different scanning parameters

Submitted by Emilia Cheladze on

Hi!

I am doing an analyses on two groups of subjects with data that was acquired with different scanning parameters:

1. TR 2.3, 37 slices, 3x3x3

2. TR 2.3, 34 slices, 4x4x4

What would be the best common voxel size for the analyses? 

To what point should I preprocess the data separately?

Thank you for any hepl in advance,

Emilia Cheladze

Thank you very much for your answer!

If you don't mind I have few follow up questions, though.

1. What exactly happens in DPRSFA when I input the voxel size during Normalization step? Is the image actually resliced (if the input voxel size is different that it actually is) ? If yes, than could you please write what is the interpolation method?

2. If I were to reslice image in utilities>image reslicer when is the best moment to do it? Before/after preprocessing, first level?

3. What the choice of the interpolation method depends on? What would be the one you recommend? 

Emilia Cheladze

Mon, 07/25/2016 - 10:06

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Thank you very much for your answer!

If you don't mind I have few follow up questions, though.

1. What exactly happens in DPRSFA when I input the voxel size during Normalization step? Is the image actually resliced (if the input voxel size is different that it actually is) ? If yes, than could you please write what is the interpolation method?

2. If I were to reslice image in utilities>image reslicer when is the best moment to do it? Before/after preprocessing, first level?

3. What the choice of the interpolation method depends on? What would be the one you recommend? 

1. DPARSFA call's SPM's normalize function. You can find the details at SPM's manual. The interpolation is 4th Degree B-Spline (the default one).

2. You don't need to use Image Reslicer if you set the voxel size in Normalization.

3. I will choose the default one.

Thank you very much for your answer.
Let me ask once again, just to make sure I'm not going to make a mistake. 
Just by inputting the same voxel size (for example 4x4x4 for both data sets) I will reslice the images of one data set and not of the one that was already acquired 4x4x4. Therefore, I will end up having two sets of data acquired with different scanning parameters but in a form that can be analyzed together/compared. Is that correct? 
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