title: A symmetry-based method for the determination of vertebral rotation in 3D.
abstract: In the past, a number of methods were proposed for quantitative assessment of vertebral rotation from three-dimensional (3D) images. However, these methods were based on manual identification of distinctive anatomical landmarks, required manual determination of cross-sections from 3D images, and measured only axial vertebral rotation instead of the rotation in 3D. In this paper, we propose an automated method for quantitative assessment of vertebral rotation in 3D that is based on finding the planes of vertebral symmetry by matching image intensity gradients on both sides of each plane. The method was evaluated on 28 images of normal and pathological vertebrae, obtained by computed tomography (CT) and magnetic resonance (MR). For each vertebra, final angle displacements of 200 initial angle displacements, uniformly distributed within 30 degrees from manually obtained reference angles, were obtained. The results show that by the proposed method, vertebral rotation can be successfully estimated in 3D with an average accuracy of 1.0 degrees and precision of 0.5 degrees.
authors.affiliation: University of Ljubljana, Faculty of Electrical Engineering, Slovenia. tomaz.vrtovec@fe.uni-lj.si
authors.forename: Tomaz
authors.initials: T
authors.lastname: Vrtovec
authors.forename: Franjo
authors.initials: F
authors.lastname: Pernus
authors.forename: Bostjan
authors.initials: B
authors.lastname: Likar
mesh_terms: D000465:Algorithms; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity; D013131:Spine / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*