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We propose a novel framework for longitudinal registration which can handle large intra-subject anatomical variations. The framework exploits freely available spatio-temporal atlases, which can aid the longitudinal registration process as it provides prior information about the missing anatomical evolution between two scans taken over large time-interval. The spatio-temporal atlas is used to develop...
In this paper, a new registration method that based on shape information and gray information has been introduced to the procedure of CT-MRI registration. In the first, the frames of the two images to be registered were explained by the principle of mechanics decomposition, then we coarsely registered the two images by their frames and as a result the error of the registration was limited in a small...
Real-time magnetic resonance imaging is a promising tool for image-guided interventions. For applications such as thermotherapy on moving organs, a precise image-based compensation of motion is required in real time to allow quantitative analysis, retrocontrol of the interventional device, or determination of the therapy endpoint. Reduced field-of-view imaging represents a promising way to improve...
A spin-off of the Extended Gaussian Image [1] (EGI) registration technique to volumetric datasets is presented. This spin-off technique directly allows recovery of the rotation (and indirectly may allow recovery of the translation) transformations that aligns one volumetric dataset to another. An extension of the basic EGI's orientation histogram to volumetric datasets is also described. Using this...
A method of non-rigid image registration was developed and evaluated for the purpose of quantifying myocardial displacement and strain from cine MRI using DENSE MRI as the reference standard. The objective of this paper was to study the potential use of cine MRI with image registration, as a means of measuring strain. The local displacement of the left ventricle was modelled by free-form deformations...
In this work, we present a scheme for the registration of digitally reconstructed whole mount histology (WMH) to pre-operative in vivo multiprotocol prostate MR imagery (T2w and DCE) using spatially weighted mutual information (SWMI). Spatial alignment of ex vivo histological sections to pre-operative in vivo MRI for prostate cancer (CaP) patients undergoing radical prostatectomy is a necessary first...
This paper presents the evaluation of the accuracy of an elastic registration algorithm, based on the particle filter and an optical flow process. The algorithm is applied in brain CT and MRI simulated image datasets, and MRI images from a real clinical radiotherapy case. To validate registration accuracy, standard indices for registration accuracy assessment were calculated: the dice similarity coefficient...
This paper presents an effective registration method between two geophysical images from different modalities, namely magnetic and electrical, in order to increase the information obtained from the two original images independently. In order to achieve the registration, random local transformations were applied in 5 × 5 randomly chosen windows of the sensed image while the mutual information was used...
In the last few decades, image registration (IR) has been established as a very active research area in computer vision. Over the years, it has been applied to a broad range of real-world problems ranging from remote sensing to medical imaging, artificial vision, and computer-aided design. IR has been usually tackled by iterative approaches considering numerical optimization methods which are likely...
This paper presents how using a correspondence-based interpolation scheme for 3D image registration improves the registration accuracy. The interpolator takes into account correspondences across slices, which is an advantage, particularly when the volume has thick slices, and where anatomies lie non-parallel to the slice direction. We use our previously presented approach for correspondence-based...
Clinical diagnosis and quantification of liver disease have been improved through the development of techniques using contrast-enhanced liver MRI sequences. To qualitatively or quantitatively analyze such image sequences, one first needs to correct for rigid and non-rigid motion of the liver. For motion correction of the liver, we have employed bi-directional local correlation coefficient Demons,...
In this paper, we develop a new deformable registration algorithm for images with pathology-induced topological changes. In this algorithm, 3D images are embedded as 4D surfaces in a Riemannian space and the registration is conducted as a surface evolution process. Our algorithm differs from existing methods in the sense that it takes an a-priori estimation of areas with topological change as an additional...
We present a method for the registration of whole-mount digital histology images to ex vivo MR images of the prostate that relaxes the requirement for control over specimen slicing orientation. The approach uses extrinsic fiducials visible on histology and MRI, as well as block MR images of tissue slices after coarse sectioning, to support a two-stage registration approach: (1) registration of digital...
Magnetic resonance images of the spinal cord play an important role in studying neurological diseases, particularly multiple sclerosis, where spinal cord atrophy can provide a measure of disease progression and disability. Current practices involve segmenting the spinal cord manually, which can be an inconsistent and time-consuming process. We present an automatic segmentation method for the spinal...
Despite reduction in imaging times through improved hardware and rapid acquisition schemes, motion artifacts can compromise image quality in magnetic resonance imaging (MRI). This is especially true for 3D imaging, where scan durations are prolonged and the assumptions of most state-of-the-art 2D rigid body motion compensation techniques break down. This paper introduces a novel motion correction...
Preterm birth is associated with abnormal brain development and long-term neurodevelopmental impairment. Quantitative magnetic resonance (MR) studies of preterm brain injury have focused on morphological features such as shape and volume and on measures of tissue microstructure obtained from diffusion tensor imaging. In this work, we focus on longitudinal changes in signal intensity, which can offer...
A simple, computationally inexpensive, algorithm for performing registration of abdominal dynamic contrast-enhanced (DCE) MRI data is presented. It utilizes an intensity correction term in conjunction with a so-called floating reference image scheme to reduce the effects of contrast agent related intensity changes on registration performance. Using an abdominal DCE-MRI dataset with simulated motion,...
Registration of pre- to intra-procedural prostate images needs to handle the large changes in position and shape of the prostate caused by varying rectal filling and patient positioning. We describe a probabilistic method for non-rigid registration of prostate images which can quantify the most probable deformation as well as the uncertainty of the estimated deformation. The method is based on a biomechanical...
Cardiac magnetic resonance imaging has proved its effectiveness to determine the patient-specific myocardial motion/functional information via the cine imaging and to detect myocardial infarction in the delayed enhanced MRI (DE-MRI). Standard cardiac MR protocols usually acquire these two sets of images across multiple acquisitions with varying imaging slice geometry, pixel spacing and different breath-holdings,...
Investigating multi-feature information-theoretic image registration, we introduce consistent and asymptotically unbiased kth-nearest neighbor (kNN) estimators of mutual information (MI), normalized MI and exclusive information applicable to high-dimensional random variables, and derive under closed-form their gradient flows over finite- and infinite-dimensional transform spaces. Using these results,...
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