Abstract. In screening X-ray mammography two different views are captured and analysed of both breasts. In the four X-ray images some special signs are looked for. First the individual images are analysed independently, but good result can be achieved only if joint analysis of the images is also done. This paper proposes a simple procedure for the joint analysis of the breast's two views. The procedure is based upon the experiences of radiologists: masses and calcifications should emerge on both views, so if no matching is found, the given object is a false positive hit. First a reference system is evolved to find corresponding regions on the two images. Calcification clusters obtained in individual images are matched in "2.5 D" provided by the reference system. Masses detected in individual images are further examined with texture segmentation. The proposed approach can significantly reduce the number of false positive hits both in calcification and in mass detection.

Since there are already tools for implementing and managing spatiotemporal data, it is worth elaborating methods for solving inter operability problems. In this paper a spatiotemporal model, PLAT is investigated from this point of view. We describe algoritbms for translating PLAT into other spatiotemporal models. It is also shown that the necessary topological information for building the PLA-or PLAT-Model can be extracted from other constraint and spatiotemporal models. These methods are useful in cases where topological properties have to be discovered, since very fast algorithms are developed in the PLA-ModeI.