Hello,

 

 

I apologize for asking such a basic question, but I can’t find the right tool to interpolate a NIFTI brain volume (or DICOMs) into the raster coordinates of a second volume.  I simply want a naive interpolation into the second volume’s coordinate system without performing registration. For my application I do not want to actually register the two volumes, just interpolate/resample.

 

I tried using mrivol2vol.m in Matlab but it crashes because it can’t find the field ‘mov.vox2ras0’ in my NIFTI headers (I use either mri_convert or dicm2nii to convert Siemens DICOMs to NIFTI). 

 

I then tried manually calculating the raster coordinates for the two volumes by creating integer voxel coordinates for (i,j,k) and then multiplying them by the NIFTI vox2ras matrix to get (x,y,z).  I then use ‘scatteredInterpolant’ in Matlab to interpolate one volume into the second volume’s coordinate system, but this has only worked for me some of the time.  I have been able to interpolate 2D axial MRI slices into an oblique 2D coordinate system, but I’m having trouble with 3D acquisitions like MPRAGE, etc.

 

Does anyone know of a “foolproof” and simple standalone tool for this task (ideally for Matlab)? 

 

 

--- Jason

 

 

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Jason Stockmann

Instructor in Radiology

Martinos Center for Biomedical Imaging

Massachusetts General Hospital 

Charlestown, MA 02129

jstockmann@mgh.harvard.edu

+1 315 450 3309