hello, is it possible to see two volumes one over other. like i want to put segmented output result on original images. how to do it using slicer?
Yes, and there are many visualization options. You can overlay any number of segmentations over a grayscale volume, both in slice and 3D views. You can also overlay two grayscale volumes and a labelmap volume in each slice viewer, and display these slices in 3D. You can display grayscale volume using volume rendering in 3D.
Have you completed Slicer introduction tutorials? If you still have questions then let us know.