ASSESSMENT OF MASS PROPERTIES OF HUMAN HEAD USING VARIOUS 3-DIMENSIONAL IMAGING MODALITIES

Better methods are needed to analyse personal protective devices, such as helmets or facemasks, before they are used in practice. Software t ools to quantify three-dimensional craniofacial mass properties are de veloped to improve our understanding of craniofacial impact biomechani cs, supplement existing knowledge of osseous structure and provide a c omprehensive description of human head morphology. The application of state-of-the-art imaging systems, solid modelling and other software t ools are studied to determine the associated errors in mass property e stimation by spiral computed tomography, three-dimensional magnetic re sonance and optical surface scanning using phantoms and cadaver head s tudies. Volume, centre of gravity and principal moments of inertia are determined from solid mathematical models for each scanning modality. Landmark-based registration is used to register scans of the same obj ect obtained from the three imaging modalities to a common reference c o-ordinate system. Physically and analytically determined mass propert ies are used as the standard for truth. Although this comparative stud y does not lend itself to;statistical analysis owing to the small samp le size, results indicate that any of the three imaging modalities can be used to predict mass properties within the uncertainty of existing methods. Applying these techniques in vivo is practical and feasible.