Automatic alignment of standard views for transesophageal echocardiographic images.

Purpose: 3D transesophageal echocardiography (TEE) has become an important modality for pre- and peri-operative imaging of valvular heart disease. TEE can give excellent visualization of valve morphology in 3D rendering. As a convention, 3D TEE images are reformatted in three standard views.

Mitral Annulus Segmentation Using Deep Learning in 3-D Transesophageal Echocardiography.

3D Transesophageal Echocardiography is an excellent tool for evaluating the mitral valve and is also well suited for guiding cardiac interventions. We introduce a fully automatic method for mitral annulus segmentation in 3D Transesophageal Echocardiography, which requires no manual input. One hundred eleven multi-frame 3D transesophageal echocardiography recordings were split into training, validation, and test sets.

An image fusion tool for echo-guided left ventricular lead placement in cardiac resynchronization therapy: Performance and workflow integration analysis.

Background: The response rate to cardiac resynchronization therapy (CRT) may be improved if echocardiographic-derived parameters are used to guide the left ventricular (LV) lead deployment. Tools to visually integrate deformation imaging and fluoroscopy to take advantage of the combined information are lacking.

Methods: An image fusion tool for echo-guided LV lead placement in CRT was developed.

Comparing Comprehension of a Long Text Read in Print Book and on Kindle: Where in the Text and When in the Story?

Digital reading devices such as Kindle differ from paper books with respect to the kinesthetic and tactile feedback provided to the reader, but the role of these features in reading is rarely studied empirically. This experiment compares reading of a long text on Kindle DX and in print. Fifty participants (24 years old) read a 28 page (∼1 h reading time) long mystery story on Kindle or in a print pocket book and completed several tests measuring various levels of reading comprehension: engagement, recall, capacities to locate events in the text and reconstructing the plot of the story.

Transcatheter heart valve interventions: where are we? Where are we going?

Transcatheter heart valve interventions have transformed the outcomes of patients with valvular heart disease (VHD) who are unfavourable candidates for surgery. Technological advances have allowed extension of these interventions to younger or lower risk patients and those with other forms of VHD and may in the future permit earlier treatment of VHD in less symptomatic patients or those with moderate disease. The balance of risks and benefits is likely to differ between lower and higher risk patients, and more evidence is needed to evaluate the net benefit of transcatheter technology in these groups.

Adaptive Color Gain for Vena Contracta Quantification in Valvular Regurgitation.

Severe valvular regurgitation can lead to pulmonary hypertension, atrial fibrillation and heart failure. Vena contracta width is used to estimate the severity of the regurgitation. Parameters affecting visualization of color Doppler have a significant impact on the measurement.

Left atrial volumetric assessment using a novel automated framework for 3D echocardiography: a multi-centre analysis.

Aims: This study aims at validating a software tool for automated segmentation and quantification of the left atrium (LA) from 3D echocardiography.

Methods And Results: The LA segmentation tool uses a dual-chamber model of the left side of the heart to automatically detect and track the atrio-ventricular plane and the LA endocardium in transthoracic 3D echocardiography. The tool was tested in a dataset of 121 ultrasound images from patients with several cardiovascular pathologies (in a multi-centre setting), and the resulting volumes were compared with those assessed manually by experts in a blinded analysis using conventional contouring.

Stimulus-Response Compatibility Effect in the Near-Far Dimension: A Developmental Study.

The present study investigates the developmental aspect of stimulus-response compatibility (SRC) effect in 8-11-years-old children. The task consisted in manually responding to the color of a pawn presented on a chessboard at different distances. Manual responses were provided by reaching a proximal or distal location depending on the color of the stimulus.

Spatiotemporal registration of multiple three-dimensional echocardiographic recordings for enhanced field of view imaging.

The use of three-dimensional (3-D) echocardiography is limited by signal dropouts and narrow field of view. Data compounding is proposed as a solution to overcome these limitations by combining multiple 3-D recordings to form a wide field of view. The first step of the solution requires registration between the recordings both in the spatial and temporal dimension for dynamic organs such as the heart.

Automated Segmentation of the Right Ventricle in 3D Echocardiography: A Kalman Filter State Estimation Approach.

As the right ventricle's (RV) role in cardiovascular diseases is being more widely recognized, interest in RV imaging, function and quantification is growing. However, there are currently few RV quantification methods for 3D echocardiography presented in the literature or commercially available. In this paper we propose an automated RV segmentation method for 3D echocardiographic images.

Parametric ultrasound and fluoroscopy image fusion for guidance of left ventricle lead placement in cardiac resynchronization therapy.

Recent studies show that the response rate to cardiac resynchronization therapy (CRT) could be improved if the left ventricle (LV) is paced at the site of the latest mechanical activation, but away from the myocardial scar. A prototype system for CRT lead placement guidance that combines LV functional information from ultrasound with live x-ray fluoroscopy was developed. Two mean anatomical models, each containing LV epi-, LV endo- and right ventricle endocardial surfaces, were computed from a database of 33 heart failure patients as a substitute for a patient-specific model.

Enhancing bull sexual behavior using estrus-specific molecules identified in cow urine.

Deficiencies in bull mating behavior have implications for bovine artificial insemination activities. The aim of this study was to identify the compounds present in fluids emitted by cows during estrus, which could enhance bull libido. Chemical analysis of urine samples from cows led to the characterization of molecules varying specifically at the preestrous and estrous stages.

Preparation of forefinger's sequence on keyboard orients ocular fixations on computer screen.

This study examined the links between attention, hand movements and eye movements when performed in different spatial areas. Participants performed a visual search task on a computer screen while preparing to press two keyboard keys sequentially with their index. Results showed that the planning of the manual sequence influenced the latency of the first saccade and the placement of the first fixation.

Motor transfer from map ocular exploration to locomotion during spatial navigation from memory.

Spatial navigation from memory can rely on two different strategies: a mental simulation of a kinesthetic spatial navigation (egocentric route strategy) or visual-spatial memory using a mental map (allocentric survey strategy). We hypothesized that a previously performed "oculomotor navigation" on a map could be used by the brain to perform a locomotor memory task. Participants were instructed to (1) learn a path on a map through a sequence of vertical and horizontal eyes movements and (2) walk on the slabs of a "magic carpet" to recall this path.

Accuracy of measuring mitral annular velocity by 2D speckle tracking imaging.

Background: Recent developments in 2D speckle tracking imaging allow not only measurements of regional myocardial strain, but also velocities of the mitral annulus. The aim of this study was to determine the accuracy of speckle tracking derived mitral annulus velocity compared with conventional pulsed wave Doppler measurements.

Methods: 2D speckle tracking was acquired from the apical 4-chamber view (QLab, Speckle SQ, Philips, Andover, MA) in 169 subjects.

Visual objects can potentiate a grasping neural simulation which interferes with manual response execution.

Previous studies on visuomotor priming have provided insufficient information to determine whether the reach-to-grasp potentiation of a non-target object produces a specific effect during response execution. In order to answer this question, subjects were instructed to reach and grasp a response device with either a power or a precision grip, depending on whether the stimulus they saw was empty or full. Stimuli consisted of containers (graspable with either a power or a precision grip), with non-graspable stimuli added as a control condition (geometrical shapes).

Assessment of subendocardial vs. subepicardial left ventricular rotation and twist using two-dimensional speckle tracking echocardiography: comparison with tagged cardiac magnetic resonance.

Aims: The aim of this article is to evaluate the accuracy and reproducibility of two-dimensional speckle tracking echocardiography (2D-STE) for the estimation of left ventricular (LV) twist, using tagged cardiac magnetic resonance (cMR) as the reference standard, and to assess how much 2D-STE rotational parameters are affected by the level at which measurements are made within the LV.

Methods And Results: Forty-three patients with various heart diseases and 10 healthy volunteers underwent cMR and 2D-STE on the same day. With both methods, basal and apical time-rotation curves were generated at endocardial, midwall, and epicardial levels.

Measurement of left ventricular mass by real-time three-dimensional echocardiography: validation against magnetic resonance and comparison with two-dimensional and m-mode measurements.

Background: The recent development of 3-dimensional (3D) surface detection algorithm of the endocardial and epicardial surfaces from real-time 3D echocardiographic (RT3DE) datasets allows direct semiautomated quantification of left ventricular mass (LVM). Our aims were to (1) evaluate the accuracy of RT3DE measurements of LVM using this algorithm against cardiac magnetic resonance (CMR) reference and (2) compare RT3DE LVM with conventional M-mode, 2-dimensional (2D), and RT3DE-guided biplane measurements.

Methods: A total of 205 patients were studied in 2 protocols: (1) RT3DE and CMR imaging was performed on the same day in 55 subjects; (2) in an additional 150 subjects, RT3DE, 2D, and M-mode images were acquired.

Ocular pursuit and visual memory of moving shapes.

This paper deals with visual memory of moving shapes. During a visual recognition task, shapes moved on a computer screen, at a constant speed, and in a direction that was either similar, orthogonal or opposite to the direction of motion during learning. Results showed that correct response rate varies according to oculomotor factors: (1) the motor skill of ocular pursuit during learning and (2) the compatibility between motor control of ocular pursuits during learning and recognition.

Review of myocardial motion estimation methods from optical flow tracking on ultrasound data.

Quantitative analysis of cardiac motion is of great clinical interest in assessment of ventricular function. Ultrasound imaging, especially matrix transducers acquiring real-time three dimensional data, provide valuable information, from which quantitative measures of cardiac function can be extracted via optical flow computation. Such analysis requires tracking of the image brightness patterns with underlying assumptions of visual persistency.

Integrating functional and anatomical information to facilitate cardiac resynchronization therapy.

Multiple imaging modalities are required in patients receiving cardiac resynchronization therapy. We have developed a strategy to integrate echocardiographic and angiographic information to facilitate left ventricle (LV) lead position. Full three-dimensional LV-volumes (3DLVV) and dyssynchrony maps were acquired before and after resynchronization.

Dynamic cardiac information from optical flow using four dimensional ultrasound.

Quantitative analysis of cardiac motion is of great clinical interest in assessing ventricular function. Real-time 3-D (RT3D) ultrasound transducers provide valuable three-dimensional information, from which quantitative measures of cardiac function can be extracted. Such analysis requires segmentation and visual tracking of the left ventricular endocardial border.

Visuomotor priming of a manual reaching movement during a perceptual decision task.

This paper deals with the mental simulation of manual movement that sometimes accompanies the visual perception of an object. Previous studies investigated how visual objects prime the grasping manual movement they afford. The principal purpose of the present experiment was to determine if such visuomotor priming also concerns the reaching manual movement that visual objects afford.

Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data.

Aims: Determination of left ventricular (LV) volumes and ejection fraction (EF) from two-dimensional echocardiographic (2DE) images is subjective, time-consuming, and relatively inaccurate because of foreshortened views and the use of geometric assumptions. Our aims were (1) to validate a new method for rapid, online measurement of LV volumes from real-time three-dimensional echocardiographic (RT3DE) data using cardiac magnetic resonance (CMR) as the reference and (2) to compare its accuracy and reproducibility with standard 2DE measurements.

Methods And Results: CMR, 2DE, and RT3DE datasets were obtained in 50 patients.