We have proposed a new highly deformable surface model to recover shapes from 3D biomedical images. Its geometry is explicit and defined by a triangulated mesh with distance constraints (as opposed to implicit level-set techniques). Simple distance criteria and local mesh reconfigurations ensure the model keeps a correct topology wrt its geometry. Experiments on various kinds of images have shown the interest of the approach.
cube animation (2.2 Mo). | The volumetric image is a potential field representing a cube in space. The model is looking for iso-surface 0.5 in the field. Curvature constraints are progressively increased. | ![]() | ![]() |
chain animation (0.6 Mo). | The volumetric image is a potential field representing two intertwined torii. The triangulated surface is initialized as a big bubble around the torri. Its shape, at the beginning homeomorph to a sphere, is homeomorph to two torii at the end of the deformation process. | ![]() | ![]() |
chain-grid animation (0.6 Mo). | The volumetric image is a potential field representing two intertwined torii. The triangulated surface is initialized as a set of 1000 small bubbles scattered in the image. The deformation process transforms the triangulated surface into two intertwined torii. | ![]() | ![]() |
skel-dir-1 animation (1.0 Mo). | The volumetric image is a human head CTscan. The skull can be defined as an iso-surface within this image. Internal constraints are added to smooth the surface. The triangulated surface is initialized as a bubble embracing the image (with about 140000 vertices). | ![]() |
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skel-pyr-1
animation (1.0 Mo). skel-pyr-2 animation (1.0 Mo). | Same image as above. The triangulated surface is initialized as a bubble embracing the image (with only 3000 vertices). It first evolves in a coarse approximation of the image. A sketch of the skull is thus quickly extracted. Then the surface is globally refined and it evolves in a finer representation of the image. After this coarse-to-fine approach to the shape recovery problem, the surface has about 130000 vertices. | ![]() |
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angio-pyr animation (2.5 Mo). | The volumetric image is a phase contrast MR angiographic image highlighting the brain vessels. The surface is initialized as a bubble embracing the image (with about 3000 vertices). A coarse-to-fine approach to the shape recovery problem induces a fast sketch of the main vessels. Secondary vessels are extracted during a second phase (after a surface refinement). | ![]() | ![]() |
Lachaud99a , Lachaud98b , Lachaud96a , Lachaud96c , Lachaud96d , Lachaud95 , Lachaud94
J.-O. Lachaud and A. Montanvert. Deformable Meshes with Automated Topology Changes for Coarse-to-fine 3D Surface Extraction. Medical Image Analysis, 3(2):187-207, 1999.
[BibTeX reference] [paper PS gzipped] [Medical Image Analysis (Elsevier)]
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