Image-Guided Analysis of Shoulder Pathologies: Modelling the 3D Deformation of the Subacromial Space during Arm Flexion and Abduction

Abstract

Abstract. This paper describes a simple, yet efficient method for modelling complex musculo-skeletal structures in motion. The proposed approach contains three main modules: segmentation, 3D reconstruction, and feature extraction. The segmentation module integrates region and edge information in a coherent manner. The 3D reconstruction technique is based on morphological morphing between adjacent slices and on contour-based extrapolation of extreme slices. Model validation is a rather challenging task, since no direct access is possible to in vivo human bony structures of the shoulder complex. We implement an internal validation approach, based on comparing the three models built for the same human shoulder. Finally, two descriptors of the subacromial space deformation during arm motion are computed. Their reliability is assessed using statistics of the healthy human shoulder.