help > Error in Field Map correction using 7T fMRI dataset
Nov 16, 2023  01:11 PM | Akhil Ratan Misra
Error in Field Map correction using 7T fMRI dataset

Dear all, 

I am trying to perform field map correction on the recently acquired 7T fmri dataset for a single subject. The toolbox works fine without adding the field map images, but when I add do add them using the following methods:

  • Create "Secondary Dataset #2(fmap)" 

  • add 1 Magnitude and 1 Phase image in order

  • choose the pre-processing pipeline to create Voxel Displacement Maps using field maps.

I get the following error:


Error using sqrtm
Matrix elements must be finite.

Error in pm_segment>get_p (line 581)
 dst = (cor-ones(size(cor,1),1)*,i)')/sqrtm(,:,i));

Error in pm_segment>run_segment (line 364)
 [P,ll0] = get_p(cor,msk,s,sums,CP,bf);

Error in pm_segment (line 119)
[CP,BP,SP] = run_segment(CP,BP,SP,VF,sums,x1,x2,x3);

Error in pm_brain_mask (line 48)

Error in FieldMap (line 1611)
 IP.uflags.bmask = pm_brain_mask(IP.fmagP,IP.mflags);

Error in FieldMap_create (line 146) = FieldMap('CreateFieldMap',IP);

Error in conn_setup_preproc (line 3385)
 VDM = FieldMap_create(vfmap,{filename},pm_def); %[ET1,ET2,0,ERT,-1]

Error in conn (line 1386)

Error in conn_menumanager (line 124)
SPM12 + DAiSS DEM FieldMap MEEGtools
Matlab v.2023b
project: CONN22.a


I would appreaciate any help regarding the issue, if I am doing something wrong or there is some other error. I am attaching screenshot for reference.