Question on qform/sform values after correction

[Alexis Bonis]

Hello Frank,

While I was correcting, some data with DSI (TOPUP/EDDY and Motion Correction), I saw that the values of the sform matrix in the header of the corrected file are only 0, except for the translation on the X axis (which is equal to 75), the translation on the Y axis (which is equal to 41), and the diagonal (which values are -1, -1, 1 and 1 respectively).

The qform matrix is also not equal to the sform matrix and only have 0 except for it's digaonal too (which values are -1, 1, -1 and 1 respectively).

And then, I saw that for all my different subjects, they all have these same values in their qform/sform matrixes.

Do you have any idea where these values ​​might come from? And why do all subjects have these same values?

Thank you.

Best regards,

Bonis Alexis

[DSI Studio]

For any NIFTI images saved by DSI Studio, they will be rotated to LPS orientation.