Search results for "Image Interpretation"
showing 10 items of 201 documents
Filter performance parameters for vectorial high-aperture wave fields.
2008
Performance parameters have been presented that can be used to compare the focusing performance of different optical systems, including the effect of pupil filters. These were originally given for the paraxial case and recently extended to the high-aperture scalar regime. We generalize these parameters to the full vectorial case for an aplanatic optical system illuminated by a plane-polarized wave. The behavior of different optical systems is compared.
Simulation of skin reflectance images using 3D tissue modeling and multispectral Monte Carlo light propagation.
2008
In this work we propose a method to simulate the expected, i.e. seen by a camera, multispectral reflectance images of a large skin surface area by combining Monte Carlo light propagation model and realistic tissue modeling based on three dimensional data acquisition of human body areas. In particular, we aim to simulate more accurately light transport in biological tissue by taking into account the geometrical topography of the skin surface, the structure and optical properties of the skin layers, and the subcutaneous veins in presence. We describe our computation method in detail and present simulated reflectance images results.
Unsupervised recognition of retinal vascular junction points.
2014
Landmark points in retinal images can be used to create a graph representation to understand and to diagnose not only different pathologies of the eye, but also a variety of more general diseases. Aim of this paper is the description of a non-supervised methodology to distinguish between bifurcations and crossings of the retinal vessels, which can be used in differentiating between arteries and veins. A thinned representation of the binarized image, is used to identify pixels with three or more neighbors. Junction points are classified into bifurcations or crossovers according to their geometrical and topological properties. The proposed approach is successfully compared with the state-of-t…
Influence of pixel size on quantification of airway wall thickness in computed tomography.
2009
Objectives: The purpose of this study was to determine the point where a further decrease in voxel size does not result in better automatic quantification of the bronchial wall thickness by using 2 different assessment techniques. Materials and Methods: The results from the commonly used full-width-at-half-maximum (FWHM) principle and a new technique (integral-based method [IBM]) were compared for thin-section multidetector computed tomography (MDCT) data sets from an airway phantom containing 10 different tubular airway phantoms and in a human subsegmental bronchus in vivo. Correlation with the actual wall thickness and comparison of the wall thicknesses assessed for different voxel sizes …
Superresolved imaging of remote moving targets.
2006
We present a superresolving approach that allows one to exceed the diffraction limit and recover highly resolved contours of moving targets from a sequence of low-resolution images. The presented approach is suitable for remote sensing applications. The resolution decoding algorithm that is used to recover the high-resolution features of the target can be run partially via optical means and that way can be used to reduce the required computational complexity.
Computational analysis to predict false-lumen perfusion and outcome of type B aortic dissection.
2014
We have attempted to identify potential predictors foracute and late aortic events starting from admission computed tomographic images.
Mitral valve annuloplasty and papillary muscle relocation oriented by 3-dimensional transesophageal echocardiography for severe functional mitral reg…
2012
Objective The study of the mitral valve apparatus and its modifications during functional mitral regurgitation (FMR) is better revealed by 3-dimensional (3D) transesophageal echocardiography (TOE). To plan mitral valve repair by annuloplasty and papillary muscle (PPM) relocation, we proposed a valve repair procedure oriented by the new main features obtained by real-time 3D TOE reconstruction of the mitral valve apparatus. Methods Since January 2008, 25 patients with severe FMR before mitral valve repair were examined. Mean coaptation depth and mean tenting area were 1.3 ± 0.2 cm and 3.2 ± 0.5 cm 2 , respectively. Intraoperative 2D and 3D TOE were performed, followed by a 3D offline reconst…
Regularization operators for natural images based on nonlinear perception models.
2006
Image restoration requires some a priori knowledge of the solution. Some of the conventional regularization techniques are based on the estimation of the power spectrum density. Simple statistical models for spectral estimation just take into account second-order relations between the pixels of the image. However, natural images exhibit additional features, such as particular relationships between local Fourier or wavelet transform coefficients. Biological visual systems have evolved to capture these relations. We propose the use of this biological behavior to build regularization operators as an alternative to simple statistical models. The results suggest that if the penalty operator take…
[Current developments and perspectives on the diagnosis and treatment of urinary incontinence and genital prolapse in women].
2012
As a key area of gynaecology, urogynaecology has undergone impressive changes in the past few years. Together with the high prevalence of functional pelvic floor disorders, modern anaesthesia procedures and the introduction of new, innovative minimally invasive operation techniques have led to a dramatic increase in the number of operations for incontinence and prolapses. The increasingly subtle diagnostic options, such as, e. g., 2D and 3D sonography of the pelvic floor provide unambiguous findings and facilitate decision making. Tension-free vaginal slings in retro-pubic, trans-obturator or single-incision techniques show a high success rate with few complications and have almost complete…
Microaneurysm detection with radon transform-based classification on retina images.
2012
The creation of an automatic diabetic retinopathy screening system using retina cameras is currently receiving considerable interest in the medical imaging community. The detection of microaneurysms is a key element in this effort. In this work, we propose a new microaneurysms segmentation technique based on a novel application of the radon transform, which is able to identify these lesions without any previous knowledge of the retina morphological features and with minimal image preprocessing. The algorithm has been evaluated on the Retinopathy Online Challenge public dataset, and its performance compares with the best current techniques. The performance is particularly good at low false p…