Seperate 2 series with the same series UID

Hi all,
Whe I upload DICOM series into ITK SNAP, ITK-SNAP succceded to seperate a single slice that was not related to a series that was saved as the same UID.
A dicom viewer Radient, didn’t suceed to seperate them.
Does anyone knows what does ITK-SNAP based on, which DICOM tags, to seperate a non related slice?


What ITK-SNAP uses seems to be here.

Thank you! This is very helpfll!