity analysis is another thing.

If you want to use grey matter density as a covariate in group analysis, you may need to check "segment" or "new segment".

Best,

Chao-Gan

wuqinjuan1

Sat, 12/01/2012 - 10:44

严超赣老师您好！我们用的是EPI模板，没用T1像做模版，所以没生成wc1文件，那么在做功能连接去除协变量时，是不是灰质体积的影响就不能被去除了呢？谢谢！

YAN Chao-Gan

Sat, 12/01/2012 - 17:48

你好！

上面讨论的不是这个问题。上面讨论的是采用灰质密度做为组分析的协变量。

在做功能连接去除协变量的时候，通常是不会去除灰质信号的（虽然所谓全脑信号大部分是来源于灰质）。全脑信号的MASK是来源于先验MASK，没有T1像也没有影响的。