I’ve checked the sample images that were shared in this post.
You can load them by enabling “Advanced” mode and selecting the “… Volume Sequence…” loadables:
Most of the datasets are 4D data sets (3D+t), although most of them just 3-5 slice thick slab (except series 601, which is a bit thicker, as it contains 18 slices). There are also a few flow data sets, which contain 3 sub-sequences (PCA, FFE, and VELOCITY MAP).
I’ve submitted a pull request to the multi-volume importer module, which will change the default behavior so that you will not need to use the advanced mode to load your sequences as thick slabs. It will probably take just a few days to get integrated into the Slicer Preview Release.