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Modern techniques for medical diagnosis and therapy make considerable use of endoscopes. Unfortunately, the wide-angle characteristic of endoscopes introduce severe aberrations such as chromatic aberration, geometric distortion or comb-structure to the images. The aberrations hinder or at worst prevent the application of fundamental image processing techniques for an appropriate image analysis. In...
The aim of this paper is to introduce effects well known to clinicians -but neglected to date- in the biomechanical modelling of breast malignant tumours. We develop a model of an isolated stellate breast tumour under mammographic compression forces. We study a range of reported mechanical properties, both linear elastic and hyperelastic. We also introduce different volumes of increased density/stiffness...
The paper proposes a novel Extensible Markup Language (XML) based format called ART-ML that aims at supporting the interoperability and the reuse of models of blood flow, mass transport and plaque formation, exported by ARTool. ARTool is a platform for the automatic processing of various image modalities of coronary and carotid arteries. The images and their content are fused to develop morphological...
In this paper we use the modified and integrated version of the balloon model in the analysis of fMRI data. We propose a new state space model realization for this balloon model and represent it with the standard A,B,C and D matrices widely used in system theory. A second order Padé approximation with equal numerator and denominator degree is used for the time delay approximation in the modeling...
The integration of mapping techniques with suitable methods for the characterization and visualization of propagation patterns may enhance the targeting of critical arrhythmic areas, thus optimizing the ablative treatment of atrial arrhythmias. In this study, we tested the feasibility of an innovative approach for the automatic determination of activation and velocity maps from sparse data as provided...
Diffusion MRI allows the obtaining of an approximation of the water displacement's probability density function (PDF) and orientation distribution function (ODF). Examples of techniques used in obtaining these distributions being q-space imaging (QSI), and q-ball imaging (QBI), respectively. Shannon information quantifies the discriminative power of a symbol based on its probability. We quantified...
Only a planar bioluminescence image acquired from an ordinary cooled charge-coupled device (CCD) array every time, how to re-establish the three-dimensional small animal shape and light intensity distribution on the surface has become urgent to be solved as a bottleneck of bioluminescence tomography (BLT) reconstruction. In this paper, a finite element algorithm to solve the Dirichlet type problem...
Electrical impedance tomography (EIT) offers a possibility of realizing of a low cost and safe modality for clinically monitoring patients being treated with mechanical ventilation. However, image reconstruction algorithm employed at different clinical or research settings varies from one to another, which in turn makes interpretation of regional ventilation across institutions difficult. Seeing the...
In this paper, a fully automated method for segmenting Left Ventricle (LV) in echocardiography images is proposed. A new method named active ellipse model is developed to automatically find the best ellipse inside the LV chamber without intervention of any specialist. A modified B-Spline Snake algorithm is used to segment the LV chamber in which the initial contour is formed by the predefined ellipse...
The acetabular cartilage is normally represented as a spherical shape in orthopedic clinic and related researches. The aim of the study was to present a new mathematic representation with better fit to the acetabular cartilage surface and to investigate the role of its shape on the hip joint contact stress. Combined with reverse engineering technique, surface-fitting algorithms and mathematical curve...
The topologically correct and geometrically accurate reconstruction of the cerebral cortex from magnetic resonance (MR) images is an important step in quantitative analysis of the human brain structure, e.g. in cortical thickness measurement studies. Limited resolution of MR images, noise, intensity inhomogeneities, and partial volume effects can all contribute to geometrical inaccuracies and topological...
In this paper, we employ the concept of the Fisher information matrix (FIM) to reformulate and improve on the “Newton's One-Step Error Reconstructor” (NOSER) algorithm. FIM is a systematic approach for incorporating statistical properties of noise, modeling errors and multi-frequency data. The method is discussed in a maximum likelihood estimator (MLE) setting. The ill-posedness of the inverse problem...
This paper proposes a new approach for the selection of a biophysical model describing the haemodynamic response function (HRF) measured in BOLD-fMRI data, based on model falsification techniques. Specifically, the novel method of Multiple Model Set-Valued Observers (MMSVOs) is introduced. The observers consider that the initial state lives in a set, the linear time-varying dynamic system obtained...
Realistic models of the muscle fibers in the myocardium improve the understanding and simulation of the bio-mechanical behavior of the heart. Since Diffusion Tensor Imaging (DTI) allows to visualize the fiber structures in the tissues, this modality can be used to build fiber models. In this paper, we propose an automatic method for the analysis of the helix and transverse angles between the fibers...
Through the combination of intensity and fuzzy edge strength measures, a new partial volume averaging (PVA) quantification technique for FLAIR MRI with white matter lesions (WML) is developed. It is focused on an edge-based approach, which “probes” for PVA voxels via a global estimate for the change in the proportion of tissues α'. This estimate is refined according to a probabilistic threshold, and...
This paper investigates the applicability of multilevel macroscopic models for simulating solid tumor growth in the invasive glioblastoma multiforme (GBM) case. The continuum case approach tumor model based on the diffusion reaction equation is evaluated on a pre-segmented tomographic atlas where all tissue properties are known a priori. The atlas is further registered on a real clinical case where...
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