A system is considered for segmenting noisy intensity images and consequent three-dimensional object reconstruction from a set of planar contours. A new semiautomatic method for the extraction of contours from a sequence of cross-sectional images based on an active contour model (ACM) is proposed. The dynamic ACM proceeds along the sequence of cross-sections following a non-rigid motion, in accordance with the organ boundary. Image texture information is also employed in the model. Problems associated with topological reconstruction from planar contours are addressed, and several criteria promoting semi-automatic topological reconstruction are introduced. The proposed system is successfully applied to the processing of real data related to animal embryonic organs, proving that the system allows detailed modelling of irregular objects. The reconstructed models can be observed in wire-frame, solid, transparent or stereoscopic semi-transparent format. The human-computer interaction implemented in the procedure assists with problems of feature identification and object manipulation about an arbitrary axis.