Blog
About

  • Record: found
  • Abstract: not found
  • Article: not found

Non-Rigid Event-by-Event Continuous Respiratory Motion Compensated List-Mode Reconstruction for PET

Read this article at

ScienceOpenPublisher
Bookmark
      There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

      Related collections

      Most cited references 42

      • Record: found
      • Abstract: found
      • Article: not found

      Nonrigid registration using free-form deformations: application to breast MR images.

      In this paper we present a new approach for the nonrigid registration of contrast-enhanced breast MRI. A hierarchical transformation model of the motion of the breast has been developed. The global motion of the breast is modeled by an affine transformation while the local breast motion is described by a free-form deformation (FFD) based on B-splines. Normalized mutual information is used as a voxel-based similarity measure which is insensitive to intensity changes as a result of the contrast enhancement. Registration is achieved by minimizing a cost function, which represents a combination of the cost associated with the smoothness of the transformation and the cost associated with the image similarity. The algorithm has been applied to the fully automated registration of three-dimensional (3-D) breast MRI in volunteers and patients. In particular, we have compared the results of the proposed nonrigid registration algorithm to those obtained using rigid and affine registration techniques. The results clearly indicate that the nonrigid registration algorithm is much better able to recover the motion and deformation of the breast than rigid or affine registration algorithms.
        Bookmark
        • Record: found
        • Abstract: not found
        • Article: not found

        An overlap invariant entropy measure of 3D medical image alignment

          Bookmark
          • Record: found
          • Abstract: found
          • Article: not found

          Image similarity and tissue overlaps as surrogates for image registration accuracy: widely used but unreliable.

          The accuracy of nonrigid image registrations is commonly approximated using surrogate measures such as tissue label overlap scores, image similarity, image difference, or transformation inverse consistency error. This paper provides experimental evidence that these measures, even when used in combination, cannot distinguish accurate from inaccurate registrations. To this end, we introduce a "registration" algorithm that generates highly inaccurate image transformations, yet performs extremely well in terms of the surrogate measures. Of the tested criteria, only overlap scores of localized anatomical regions reliably distinguish reasonable from inaccurate registrations, whereas image similarity and tissue overlap do not. We conclude that tissue overlap and image similarity, whether used alone or together, do not provide valid evidence for accurate registrations and should thus not be reported or accepted as such.
            Bookmark

            Author and article information

            Journal
            IEEE Transactions on Medical Imaging
            IEEE Trans. Med. Imaging
            Institute of Electrical and Electronics Engineers (IEEE)
            0278-0062
            1558-254X
            February 2018
            February 2018
            : 37
            : 2
            : 504-515
            10.1109/TMI.2017.2761756
            © 2018
            Product

            Comments

            Comment on this article