Support of 3D image split in multiple DICOM files

[korbinian90]

Our application is DICOM MRI data from Siemens Scanners. The DICOM files contain 1 slice each, but we have 3D,4D,5D data sets. So a data set is split in multiple files.

It would be great to read in all DICOM files from one folder and merge them to a higher dimensional image. (This can be possible saved afterwards in Nifti format, which is receiving an integration to Images.jl)

The DICOM headers are all nearly identical, only slicenumber, echonumber, timepoint etc. changes. This information could be stored with ImageMetadata.jl. (compatible with other medical standards)