1,721,049 research outputs found
Vortex imaging: new information gain from tracking cardiac energy loss
No full textEditorial on the manuscript: Stugaard M, Koriyama H, Katsuki K, Masuda K, Asanuma T, Takeda Yet al. Energy loss in the left ventricle obtained by vector flow mapping as a new quantitative measure of severity of aortic regurgitation. a combined experimental and clinical study. EurHeart J, Cardiovasc Imag 2015; (same issue)
Tissue Tracking Technology for Assessing Cardiac Mechanics
No full textTissue tracking technologies such as speckle tracking echocardiography and feature tracking cardiac magnetic resonance have enhanced the noninvasive assessment of myocardial deformation in clinical research and clinical practice. The widespread enthusiasm for using tissue tracking techniques in research and clinical practice stems from the ready applicability of these technologies to routine echocardiographic or cardiac magnetic resonance images. The technology is common to both modalities, and derived parameters to describe myocardial mechanics are the similar, albeit with different accuracies. We provide an overview of the normal values and reproducibility of the clinically applicable parameters, together with their clinical validation. The use of these technologies in different clinical scenarios, and the additive value to current imaging diagnostics are discussed
Precision Phenotyping in Heart Failure and Pattern Clustering of Ultrasound Data for the Assessment of Diastolic Dysfunction
Full text linkOBJECTIVES The aim of this study was to investigate whether cluster analysis of left atrial and left ventricular (LV)
mechanical deformation parameters provide sufficient information for Doppler-independent assessment of LV diastolic
function.
BACKGROUND Medical imaging produces substantial phenotyping data, and superior computational analyses could
allow automated classification of repetitive patterns into patient groups with similar behavior.
METHODS The authors performed a cluster analysis and developed a model of LV diastolic function from an initial
exploratory cohort of 130 patients that was subsequently tested in a prospective cohort of 44 patients undergoing
cardiac catheterization. Patients in both study groups had standard echocardiographic examination with Doppler-derived
assessment of diastolic function. Both the left ventricle and the left atrium were tracked simultaneously using
speckle-tracking echocardiography (STE) for measuring simultaneous changes in left atrial and ventricular volumes,
volume rates, longitudinal strains, and strain rates. Patients in the validation group also underwent invasive
measurements of pulmonary capillary wedge pressure and LV end diastolic pressure immediately after echocardiography.
The similarity between STE and conventional 2-dimensional and Doppler methods of diastolic function was
investigated in both the exploratory and validation cohorts.
RESULTS STE demonstrated strong correlations with the conventional indices and independently clustered the patients
into 3 groups with conventional measurements verifying increasing severity of diastolic dysfunction and LV filling
pressures. A multivariable linear regression model also allowed estimation of E/e0 and pulmonary capillary
wedge pressure by STE in the validation cohort.
CONCLUSIONS Tracking deformation of the left-sided cardiac chambers from routine cardiac ultrasound images provides
accurate information for Doppler-independent phenotypic characterization of LV diastolic function and noninvasive assessment
of LV filling pressures
Intelligent Platforms for Disease Assessment Novel Approaches in Functional Echocardiography
No full textAccelerating trends in the dynamic digital era (from 2004 onward) has resulted in the emergence of novel parametric imaging tools that allow easy and accurate extraction of quantitative information from cardiac images. This review principally attempts to heighten the awareness of newer emerging paradigms that may advance acquisition, visualization and interpretation of the large functional data sets obtained during cardiac ultrasound imaging. Incorporation of innovative cognitive software that allow advanced pattern recognition and disease forecasting will likely transform the human-machine interface and interpretation process to achieve a more efficient and effective work environment. Novel technologies for automation and big data analytics that are already active in other fields need to be rapidly adapted to the health care environment with new academic-industry collaborations to enrich and accelerate the delivery of newer decision making tools for enhancing patient care
Exploring Left Ventricular Isovolumic Shortening and Stretch Mechanics⁎⁎Editorials published in JACC: Cardiovascular Imaging reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Imaging or the American College of Cardiology. “The heart has its reasons...”††Quotation by Blaise Pascal. Available at: http://www.quotationspage.com/quote/1893.html. Accessed December 28, 2008.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Definitions for a common standard for 2D speckle tracking echocardiography: consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging
Full text linkRecognizing the critical need for standardization in strain imaging, in 2010, the European Association of Echocardiography (now the European Association of Cardiovascular Imaging, EACVI) and the American Society of Echocardiography (ASE) invited technical representatives from all interested vendors to participate in a concerted effort to reduce intervendor variability of strain measurement. As an initial product of the work of the EACVI/ASE/Industry initiative to standardize deformation imaging, we prepared this technical document which is intended to provide definitions, names, abbreviations, formulas, and procedures for calculation of physical quantities derived from speckle tracking echocardiography and thus create a common standard
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