Hi Doug -
This is a new feature, just added to the Nightly. There is a release planned in the next few weeks. It might be possible to use the newer code with the older release, I didn’t check.
Is there any chance you are a python programmer? Neither Andrey nor I have a particular use case for 4D nifti files but we added minimal support without planning to take on all possible uses. if you wanted to customize the interface to suit what’s most convenient that would be great.
Right now the code only tries to read a 4D nifti when there’s one file in the selected folder, but this could obviously be generalized to loop through and load all the files, but also some logic would be needed to tell when it’s a directory of 3D that should be one multivolume vs. a folder with more than one 4D volume. Perhaps the easiest would be just to add a file browser in addition to the directory browser, perhaps with a radio button to select which to use. None of this is especially hard to do, but it would be some work to implement, document, test, etc.