You can specify a beginning and an end to a VOI to restrict it to a certain subset of the volume.
1. Scroll to the location above the Base VOI where you would like to end the VOI.
2. Press Delete.
The VOI is no longer active from that location outwards towards the edge of the volume.
1. Scroll to the location below the Base VOI where you would like to end the VOI.
2. Press Delete.
The VOI is no longer active from that location outwards towards the edge of the volume.