This paper proposes a new model to simulate the growth of glioblastomas multiforma GBM, the most aggressive glial tumors. This model relies upon an anatomical atlas including white fibers diffusion tensor information and the delineation of cerebral structures having a distinct response to the tumor aggression. It simulates both the...
This paper introduces a fast non-rigid registration method for aligning pre-operative 1.5 T MR Images to intra-operative 0.5 T MR Images for guidance in prostate biopsy. After the acquisition of both pre-operative 1.5 T and intra-operative 0.5 T, an intensity correction method is applied to the pre-operative images to reduce...
This paper presents a composite method for landmark-guided surface matching and volumetric non-rigid registration, with an application to prostate biopsy. The two-step method, based primarily on finite element and thin-plate spline techniques, consists of a boundary matching process, followed by a volumetric warping step. In practice, the boundary matching method...
This paper presents a new method for detecting the interface, or edge, structure present in diffusion MRI. Interface detection is an important first step for applications including segmentation and registration. Additionally, due to the higher dimensionality of tensor data, humans are visually unable to detect edges as easily as in...
Diffusion tensor MRI (DT-MRI) is an image modality that is gaining clinical importance. After some preliminaries that describe the fundamentals of this imaging modality, they present a new technique to interpolate the diffusion tensor field, preserving boundaries and the constraint of positive-semi definiteness. Their approach is based on the use...
Radiofrequency ablation is being used increasingly in the treatment of liver tumors, and the detection of local recurrences on follow-up imaging is an important and occasionally challenging task. When the tumor is not associated with nodular enhancement, recurrence detection only relies on a precise identification of shape changes in the...
This paper is based on an experiment for testing the positioning repeatability of MR-compatible manipulator with a CCD laser micrometer inside MRI. To evaluate the performance of MR-compatible manipulator inside MRI, the measuring system must be confirmed to work correctly inside MRI in advance. Therefore, the measuring system was tested...
This paper proposes an Expectation-Maximization approach to separate a shape database into different shape classes, while simultaneously estimating the shape contours that best exemplify each of the different shape classes. They begin their formulation by employing the level set function as the shape descriptor. Next, for each shape class they...
During cryotherapy, it is extremely useful for the interventionalists to have available intra-operatively a 3D iceball visualization, to ensure the effectiveness and safety of the procedure. Additionally, it is highly beneficial to provide the interventionalists with a best estimate of how the iceball will grow in the future, and an...
This paper introduces a new, efficient approach for modelling the deformation of organs following surgical cuts, retractions, and resections. It uses the extended finite element method XFEM, recently developed in "fracture mechanics" for dealing with cracks in mechanical parts. XFEM eliminates the computationally-expensive remeshing that would be required if the...
In this paper, they show that standard activation statistics, such as F-statistics, are derived from the log-likelihood ratio of a subset hypothesis test under classical, linear models of the BOLD signal. Consequently, the same exact MAP activity detection mechanism can be used with such General Linear Models GLMs; thereby controlling...
This paper studies the determinants of sensitivity to the promotional activities of temporary price reductions, displays, and feature advertisements. Both the theoretical and empirical literatures on price promotions suggest that retailer competition and the demographic composition of the shopping population should be linked to response to temporary price cuts. However,...
This paper presents a filtering technique for regularizing tensor fields. It uses a nonlinear filtering technique termed normalized convolution, a general method for filtering missing and uncertain data. In the present work we extend the signal certainty function to depend on locally derived certainty information in addition to the priory...
In this paper a model of start-up finance is set up under double moral hazard. Entrepreneurs lack own resources and business experience to develop their ideas. Venture capitalists can provide start-up finance and commercial support. The effort put forth by either agent contributes to the firm's success, but is not...
This paper describes a new method for visualizing tensor fields using a textured mapped volume rendering approach, tensor-splatting. It uses an image order method to calculate the 2D Gaussian splats or footprints of the projected 3D Gaussians at an arbitrary number of standard deviations from the centroid. These footprints are...
This paper proposes a novel approach to landmark-based medical image registration based on the geostatical method of Kriging prediction. This method exploits the spatial statistical relation between two images, as estimated using general purpose registration algorithms, in order to construct an optimum predictor of the displacement field. High accuracy is...
DT-MRI fields measure the self-diffusion of water in biological tissue and, hence, tensors from these fields must be symmetric positive definite PSD. However, due to a number of reasons this is not true for real data. Furthermore, it would be desirable to maintain that condition when tensor data are filtered....
This paper proposes a novel non-Gaussian MRF for regularization of tensor fields for fiber tract enhancement. Two entities are considered in the model, namely, the linear component of the tensor, i.e., how much line-like the tensor is and the angle of the eigenvector associated to the largest eigenvalue. A novel,...
This paper investigates new approaches to quantifying the white matter connectivity in the brain using Diffusion Tensor Magnetic Resonance Imaging data. Their first approach finds a steady-state concentration/ heat distribution using the three-dimensional tensor field as diffusion/ conductivity tensors. Their second approach casts the problem in a Riemannian framework, deriving...
MRI tissue tagging of the heart produces noninvasive markers within the muscle wall that can be used to measure motion and deformation. However, the widespread use of tissue tagging has been limited by time-consuming image post-processing. This paper outlines a method for automatic 3D tracking of LV motion from 2D...
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