title: Multi-modal robust inverse-consistent linear registration.
abstract: Registration performance can significantly deteriorate when image regions do not comply with model assumptions. Robust estimation improves registration accuracy by reducing or ignoring the contribution of voxels with large intensity differences, but existing approaches are limited to monomodal registration. In this work, we propose a robust and inverse-consistent technique for cross-modal, affine image registration. The algorithm is derived from a contextual framework of image registration. The key idea is to use a modality invariant representation of images based on local entropy estimation, and to incorporate a heteroskedastic noise model. This noise model allows us to draw the analogy to iteratively reweighted least squares estimation and to leverage existing weighting functions to account for differences in local information content in multimodal registration. Furthermore, we use the nonparametric windows density estimator to reliably calculate entropy of small image patches. Finally, we derive the Gauss-Newton update and show that it is equivalent to the efficient second-order minimization for the fully symmetric registration approach. We illustrate excellent performance of the proposed methods on datasets containing outliers for alignment of brain tumor, full head, and histology images.
authors.affiliation: Department of Electrical Engineering and Computer Science, Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, 02114.
authors.forename: Christian
authors.initials: C
authors.lastname: Wachinger
authors.forename: Polina
authors.initials: P
authors.lastname: Golland
authors.forename: Caroline
authors.initials: C
authors.lastname: Magnain
authors.forename: Bruce
authors.initials: B
authors.lastname: Fischl
authors.forename: Martin
authors.initials: M
authors.lastname: Reuter
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology / Q000473:pathology; D001932:Brain Neoplasms / Q000473:pathology; D003198:Computer Simulation; D003287:Contrast Media; D066264:Datasets as Topic; D019277:Entropy; D005682:Gadolinium; D006257:Head / Q000033:anatomy & histology / Q000473:pathology; D006652:Histological Techniques / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016018:Least-Squares Analysis; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D008959:Models, Neurological; D064847:Multimodal Imaging / Q000379:methods; D061848:Optical Imaging / Q000379:methods*; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: computer-assisted image analysis; histology; magnetic resonance imaging; optical coherence tomography; rigid and affine image alignment; statistical model