The brain VOIs are structurally organized in a tree on the Group tab of the VOI editing page. The selection of a VOI subset is supported by a dedicated user interface illustrated below.
The branches on the top level are the Cerebral cortex, divided into left (L) and right (R) hemispheres, Subcortical regions, Posterior fossa, Ventricles and the White matter, as illustrated in the left panel above. The full tree can be toggled open/closed easily by using the button indicated in the middle panel above. The tree view can be flattened to a simple list using the button at the top, as indicated in the right panel above. The statistics will only be calculated for the selected VOIs.
Tree Manipulations
Branches in the tree can be opened/closed with the little arrows left to the branch names.
Tree Selections
Checked VOIs in the tree structure are overlaid on the image and used in statistics calculation. Simply uncheck any VOI to exclude it. In the example below the FL_mid_fr_G VOI has been de-selected.
If the selection of a branch is removed, all VOIs belonging to it will be de-selected.
The task of selecting parts in the tree is supported by shortcuts in the area below the VOI list:
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Set the selection check of all VOIs |
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Remove the selection check of all VOIs. |
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Save the current selection set to a file. |
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Load a selection set from a file. |
VOI Union
The currently selected VOIs can be combined into a larger structure by the Union button. In the example below the selection was first reset by 
, and then the Frontal_lobe entry in the Left_hemisphere of the Cerebral cortex branch was checked.
Note that in PNEURO the original VOIs are removed during the Union process. This is necessary for partial volume correction to function correctly. However, the VOIs can easily be recovered by stepping to the prior page and activating the Outline button again.