Statistical Shape Modeling for Craniosynostosis Planning

Abstract

As research on the correction of underlying disorders on the cellular level is still being carried on (Flores-Sarnat 2002), patients with premature craniosynosthosis depend on surgical intervention for improving their appearance and preventing or reducing functional impairment.

The most commonly used surgical procedure consists of bone fragmentation, deformation (reshaping) and repositioning based on standards developed by Paul Tessier (1967), Daniel Marchac and Dominique Renier.

A major problem is the evaluation of the aesthetic results of reshaping the cranial vault in small children as the literature does not provide sufficient criteria for assessing skull shape.

In order to establish such criteria we propose to perform statistical analysis of cranial shapes of healthy subjects. This information can then be used to map pathological shapes onto the statistical ensemble of the healthy shapes. The result provides a patient-specific basis for the remodeling process.

In this work we will describe a method for performing 3d comparison of different shapes of the part of the cranium that is relevant in such surgical procedures. It is based on consistent parametrization of different meshes onto a common base domain (Lamecker et al., 2002, 2003). The resulting correspondence mappings allow for statistical analysis. We use principal component analysis to extract a mean shape plus the most typical shape variations in terms of the variance contained in the training set.

We will present preliminary results obtained from a training set of about 20 different shapes.

Hans Lamecker

Director, Software Development

Advancing 3D analysis, planning, design and manufacturing using innovative computational methods and tools