The present study characterizes the mechanical properties of polyvinyl alcohol (PVA) cryogel in order to show its utility for intravascular elastography. PVA becomes harder with an increasing number freeze-thaw cycles, and Young's modulus Poisson's ratio are measured seven samples. Mechanical tests were performed on cylindrical samples a pressure column hollow cylinder calculation elastogram. An image was obtained from elastogram using geometry properties. Results similitude biological...

As speckle on ultrasonic B-scan may reveal information relative to tissue structure, the present work attempts discriminate various prostatic tissues (normal tissue, benign hypertrophy and cancer) by means of texture analysis. We select regions interest their homogeneous appearance. A pre-processing stage is required obtain stationary samples. The method used measures second-order statistics, namely co-occurrence matrices. Fairly good signatures have been obtained with parameters derived...

Deviant stimuli, violating regularities in a sensory environment, elicit the Mismatch Negativity (MMN), largely described Event-Related Potential literature. While it is widely accepted that MMN reflects more than basic change detection, comprehensive description of mental processes modulating this response still lacking. Within framework predictive coding, deviance processing part an inference process where prediction errors (the mismatch between incoming sensations and predictions...

Objectives: Prone positioning is frequently used during acute respiratory distress syndrome. However, mechanisms by which it improves oxygenation are poorly understood, as well its interaction with positive end-expiratory pressure. This study was conducted to decipher the respective effects of pressure and posture lung injury on regional ventilation, perfusion recruitment assessed positron emission tomography. Design: Experimental study. Setting: Research laboratory a university hospital....

An algorithm devoted to the segmentation of 3-D ultrasonic data is proposed. The involves adaptive clustering based on multiparametric information: gray-scale intensity echographic data, texture features calculated from envelope and tissue characterization information local frequency spectra radio-frequency signals. problem formulated as a Maximum A posterior (MAP) estimation problem. multi-resolution implementation approach tested simulated in vivo echocardiographic data. results presented...

Most pedestrian detection methods focus on bounding boxes based fusing RGB with lidar. These do not relate to how the human eye perceives objects in real world. Furthermore, lidar and vision can have difficulty detecting pedestrians scattered environments, radar be used overcome this problem. Therefore, motivation of work is explore, as a preliminary step, feasibility lidar, radar, for that potentially autonomous driving uses fully connected convolutional neural network architecture...

A novel approach for correcting intensity nonuniformity in magnetic resonance imaging (MRI) is presented. This based on the simultaneous use of spatial and gray-level histogram information. Spatial information about obtained using cubic B-spline smoothing. Gray-level image corrupted by exploited from a frequential point view. The proposed correction method illustrated both physical phantom human brain images. results are consistent with theoretical prediction, demonstrate new way dealing...

No AccessJournal of UrologyClinical Urology: Original Articles1 Oct 1998IMAGE BASED RENAL STONE TRACKING TO IMPROVE EFFICACY IN EXTRACORPOREAL LITHOTRIPSY MACIEJ ORKISZ, TEYMOUR FARCHTCHIAN, DJILLALI SAIGHI, MAURICE BOURLION, NICOLAS THIOUNN, GERARD GIMENEZ, BERNARD DEBRE, and THIERRY A. FLAM ORKISZMACIEJ ORKISZ More articles by this author , FARCHTCHIANTEYMOUR FARCHTCHIAN SAIGHIDJILLALI SAIGHI BOURLIONMAURICE BOURLION THIOUNNNICOLAS THIOUNN GIMENEZGERARD GIMENEZ DEBREBERNARD DEBRE...

The present work concerns the problem of refraction artifacts in ultrasonic transmission tomography. reconstruction is improved by curved-ray methods, combined with algebraic techniques. acoustic ray tracing and image interpolation has been carefully studied, different algorithms have developed compared. effect geometrical characteristics set-up studied medium (geometry acoustical properties) on accuracy are considered. Some simulation results presented which show an encouraging reduction...

Light pulses (sonoluminescence) and pressure produced by the collapse of cavitation bubbles are investigated simultaneously means an optical cable connected to a photomultiplier (PM) miniature piezoelectric probe. All collapses do not systematically lead occurrence pulse on PM anode. The maximum is one anodic per 4.6 ultrasonic periods. Pulse height analysis indicates that most probable producing emission photoelectron photocathode PM. Simultaneous shows no correlation exists between heights...

In ultrasound imaging, robustness of the diagnosis can be improved by using many images parameters. this paper we propose a hybrid approach for improving multi-parametric mean shift filtering (MPMS). Multi-parametric is really attractive since it works conjointly in spatial-range domain, taking into account spatial location data as well range values Hybrid MPMS an. iterative method that combines two procedures called nonblurring and blurring. Our was positively tested on set simulated data....

We propose a new robust adaptive region growing method (RoAd RG) based on two local parameters: the mean value of intensity function and norm gradient. This approach enables better spread inside interest while avoiding merge outlier pixels. tested our synthesized noisy image, demonstrated that RoAd RG gives result than non or not fully methods. applied positively to 3D [18F]fluoride ion PET images for segmenting bone structures, showed its superiority compared method.

In this paper, intravascular ultrasound (IVUS) images acquired with a 64-element array transducer using multistatic acquisition scheme are presented. The reconstructed from collection of pulse-echo measurements synthetic aperture imaging technique. main limitations IVUS poor lateral resolution and elevated grating lobes caused by the geometry. We propose Synthetic Aperture Focusing Technique (SAFT), which uses limited number A-scan signals. focusing process, is performed in Fourier domain,...

During the process of validation a new tracer, estimation performance and processing algorithms have to be investigated with data sets representative ground truth. Because this truth is hardly accessible in positron emission tomography (PET), validations often rely on use simulated sets. Considering that Monte Carlo simulators are very time consuming not easy use, building publicly available databases PET volumes becoming highly desirable. We present here methodology employed for creation...

/sup 18/F-labeled NaF, also called [/sup 18/F] fluoride ion, Positron Emission Tomography (NaF PET) is a specific imaging modality of bone activity and allows tumor detection. In this paper, we propose fast-automated method for the location anatomical structures by special planes seeds in whole body NaF PET images. This step crucial registration segmentation processes such as region growing. Our proceeds two steps: first, it delineates objects bladder, skull, spine legs with horizontal...