Thank you for your response, but I don't think I have mosaic images. My situation is different and specifically involves 4D flow MRI data:

1. I have 60 separate DICOM files from a Siemens scanner (XA60)
   
2. Each file represents a different slice position (so 60 different slice positions)
   
3. Each file contains all the timeframes for its specific slice position (4D flow acquisition)
   

What I'm trying to do is merge these 60 files into a single 4D volume where:

• The first 3 dimensions are spatial (x, y, 60 slices)


• The 4th dimension is temporal (all timeframes)

When I run dcm2niix, it finds the 60 files but doesn't seem to complete the conversion process.