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The implication of 3D echocardiography derived left atrial anatomy and volumetric analysis in clinical routine
No full textA háromdimenziós echokardiográfia (3DE) - túllépve a 2D módszer korlátain – specifikus transzoesophageális vizsgálati protokoll használatával alkalmas valamennyi pulmonális vénáról megfelelő minőségű felvételek készítésére. Ezen módszerrel a 3D TEE a CT alternatívája lehet a pulmonális vénák anatómiai sajátosságainak megjelenítésében, ezáltal a pulmonális véna izoláció előtti kivizsgálásban.
A 3DE-val mért bal pitvari minimum volumen alkalmas a prekapilláris és a posztkapilláris pulmonális hypertoniában szenvedő betegek elkülönítésére. A 3D bal pitvari minimum térfogat hatékonyabban képes különbséget tenni a pulmonális hypertoniás betegcsoportok között, mint a bal pitvari maximális volumen, vagy a bal és a jobb pitvari térfogatok aránya. Ha a bal pitvari minimum volument a bal kamrai végdiasztolés volumennel kombináljuk, akkor az előbbi paraméter differenciáldiagnosztikai képessége tovább növelhető.
7.1. Új eredmények, megállapítások:
1. Az általunk módosított módszer a pulmonális vénák háromdimenziós transzoesophageális képalkotására képes valamennyi tüdővénáról 3D felvételeket előállítani.
2. A módosított felvételi protokoll alappillére a beteg pozíciójának vizsgálat közbeni módosítása.
3. A kifejlesztett módszerrel 93%-ban kiváló minőségben lehetett a pulmonális vénákat megjeleníteni.
4. A 3D echocardiográfiás vizsgálattal mérhető testfelszínre indexált bal pitvari minimum volumen alkalmas non-invazív paraméter a pulmonális hypertonia differenciáldiagnosztikájában, a prekapilláris és posztkapilláris forma elkülönítésére.
5. Az indexált bal pitvari minimum volumen differenciáldiagnosztikai értéke jobb, mint a pitvari volumen aránynak vagy a maximális bal pitvari volumennek önmagában.
6. A differenciáló képességét tovább növeli, amennyiben a 3D echo által mért pitvari minimum volument a bal kamrai végdiasztolés térfogat értékkel kombináljuk.Three-dimensional echocardiography (3DE), beyond the limits of the 2D method, is suitable for taking high-quality images of all pulmonary veins using a specific transoesophageal (TEE) examination protocol. This specific 3D TEE protocol can be an alternative tool of CT in examining and visualizing the pulmonary vein’s anatomical features before the pulmonary vein isolation.
The left atrial minimum volume measured by 3DE is suitable for differentiating patients with precapillary and postcapillary pulmonary hypertension. 3D left atrial minimum volume is more effective in differentiating the patients with different types of pulmonary hypertension than left ventricular maximal volume or the atrial volume ratio. The differentiation ability could be improved if the 3DE measured atrial minimum volume data combined with the left ventricular end-diastolic volume.
8.1. New results, findings:
1. Our modified method for visualization pulmonary veins by three-dimensional transesophageal echocardiography is able to produce 3D images of all pulmonary veins.
2. Modification of the patient's position during the examination is the cornerstone of the modified protocol for displaying the pulmonary veins.
3. The developed method was able to display pulmonary veins with high quality in 93%.
4. The body surface area indexed left atrial minimum volume measured by 3D echocardiography is a suitable non-invasive parameter in the differential diagnosis of pulmonary hypertension distinguishing between the precapillary and postcapillary forms.
5. The differential diagnostic value of the indexed left atrial minimum volume is better than the atrial volume ratio or the left atrial maximum volume alone.
6. The ability to differentiate between the precapillary and postcapillary pulmonary hypertension form is further enhanced if the atrial minimum volume measured by the 3D echo is combined with the left ventricular end-diastolic volume value
Determinants of normal tricuspid annulus area in healthy volunteers: a three-dimensional echocardiographic study
No full textNew speckle-tracking algorithm for right ventricular volume analysis from three-dimensional echocardiographic data sets: validation with cardiac magnetic resonance and comparison with the previous analysis tool
No full textAIMS: (i) To validate a new software for right ventricular (RV) analysis by 3D echocardiography (3DE) against cardiac magnetic resonance (CMR); (ii) to assess the accuracy of different measurement approaches; and (iii) to explore any benefits vs. the previous software.
METHODS AND RESULTS: We prospectively studied with 3DE and CMR 47 patients (14-82 years, 28 men) having a wide range of RV end-diastolic volumes (EDV 82-354 mL at CMR) and ejection fractions (EF 34-81%). Multi-beat RV 3DE data sets were independently analysed with the new software using both automated and manual editing options, as well as with the previous software. RV volume reproducibility was tested in 15 random patients. RV volumes and EF measurements by the new software had an excellent accuracy (bias ± SD: -15 ± 24 mL for EDV; 1.4 ± 4.9% for EF) and reproducibility compared with CMR, provided that the RV borders automatically tracked by software were systematically edited by operator. The automated analysis option underestimated the EDV, overestimated the ESV, and largely underestimated the EF (bias ± SD: -17 ± 10%). RV volumes measured with the new software using manual editing showed similar accuracy, but lower inter-observer variability and shorter analysis time (3-5') in comparison with the previous software.
CONCLUSION: Novel vendor-independent 3DE software enables an accurate, reproducible and faster quantitation of RV volumes and ejection fraction. Rather than optional, systematic verification of border tracking quality and manual editing are mandatory to ensure accurate 3DE measurements. These findings are relevant for echocardiography laboratories aiming to implement 3DE for RV analysis for both research and clinical purposes
In patients with functional tricuspid regurgitation, tricuspid annulus size by three-dimensional echocardiography is related to right heart chamber volumes
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Going 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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