From Uncertainties to Statistical Model Building and Segmentation of the Left Ventricle

Reliable segmentation of the left ventricle is a long sought objective in medical imaging for automatic retrieval of anatomical and pathological measurements and detection of malfunctions. In this paper, we propose a novel model-constrained approach to address this task. The method is based on an implicit representation of the shape model used in a shape registration framework with a Thin Plate Spline transform to retrieve possible deformations. The main innovation of our approach resides in the use of uncertainties defined on the registered shape to augment the training set and improve the robustness of the statistical deformable model. We use ICA to reduce the dimensionality of the space of deformations and provide a good separation of the different deformable parts of the heart. Furthermore the estimation of uncertainties is also introduced in the segmentation process which is addressed in a variational framework where prior knowledge and visual support are considered. The method lead to very promising qualitative and quantitative experimental results in CT.