I am using spm12 to prepossess an fMRI data and I do not have the slice acquisition order, I want to check the slice ordering in an image (volume) using SPM , I found a way to do that from the internet "https://en.wikibooks.org/wiki/Neuroimaging_Data_Processing/Slice_Timing" (SPM : Slice timing order inference), and the instructions say:
* Load the image (volume) using "Display" option.
* On the left-side of the windows that shows there is a panel showing the coordinates of the cursor both in voxel (vx) and millimeters (mm).
* In the voxel coordinates change z = 1 and fix x and y.
* Now increase z = 2 to the number of the slices in the volume and the corresponding change in the millimeters coordinates (from the increase on the step we could know the slice ordering ) .
I followed the above steps and I get:
I fixed x = 1, and y = 1, in the voxel coordinates, and i increased z = 1 to 20 (number of slices in my fMRI data) and I get the following numbers in the z coordinate in millimeters:
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z (vx) = 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
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z(mm) = -77.6 -69.6 -61.6 -53.6 -45.6 -37.6 -29.6 -21.6 -13.6 -5.6 2.4 10.4 18.4 26.4 34.4 42.4 50.4 58.4 66.4 74.4
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Slice thickness = 8 mm.
I think from what I got, that the slice acquisition direction is " ascending" (first slice = bottom), is I am right?
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