ImagO Colloquium Medical Imaging Iconic shape models: joint registration, segmentation and atlas construction Prof. Frederik Maes KU Leuven ESAT/PSI - Medical Imaging Research Center In this talk I will give an overview of 20 years of research at the Medical Image Computing group of KU Leuven dealing with iconic models, i.e. image-based representations of photometry, shape and context, such as atlases. Such models are constructed from a set of pre-annotated images and fitted to new images by non-rigid image registration, driven by a suitable similarity measure and regularisation mechanism. Maximisation of mutual information of corresponding voxel intensities proved to be a breakthrough in the field, but in the context of image segmentation, use of more specific object labels in the similarity measure is to be preferred. This naturally leads to a joint segmentation-based registration and registration-based segmentation approach. When extending this idea from the analysis of a single image to multiple images, the construction of a group-specific optimal atlas can be integrated in the solution. By considering that different images in the group may belong to different subgroups (e.g. healthy versus diseased), stratified atlases per subgroup can be constructed that can be interpreted as summaries of morphological differences between subjects at the group level (i.e. imaging biomakers). Our current work focuses on extending this scheme towards longitudinal analysis and construction of multitemporal atlases. The various concepts in this talk are mathematically consistently formulated and solved within a probabilistic framework using the EM algorithm and illustrated for brain MR images. Tuesday 20 January 2015, 13.30 – 14.30 hrs Auditorium, new Q-building (AZU, Heidelberglaan 100, Utrecht) Medical Imaging: ImagO, PhD Programme of the Graduate School of Life Sciences University Medical Center Utrecht – Q02.4.45, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands Tel: +31 88 755 7772, E-mail: info@imago.uu.nl, URL: http://www.imago.uu.nl