How to calculate the global correlation between two contrasts

Dear Chao-Gan,

Recently I have done a study which includes two datasets (30 patients and 30 controls, and 20 patients and 21 controls, respectively), and the second is the subset of the first. The reviewer required me to report the globle correlation between these two contrasts. However, I have never done such analysis before. Can I use dpabi or any other software to achieve it?




Checking the quality of coregistration


I was wondering if it is possible with DPABI to check the quality of the coregistration somehow? I could only find pictures for checking the quality of the Normalization.




Values of sm* ReOh maps

Dear experts,

I computed ReOh maps for some patients and controls in DPARSFA (running the participants all together, hence with the same processing settings) and got maps where the values are not between [0 1], is this correct? I expect having values between 0 and 1 due to the computation of KCC. I obtain values between 0 and 1.6/1.8.

Please advice if correct,

Thank you,

Kind regards,

Bianca De Blasi

Covariable file

Dear experts.

I am looking for csf and white matter signal covariates and find the attached file in ...globalCovs folder.

However, the file contained 30 columns and perhaps the last three columns would be meaningful to me.

Please let me know which comumn represents csf, white matter, and global signal.

Best regards,




Which mask to use for smoothness estimation (FWHMx,y,z)?

Dear Chaogan,

My study is to use voxel-based rs-FC measure to perform statistical analysis. That rs-FC measure was generated within a GM mask, so that FC was calculated between any two voxels within the GM.

After statistical analysis,  however, I consider that the whole brain mask, instead of the GM mask, should be used for smoothness estimation (FWHMx,y,z) with 4D residuals.


Gissian random field (GRF) in DPABI for multiple correction

Dear experts,

I used Gissian random field (GRF) in DPABI  for multiple correction when comparing rs FC maps differences between patient groups.


Gissian random field for multiple correction

Dear experts,

I used Gissian random field (GRF) in DPABI  for multiple correction when comparing rs FC maps differences between patient groups.

However, a reviewer suggested "this method (GRF) is based upon the hypothesis that the spatial smoothness of BOLD signal in the whole brain is consistent and the distribution of the spatial autocorrelation function in accordance with specific curve. Practically, the BOLD data is hardly accord with the hypothesis".

How to Set thr in the image caculator?

Dear Dr Yan

         I have several problem which confuse me .

         1. How to set the thr in the image caclator. I gonna set a mask use the expression, (i1<thr)+(i2<thr). I have no idea about the definition of thr. I had ever used the number of Voxels(alpha sim correction) and thr in Viewer. But it doesn't work.

        2.It confuse me that there are many noises in the blank region. 


smoothing, alff and reho

Dear Dr.Yan,

May I ask a simple but sounds stupid question? I know it should do reho before smoothing, but is it possible that calculate alff before smoothing as well? Why?




Mixed effect analysis

Dear experts

In a statistcal analysis of DPABI, a default setting of mixed effect analysis is 2X2. 

What if I want to use mixed effect analysis of DPABI with factors greater than 2? 

Best, Dong Woo 



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