Ambellan, Felix Paul
[VerfasserIn]
;
male
[MitwirkendeR];
Schütte, Christof
[MitwirkendeR];
Pennec, Xavier
[MitwirkendeR]
Efficient Riemannian Statistical Shape Analysis with Applications in Disease Assessment ; Effiziente Riemannsche Statistische Formanalyse mit Anwendungen in der Erkrankungsbewertung
Titel:
Efficient Riemannian Statistical Shape Analysis with Applications in Disease Assessment ; Effiziente Riemannsche Statistische Formanalyse mit Anwendungen in der Erkrankungsbewertung
Beteiligte:
Ambellan, Felix Paul
[VerfasserIn]
Erschienen:
Freie Universität Berlin: Refubium (FU Berlin), 2022
Anmerkungen:
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Beschreibung:
In this work, we address the challenge of developing statistical shape models that account for the non-Euclidean nature inherent to (anatomical) shape variation and at the same time offer fast, numerically robust processing and as much invariance as possible regarding translation and rotation, i.e. Euclidean motion. With the aim of doing that we formulate a continuous and physically motivated notion of shape space based on deformation gradients. We follow two different tracks endowing this differential representation with a Riemannian structure to establish a statistical shape model. (1) We derive a model based on differential coordinates as elements in GL(3)+. To this end, we adapt the notion of bi-invariant means employing an affine connection structure on GL(3)+. Furthermore, we perform second-order statistics based on a family of Riemannian metrics providing the most possible invariance, viz. GL(3)+-left-invariance and O(3)-right-invariance. (2) We endow the differential coordinates with a non-Euclidean structure, that stems from a product Lie group of stretches and rotations. This structure admits a bi-invariant metric and thus allows for a consistent analysis via manifold-valued Riemannian statistics. This work further presents a novel shape representation based on discrete fundamental forms that is naturally invariant under Euclidean motion, namely the fundamental coordinates. We endow this representation with a Lie group structure that admits bi-invariant metrics and therefore allows for consistent analysis using manifold-valued statistics based on the Riemannian framework. Furthermore, we derive a simple, efficient, robust, yet accurate (i.e. without resorting to model approximations) solver for the inverse problem that allows for interactive applications. Beyond statistical shape modeling the proposed framework is amenable for surface processing such as quasi-isometric flattening. Additionally, the last part of the thesis aims on shape-based, continuous disease stratification to provide means that ...