We investigate how stereo graphics
and haptics can be combined to facilitate the seeding procedure
in semi-automatic segmentation of magnetic resonance angiography (MRA)
images. Real-time volume rendering using maximum intensity
projections (MIPs) has been implemented together with a haptic
rendering method that provides force feedback based on local
gradients and intensity values. This combination allows a
user to trace vessels in the image, and to
place seed-points directly in the 3D data set. Seed-regions
are propagated from the seed-points
according to an algorithm that favors bright voxels.
An experienced user have tested the interface
on whole-body MRA images with promising results.