title: A Log-Euclidean polyaffine registration for articulated structures in medical images.
abstract: In this paper we generalize the Log-Euclidean polyaffine registration framework of Arsigny et al. to deal with articulated structures. This framework has very useful properties as it guarantees the invertibility of smooth geometric transformations. In articulated registration a skeleton model is defined for rigid structures such as bones. The final transformation is affine for the bones and elastic for other tissues in the image. We extend the Arsigny el al.'s method to deal with locally-affine registration of pairs of wires. This enables the possibility of using this registration framework to deal with articulated structures. In this context, the design of the weighting functions, which merge the affine transformations defined for each pair of wires, has a great impact not only on the final result of the registration algorithm, but also on the invertibility of the global elastic transformation. Several experiments, using both synthetic images and hand radiographs, are also presented.
authors.affiliation: Laboratory of Image Processing, ETSI Telecomunicaciones, University of Valladolid, Campus Miguel Delibes s/n, 47011 Valladolid, Spain. migmar@tel.uva.es
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Martín-Fernández
authors.forename: Marcos
authors.initials: M
authors.lastname: Martín-Fernández
authors.forename: Carlos
authors.initials: C
authors.lastname: Alberola-López
mesh_terms: D000465:Algorithms; D001175:Arthrography / Q000379:methods*; D001185:Artificial Intelligence; D005384:Finger Joint / Q000000981:diagnostic imaging*; D006801:Humans; D010363:Pattern Recognition, Automated / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique