This paper describes a novel approach to surface tracking in volumetri
c image stacks. It draws on a statistical model of the uncertainties i
nherent in the characterisation of feature contours to compute an evid
ential field for putative inter-frame displacements. This field is com
puted using Gaussian density kernels which are parameterised in terms
of the variance-covariance matrices for contour displacement. The unde
rlying variance model accommodates the effects of raw image noise on t
he estimated surface normals. The evidential field effectively couples
contour displacements to the intensity features on successive frames
through a statistical process of contour tracking. Hard contours are e
xtracted using a dictionary-based relaxation process. The method is ev
aluated on both MRI data and simulated data. (C) 1998 Elsevier Science
B.V. All rights reserved.