This might not be relevant to the challenge since ventricle segmentation is not part of the task, but after checking some labels, I think it might be under segmented.
Created by Xue Feng xf4j Dear @xf4j,
Thanks for your post and for taking a close look at the segmentations.
The ventricular labels provided were automatically segmented and then manually edited to ensure no overlap with key subcortical structures of Tasks 2a and 2b. Their inclusion is intended to support participants’ segmentation pipelines by helping to disambiguate boundaries for the primary regions of interest, the hippocampus and basal ganglia. Thus, ventricular segmentations may be under-segmented.
We appreciate the feedback and hope this helps contextualize the role of these labels in the overall dataset.
Best,
The LISA 2025 Challenge Organizers