Dear experts,
when running the second level analysis for some fMRI data, the spm_check_orientations function is called. I receive the error:
Running 'Factorial design specification'
Mapping files :
** The images do not all have same orientation and/or voxel sizes. **
...
In preprocessing, I am using the SpaceTimeRealign algorithm [Roche2011] . When I look at the orientation matrices, I detect errors at the 10⁻3 level, while and SPM triggers an error because of the line if any(any(abs(diff(matx,1,2))>1e-4)).
Example:
...
[-3 0 0 93; 0 3 0 -129; 0 0 3.99 -75.81] /scratch/ws/0/bernardo-asdtom/asdtom/firstlevel_output/dartel4d/64-22-003_1/contrasts/_modelname_VID_PTR_Block/_fwhm_8/con_0007.nii
...
[-3 0 0 93; 0 3 0 -129; 0 0 3.98959 -75.8021] /scratch/ws/0/bernardo-asdtom/asdtom/firstlevel_output/dartel4d/64-22-337_1/contrasts/_modelname_VID_PTR_Block/_fwhm_8/con_0007.nii
...
The scans where the errors are above the 10⁻4 threshold were obtained with a different scanner. How would you recommend to proceed? should I really worry about these small but not small enough differences? I am also running the analysis on a computing cluster and using the SPM12 standalone, so I cannot edit the spm_check_orientations.m file and set a more permissive threshold like 10⁻3.
Please let me know in case you need further information. Thank you in advance for any help!
Fabio Bernardoni
Dr. Fabio Bernardoni
wiss. Mitarbeiter
Division of Psychological & Social Medicine and Developmental Neurosciences
http://www.transdenlab.de/; http://www.uniklinikum-dresden.de/psm
+49 (0351) 458-5245
Universitätsklinikum Carl Gustav Carus
an der Technischen Universität Dresden
Anstalt des öffentlichen Rechts des Freistaates Sachsen
Fetscherstraße 74, 01307 Dresden
http://www.uniklinikum-dresden.de
Vorstand: Prof. Dr. med. D. M. Albrecht (Sprecher), Katrin Erk
Vorsitzender des Aufsichtsrates: Prof. Dr. G. Brunner
USt.-IDNr.: DE 140 135 217, St.-Nr.: 203 145 03113
http://www.uniklinikum-dresden.de
Vorstand: Prof. Dr. med. D. M. Albrecht (Sprecher), Wilfried E. B. Winzer
Vorsitzender des Aufsichtsrates: Prof. Dr. G. Brunner
USt.-IDNr.: DE 140 135 217, St.-Nr.: 203 145 03113
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