title: Real-scale 3D models of the scoliotic spine from biplanar radiography without calibration objects.
abstract: This paper presents a new method for modelling the spines of subjects and making accurate 3D measurements using standard radiologic systems without requiring calibration objects. The method makes use of the focal distance and statistical models for estimating the geometrical parameters of the system. A dataset of 32 subjects was used to assess this method. The results show small errors for the main clinical indices, such as an RMS error of 0.49° for the Cobb angle, 0.50° for kyphosis, 0.38° for lordosis, and 2.62mm for the spinal length. This method is the first to achieve this level of accuracy without requiring the use of calibration objects when acquiring radiographs. We conclude that the proposed method allows for the evaluation of scoliosis with a much simpler setup than currently available methods.
authors.affiliation: Instituto de Telecomunicações, Departamento de Engenharia Electrotécnica e de Computadores, Faculdade de Engenharia, Universidade do Porto, Porto, Portugal. Electronic address: daniel.moura@fe.up.pt.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Moura
authors.affiliation: Departamento de Engenharia Informática, Faculdade de Engenharia, Universidade do Porto, Porto, Portugal; Laboratório de Intelegência Artificial e Ciência dos Computadores, Porto, Portugal.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Barbosa
mesh_terms: D000465:Algorithms; D002138:Calibration; D003198:Computer Simulation; D003199:Computer Systems; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008953:Models, Anatomic; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012600:Scoliosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: 3D Reconstruction; Calibration; Radiography; Statistical modelling; Stereoscopy; Vertebra localisation