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64
Fast parametric elastic image registration
 IEEE Transactions on Image Processing
, 2003
"... Abstract—We present an algorithm for fast elastic multidimensional intensitybased image registration with a parametric model of the deformation. It is fully automatic in its default mode of operation. In the case of hard realworld problems, it is capable of accepting expert hints in the form of so ..."
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Cited by 102 (8 self)
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Abstract—We present an algorithm for fast elastic multidimensional intensitybased image registration with a parametric model of the deformation. It is fully automatic in its default mode of operation. In the case of hard realworld problems, it is capable of accepting expert hints in the form of soft landmark constraints. Much fewer landmarks are needed and the results are far superior compared to pure landmark registration. Particular attention has been paid to the factors influencing the speed of this algorithm. The Bspline deformation model is shown to be computationally more efficient than other alternatives. The algorithm has been successfully used for several twodimensional (2D) and threedimensional (3D) registration tasks in the medical domain, involving MRI, SPECT, CT, and ultrasound image modalities. We also present experiments in a controlled environment, permitting an exact evaluation of the registration accuracy. Test deformations are generated automatically using a random hierarchical fractional waveletbased generator. Index Terms—Elastic registration, image registration, landmarks, splines. I.
Landmarkbased elastic registration using approximating thinplate splines
 IEEE Trans. Med. Imag
, 2001
"... Abstract—We consider elastic image registration based on a set of corresponding anatomical point landmarks and approximating thinplate splines. This approach is an extension of the original interpolating thinplate spline approach and allows to take into account landmark localization errors. The ..."
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Cited by 69 (0 self)
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Abstract—We consider elastic image registration based on a set of corresponding anatomical point landmarks and approximating thinplate splines. This approach is an extension of the original interpolating thinplate spline approach and allows to take into account landmark localization errors. The extension is important for clinical applications since landmark extraction is always prone to error. Our approach is based on a minimizing functional and can cope with isotropic as well as anisotropic landmark errors. In particular, in the latter case it is possible to include different types of landmarks, e.g., unique point landmarks as well as arbitrary edge points. Also, the scheme is general with respect to the image dimension and the order of smoothness of the underlying functional. Optimal affine transformations as well as interpolating thinplate splines are special cases of this scheme. To localize landmarks we use a semiautomatic approach which is based on threedimensional (3D) differential operators. Experimental results are presented for two–dimensional as well as 3D tomographic images of the human brain. Index Terms—Anatomical landmarks, image matching, segmentation, splines. I.
A review of geometric transformations for nonrigid body registration
 IEEE TRANSACTIONS ON MEDICAL IMAGING
, 2007
"... ..."
K.: Threedimensional linear and nonlinear transformations: An integration of light microscopical and mri datas
 Human Brain Mapping
, 1998
"... r r Abstract: The registration of image volumes derived from different imaging modalities such as MRI, PET, SPECT, and CT has been described in numerous studies in which functional and morphological data are combined on the basis of macrostructural information. However, the exact topography of archi ..."
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Cited by 59 (12 self)
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r r Abstract: The registration of image volumes derived from different imaging modalities such as MRI, PET, SPECT, and CT has been described in numerous studies in which functional and morphological data are combined on the basis of macrostructural information. However, the exact topography of architectural details is defined by microstructural information derived from histological sections. Therefore, a technique is developed for integrating micro and macrostructural information based on 1) a threedimensional reconstruction of the histological volume which accounts for linear and nonlinear histological deformations, and 2) a twostep procedure which transforms these volumes to a reference coordinate system. The twostep procedure uses an extended principal axes transformation (PAT) generalized to affine transformations and a fast, automated fullmultigrid method (FMG) for determining highdimensional threedimensional nonlinear deformations in order to account for differences in the morphology of individuals. With this technique, it is possible to define upwards of 1,000 times the resolution of,1 mm in MRI, making possible the identification of geometric and texture features of microscopically defined brain structures.
Radial Basis Functions with Compact Support for Elastic Registration of Medical Images
 IVC
, 1999
"... . Common elastic registration schemes based on landmarks and using radial basis functions (RBFs) such as thinplate splines or multiquadrics are global. Here, we introduce radial basis functions with compact support for elastic registration of medical images. With these basis functions the inuen ..."
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Cited by 47 (0 self)
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. Common elastic registration schemes based on landmarks and using radial basis functions (RBFs) such as thinplate splines or multiquadrics are global. Here, we introduce radial basis functions with compact support for elastic registration of medical images. With these basis functions the inuence of a landmark on the registration result is limited to a circle in 2D or, respectively, to a sphere in 3D. Therefore, the registration can be locally constrained which especially allows to deal with rather local changes in medical images due to, e.g., tumor resection. An important property of the used RBFs is that they are positive denite. Thus, the solvability of the resulting system of equations is always guaranteed. We give the theoretical background of the basis functions with compact support and compare them with other basis functions w.r.t. locality, solvability, and eciency. We demonstrate the applicability of our approach for synthetic as well as for 2D and 3D tomograph...
Unwarping of Unidirectionally Distorted EPI Images
, 2000
"... Echoplanar imaging (EPI) is a fast nuclear magnetic resonance imaging method. Unfortunately, local magnetic field inhomogeneities induced mainly by the subject 's presence cause significant geometrical distortion, predominantly along the phaseencoding direction, which must be undone to allow ..."
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Cited by 40 (7 self)
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Echoplanar imaging (EPI) is a fast nuclear magnetic resonance imaging method. Unfortunately, local magnetic field inhomogeneities induced mainly by the subject 's presence cause significant geometrical distortion, predominantly along the phaseencoding direction, which must be undone to allow for meaningful further processing. So far, this aspect has been too often neglected.
NonRigid RangeScan Alignment Using ThinPlate Splines
 In Proc. 3D Data Processing, Visualization, and Transmission
, 2004
"... We present a nonrigid alignment algorithm for aligning highresolution range data in the presence of lowfrequency deformations, such as those caused by scanner calibration error. Traditional iterative closest points (ICP) algorithms, which rely on rigidbody alignment, fail in these cases because t ..."
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Cited by 33 (3 self)
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We present a nonrigid alignment algorithm for aligning highresolution range data in the presence of lowfrequency deformations, such as those caused by scanner calibration error. Traditional iterative closest points (ICP) algorithms, which rely on rigidbody alignment, fail in these cases because the error appears as a nonrigid warp in the data. Our algorithm combines the robustness and efficiency of ICP with the expressiveness of thinplate splines to align highresolution scanned data accurately, such as scans from the Digital Michelangelo Project [14]. This application is distinguished from previous uses of the thinplate spline by the fact that the resolution and size of warping are several orders of magnitude smaller than the extent of the mesh, thus requiring especially precise feature correspondence. 1.
Approximating ThinPlate Splines for Elastic Registration: Integration of Landmark Errors and Orientation Attributes
 In Proc. of IPMI'99, volume 1613 of LNCS
, 1999
"... . We introduce an approach to elastic registration of tomographic images based on thinplate splines. Central to this scheme is a welldened minimizing functional for which the solution can be stated analytically. In this work, we consider the integration of anisotropic landmark errors as well a ..."
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Cited by 20 (1 self)
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. We introduce an approach to elastic registration of tomographic images based on thinplate splines. Central to this scheme is a welldened minimizing functional for which the solution can be stated analytically. In this work, we consider the integration of anisotropic landmark errors as well as additional attributes at landmarks. As attributes we use orientations at landmarks and we incorporate the corresponding constraints through scalar products. With our approximation scheme it is thus possible to integrate statistical as well as geometric information as additional knowledge in elastic image registration. On the basis of synthetic as well as real tomographic images we show that this additional knowledge can signicantly improve the registration result. In particular, we demonstrate that our scheme incorporating orientation attributes can preserve the shape of rigid structures (such as bone) embedded in an otherwise elastic material. This is achieved without selecting...
Investigation of Approaches for the Localization of Anatomical Landmarks in 3D Medical Images
, 1997
"... this paper we present an approach to localize semiautomatically landmarks characterized by extremal isocontour curvature. The semiautomatic approach implies that a rough estimate of the landmark position centered at a volumeofinterest is interactively provided by the user as an input. The algori ..."
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Cited by 18 (10 self)
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this paper we present an approach to localize semiautomatically landmarks characterized by extremal isocontour curvature. The semiautomatic approach implies that a rough estimate of the landmark position centered at a volumeofinterest is interactively provided by the user as an input. The algorithm then refines this position [10]. Monga and Benayoun [4] presented an approach to compute locally the curvature characteristics of isosurfaces. The gradient direction is used to define locally the tangent plane of the isosurface. Then a local parametrization is defined by setting up two arbitrary orthogonal vectors within this tangent plane. Given this parametrization they show how the principal curvatures of the isosurface and the associated principal directions can be computed. Additionally, they derive an extremality criterion based on the spatial derivative of the principal curvature in direction of the corresponding principal direction. Application of this extremality criterion in maximum curvature direction yields a 1D subset of points on the isosurface which they call ridge (or crest) lines. Thirion [6] proposed an algorithm to extract automatically isocontour curvature extrema, which he denoted extremal points, from 3D images and which then serve as input for a rigid registration algorithm. His algorithm basically uses the extremality criterion of Monga and Benayoun [4] in both principal curvature directions.
Elastic Registration of Medical Images Using Radial Basis Functions with Compact Support
, 1999
"... We introduce radial basis functions with compact support for elastic registration of medical images. With these basis functions the influence of a landmark on the registration result is limited to a circle in 2D and, respectively, to a sphere in 3D. Therefore, the registration can be locally constra ..."
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Cited by 18 (1 self)
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We introduce radial basis functions with compact support for elastic registration of medical images. With these basis functions the influence of a landmark on the registration result is limited to a circle in 2D and, respectively, to a sphere in 3D. Therefore, the registration can be locally constrained which especially allows to deal with rather local changes in medical images due to, e.g., tumor resection. An important property of the used RBFs is that they are positive definite. Thus, the solvability of the resulting system of equations is always guaranteed. We demonstrate our approach for synthetic as well as for 2D and 3D tomographic images. 1. Introduction Registration is an important technique in medical image analysis. Rigid and affine registration methods can only cope with global differences, for example, translation, rotation, and scaling. In many cases, however, elastic or nonrigid methods are required to cope with local differences between the images. Such differences ar...