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Hello, I found some inconsistencies when comparing the volume of a cluster shown in SPM and marsbar. When I want to investigate a functional cluster determined by a specific contrast I chose, I put my cursor on the local maximum of that cluster and by clicking on "current cluster" I can see how many voxels this cluster contains. E.g. in one case, this cluster contains 52 voxels. When I want to make this cluster my ROI, I just write this cluster using marsbar. However, when I then look at that written ROI (of the same cluster) using the marsbar function "View", it says that the volume of this ROI is 3564 mm. Interestingly, the voxel size we used was 3 mm, thus one voxels should have a volume of 27 mm, i.e. the whole cluster/ROI should have a volume of 1404 mm. Can anyone tell me, if this volume display in marsbar using "View" does make sense at all and how it actually works? Visually, it seems to be exactly the same cluster shown by "View", which I chose before using "Write ROI". Anyhow, this volume size given by marsbar "View" should be a cubic number when divided by the number of voxels (3564 mm/52 voxels = 68.538), which it is not. So, I am just very confused how this volume size refers to my ROI and how it should make sense. I would be glad if anyone could help. Thanks a lot, Svenja