Distinguishing between different "volumes" within diffusion series


I am trying to figure out how to distinguish between different volumes within a diffusion series. By “volume,” I mean a collection of DICOM files that collectively make up 1 3D image of the brain. The diffusion data that I am working with (Ax-DWI-PA-40-6) contains 46 volumes for a single series, but I don’t see an attribute indicating which volume the DICOM slice belongs to. Any ideas?

@James_Ko your question is underspecified as you need to know the manufacturer and the software version and mode (e.g. classic versus enhanced DICOM) to determine this. If you can provide the BIDS JSON sidecar created when converting your image with dcm2niix, I might be able to provide some comments. Assuming your data is from Siemens, you may find the private tag ICE_DIMs (0021,1106) useful. For enhanced DICOM, take a look at the Dimension Index Sequence (00209222)