1. A method for segmenting significant regions in measurements of a target body, comprising the steps of: receiving reference data comprising a plurality of values each associated with a plurality of coordinate values for spatial or temporal dimensions based on a first measurement mode of a reference body; receiving reference segmentation data comprising a plurality of coordinate values for spatial or temporal dimensions for each vertex in a plurality of vertices that indicates a boundary of a physical component of the reference body in the same coordinate frame as the reference measured data; receiving target data comprising a plurality of values each associated with a plurality of coordinate values for spatial or temporal dimensions based on a second measurement mode of a target body; automatically determining a particular transformation to maximize a similarity measure between the reference data and the target data; transforming the reference segmentation data using the particular transformation to produce transformed segmentation data that indicates in the target data a boundary of the physical component of the target body, and adjusting a coordinate for a vertex of the transformed segmentation data based on a plurality of gradients in values of the target data in a vicinity of the vertex.