Evaluation of mesh morphing and mapping techniques in patient specific modelling of the human pelvis

Abstract

Robust generation of pelvic finite element models is necessary to understand variation in mechanical behaviour resulting from differences in gender, aging, disease and injury. The objective of this study was to apply and evaluate mesh morphing and mapping techniques to facilitate the creation and structural analysis of specimen-specific finite element (FE) models of the pelvis. A specimen-specific pelvic FE model (source mesh) was generated following a traditional user-intensive meshing scheme. The source mesh was morphed onto a computed tomography scan generated target surface of a second pelvis using a landmarked-based approach, in which exterior source nodes were shifted to target surface vertices, while constrained along a normal. A second copy of the morphed model was further refined through mesh mapping, in which surface nodes of the initial morphed model were selected in patches and remapped onto the surfaces of the target model. Computed tomography intensity-based material properties were assigned to each model. The source, target, morphed and mapped models were analyzed under axial compression using linear static FE analysis, and their strain distributions were evaluated. Morphing and mapping techniques were effectively applied to generate good quality and geometrically complex specimen-specific pelvic FE models. Mapping significantly improved strain concurrence with the target pelvis FE model.

A Cortical Thickness Mapping Method for the Coxal Bone Using Morphing

“…The ability to predict pelvic fracture using FEA is largely contingent on an accurate representation of the cortical layer of the coxal bone, which has been shown to vary regionally throughout its structure (Besnault et al, 1998 ; Anderson et al, 2008 ; Kim et al, 2009 ; Salo et al, 2012 ; Ma et al, 2015 ). Obtaining accurate cortical thickness measurements from clinical CT images, however, remains problematic due to limitations in resolution and a lack of well-defined boundaries between the cortical and underlying trabecular bone (Prevrhal et al, 1999 ).…”

Multiscale geometric modeling of macromolecules II: Lagrangian representation

“…With a given surface, the surface meshing and volumetric meshing [67, 24] are important tasks as in the continuum mechanical analysis [56, 59, 65]. Many elegant methods have been developed, including such as the probabilistic methods for centroidal Voronoi tessellations [26, 45], the optimal Delaunay triangulation and graph cut based variational surface reconstruction [72], and other surface remeshing enhancement methods and technologies [68, 64, 67, 73, 37], to generate high quality triangle surface meshes that are low-noise, low memory cost, near 60° for majority of element angles and aligned with the physical features.…”

Geometric modeling of subcellular structures, organelles, and multiprotein complexes

“…There are a wide variety of methods that can be used for this purpose. Mesh generation is one of the most important aspects of continuum mechanical analysis [59][60][61][62][63]. Numerous elegant methods, such as the probabilistic methods for centroidal Voronoi tessellations [64,65], the optimal Delaunay triangulation and graph cut-based variational surface reconstruction [66], and other surface remeshing enhancement methods and technologies [41,[67][68][69][70], have been developed for surface reconstruction or surface remeshing during the past two decades.…”