Dear expert,

DICOMs of our 4D functional MRI scans are mostly stored as single slice DICOM files. When using these single slice DICOM files as input for dcm2niix, I get NIFTIs of each dynamic seperately. However, for processing purposes, I would like to get a 4D NIFTI with all dynamics. Adding option -m seems to do the trick:
dcm2niix -o outputfolder -m y inputfolder 
However, I'm wondering if this is the best approach, since this function seems to force a merge and the merge is meant for 2D slices (and not necessarily 3D data; based on the description of the -m option) 

Kind regards and thank you in advance for the assistance,
Manon

This question is underspecified. It soulds like you have enhanced DICOM data, which suggests you have a Canon, Philips or Siemens XA scanner - so the question is which one? My first guess is this is a system running the emergent Siemens XA, and you will need to get the development build of dcm2niix to support the new features. You can get it by going here
  https://ci.appveyor.com/project/neurolabusc/dcm2niix
selecting your operating system (windows, Linux or MacOS) and downloading the artifact. This new development version will being report v1.0.20230320


Alternatively, you can run fslmerge.