Indium-111 platelet scintigraphy and two-dimensional echocardiography for detection of left ventricular thrombus: influence of clot size and age

International Nuclear Information System (INIS)

Seabold, J.E.; Schroeder, E.C.; Conrad, G.R.

1987-01-01

Two-dimensional echocardiography and indium-111 platelet scintigraphy were performed on 50 dogs to determine the influence of clot age and size on the detection of experimentally induced left ventricular mural thrombus. Thrombus was induced by apical infarction and injection of a sclerosing agent and thrombin. The animals were classified into four groups according to the time of indium-111 platelet injection after thrombus induction: Group I (17 dogs, 1/2 hour after induction; 3 dogs, before induction), Group II (12 dogs, 24 hours after induction) and Group III (12 dogs, 1 week after induction). In Group IV (six control dogs) apical infarction was produced, but thrombin was not injected; indium-111 platelets were injected 1/2 to 1 hour after infarction. The dogs were studied by indium-111 platelet scintigraphy and by two-dimensional echocardiography 1/2 to 5 hours (Group I) and 1 to 5 and up to 72 hours (Groups II to IV) after platelet administration and before death was induced. Two-dimensional echocardiography showed the best overall sensitivity for detection of acute thrombus (97%; 29 of 30). The sensitivity of indium-111 platelet scintigraphy was 86% (18 of 21) for clots greater than or equal to 0.08 ml in size, and 67% (20 of 30) for detection of all clots. Thrombus did not form in 14 dogs of Groups I to III and in 6 of 6 control dogs. The specificity of scintigraphy was 100% (20 of 20) compared with 80% (16 of 20) for echocardiography. Echocardiography was more sensitive than scintigraphy for detecting very small clots in this experimental model

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography.

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Shahgaldi, Kambiz; Gudmundsson, Petri; Manouras, Aristomenis; Brodin, Lars-Ake; Winter, Reidar

2009-08-25

Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method. Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 +/- 3.7% and -0.2 +/- 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

Preliminary study of the application of transthoracic echocardiography-guided three-dimensional printing for the assessment of structural heart disease.

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Zhu, Yanbo; Liu, Jianshi; Wang, Lianqun; Guan, Xin; Luo, Yongjuan; Geng, Jie; Geng, Qingguo; Lin, Yunjia; Zhang, Lixia; Li, Xixue; Lu, Yaping

2017-12-01

To investigate the feasibility and diagnostic value of a preoperative transthoracic echocardiography-guided three-dimensional printed model (TTE-guided 3DPM) for the assessment of structural heart disease (SHD). Fourty-four patients underwent cardiac surgery at Tianjin Chest Hospital. The patients were preoperatively assessed using TTE-guided 3DPM, which was compared to conventional three-dimensional transthoracic echocardiography (3DTTE) along with direct intraoperative findings, which were considered the "gold standard." Twelve patients had SHD, including four with mitral prolapse, two with partial endocardial cushion defects, two with secondary atrial septal defects, two with rheumatic mitral stenosis, one with tetralogy of Fallot, and one with a ventricular septal defect (VSD). Thirty-two patients who did not have SHDs were designated as the negative control group. The sensitivity and specificity of the TTE-guided 3DPM were greater than or equal to those of the 3DTTE. The P-value of the McNemar test of 3DTTE was >.05, which indicates that the difference was not statistically significant (Kappa = 0.745, P guided 3DPM was >.05, which indicates that the difference was not statistically significant (Kappa = 0.955, P guided 3DPM resulted in a P-value >.05, which indicates that the difference was not statistically significant (Kappa = 0.879, P guided 3DPM displayed the 3D structure of SHDs and cardiac lesions clearly and was consistent with the intra-operative findings. Transthoracic echocardiography-guided three-dimensional printed model (TTE-guided 3DPM) provides essential information for preoperative evaluation and decision making for patients with SHDs. © 2017, Wiley Periodicals, Inc.

Temporal enhancement of two-dimensional color doppler echocardiography

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Terentjev, Alexey B.; Settlemier, Scott H.; Perrin, Douglas P.; del Nido, Pedro J.; Shturts, Igor V.; Vasilyev, Nikolay V.

2016-03-01

Two-dimensional color Doppler echocardiography is widely used for assessing blood flow inside the heart and blood vessels. Currently, frame acquisition time for this method varies from tens to hundreds of milliseconds, depending on Doppler sector parameters. This leads to low frame rates of resulting video sequences equal to tens of Hz, which is insufficient for some diagnostic purposes, especially in pediatrics. In this paper, we present a new approach for reconstruction of 2D color Doppler cardiac images, which results in the frame rate being increased to hundreds of Hz. This approach relies on a modified method of frame reordering originally applied to real-time 3D echocardiography. There are no previous publications describing application of this method to 2D Color Doppler data. The approach has been tested on several in-vivo cardiac 2D color Doppler datasets with approximate duration of 30 sec and native frame rate of 15 Hz. The resulting image sequences had equivalent frame rates to 500Hz.

Three-dimensional adult echocardiography: where the hidden dimension helps.

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Mor-Avi, Victor; Sugeng, Lissa; Lang, Roberto M

2008-05-01

The introduction of three-dimensional (3D) imaging and its evolution from slow and labor-intense off-line reconstruction to real-time volumetric imaging is one of the most significant developments in ultrasound imaging of the heart of the past decade. This imaging modality currently provides valuable clinical information that empowers echocardiography with new levels of confidence in diagnosing heart disease. One major advantage of seeing the additional dimension is the improvement in the accuracy of the evaluation of cardiac chamber volumes by eliminating geometric modeling and the errors caused by foreshortened views. Another benefit of 3D imaging is the realistic views of cardiac valves capable of demonstrating numerous pathologies in a unique, noninvasive manner. This article reviews the major technological developments in 3D echocardiography and some of the recent literature that has provided the scientific basis for its clinical use.

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

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Manouras Aristomenis

2009-08-01

Full Text Available Abstract Background Visual assessment of left ventricular ejection fraction (LVEF is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE and triplane echocardiography (TPE using quantitative real-time three-dimensional echocardiography (RT3DE as the reference method. Methods Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. Results There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively. Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Conclusion Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

Early detection of myocardial dysfunction using two-dimensional speckle tracking echocardiography in a young cat with hypertrophic cardiomyopathy

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Ryohei Suzuki

2018-02-01

Full Text Available Case summary A 5-month-old intact female Scottish Fold cat was presented for cardiac evaluation. Careful auscultation detected a slight systolic murmur (Levine I/VI. The findings of electrocardiography, thoracic radiography, non-invasive blood pressure measurements and conventional echocardiographic studies were unremarkable. However, two-dimensional speckle tracking echocardiography revealed abnormalities in myocardial deformations, including decreased early-to-late diastolic strain rate ratios in longitudinal, radial and circumferential directions, and deteriorated segmental systolic longitudinal strain. At the follow-up examinations, the cat exhibited echocardiographic left ventricular hypertrophy and was diagnosed with hypertrophic cardiomyopathy using conventional echocardiography. Relevance and novel information This is the first report on the use of two-dimensional speckle tracking echocardiography for the early detection of myocardial dysfunction in a cat with hypertrophic cardiomyopathy; the myocardial dysfunction was detected before the development of hypertrophy. The findings from this case suggest that two-dimensional speckle tracking echocardiography can be useful for myocardial assessment when conventional echocardiographic and Doppler findings are ambiguous.

Assessment of inter-atrial, inter-ventricular, and atrio-ventricular interactions in tetralogy of Fallot patients after surgical correction. Insights from two-dimensional speckle tracking and three-dimensional echocardiography.

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Abd El Rahman, Mohamed; Raedle-Hurst, Tanja; Rentzsch, Axel; Schäfers, Hans-Joachim; Abdul-Khaliq, Hashim

2015-10-01

We aimed to assess biatrial size and function, interactions on atrial and ventricular levels, and atrio-ventricular coupling in patients after tetralogy of Fallot repair. A total of 34 patients with a mean age of 20.9±9 years, and 35 healthy controls, underwent two-dimensional speckle tracking echocardiography for ventricular and atrial strain measurements and real-time three-dimensional echocardiography to assess ventricular and atrial volumes. When compared with controls, tetralogy of Fallot patients had significantly reduced right atrial peak atrial longitudinal strain (ptetralogy of Fallot group, left ventricular ejection fraction was negatively related to the right ventricular end-systolic volume normalised to body surface area (r=-0.62, ptetralogy of Fallot patients, biatrial dysfunction exists and can be quantified via two-dimensional speckle tracking echocardiography as well as real-time three-dimensional echocardiography. Different forms of interactions on atrial and ventricular levels are evident among such cohorts.

Two-Dimensional Echocardiography Estimates of Fetal Ventricular Mass throughout Gestation.

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Aye, Christina Y L; Lewandowski, Adam James; Ohuma, Eric O; Upton, Ross; Packham, Alice; Kenworthy, Yvonne; Roseman, Fenella; Norris, Tess; Molloholli, Malid; Wanyonyi, Sikolia; Papageorghiou, Aris T; Leeson, Paul

2017-08-12

Two-dimensional (2D) ultrasound quality has improved in recent years. Quantification of cardiac dimensions is important to screen and monitor certain fetal conditions. We assessed the feasibility and reproducibility of fetal ventricular measures using 2D echocardiography, reported normal ranges in our cohort, and compared estimates to other modalities. Mass and end-diastolic volume were estimated by manual contouring in the four-chamber view using TomTec Image Arena 4.6 in end diastole. Nomograms were created from smoothed centiles of measures, constructed using fractional polynomials after log transformation. The results were compared to those of previous studies using other modalities. A total of 294 scans from 146 fetuses from 15+0 to 41+6 weeks of gestation were included. Seven percent of scans were unanalysable and intraobserver variability was good (intraclass correlation coefficients for left and right ventricular mass 0.97 [0.87-0.99] and 0.99 [0.95-1.0], respectively). Mass and volume increased exponentially, showing good agreement with 3D mass estimates up to 28 weeks of gestation, after which our measurements were in better agreement with neonatal cardiac magnetic resonance imaging. There was good agreement with 4D volume estimates for the left ventricle. Current state-of-the-art 2D echocardiography platforms provide accurate, feasible, and reproducible fetal ventricular measures across gestation, and in certain circumstances may be the modality of choice. © 2017 S. Karger AG, Basel.

Making three-dimensional echocardiography more tangible: a workflow for three-dimensional printing with echocardiographic data

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Azad Mashari MD

2016-12-01

Full Text Available Three-dimensional (3D printing is a rapidly evolving technology with several potential applications in the diagnosis and management of cardiac disease. Recently, 3D printing (i.e. rapid prototyping derived from 3D transesophageal echocardiography (TEE has become possible. Due to the multiple steps involved and the specific equipment required for each step, it might be difficult to start implementing echocardiography-derived 3D printing in a clinical setting. In this review, we provide an overview of this process, including its logistics and organization of tools and materials, 3D TEE image acquisition strategies, data export, format conversion, segmentation, and printing. Generation of patient-specific models of cardiac anatomy from echocardiographic data is a feasible, practical application of 3D printing technology.

Comparison of indium-111 platelet scintigraphy and two-dimensional echocardiography in the diagnosis of left ventricular thrombi

International Nuclear Information System (INIS)

Ezekowitz, M.D.; Wilson, D.A.; Smith, E.O.; Burow, R.D.; Harrison, L.H. Jr.; Parker, D.E.; Elkins, R.C.; Peyton, M.; Taylor, F.B.

1982-01-01

In a study comparing indium-111 platelet scintigraphy and two-dimensional echocardiography as methods of identifying left ventricular thrombi, the results obtained with both techniques were verified at surgery or autopsy in 53 patients-34 with left ventricular aneurysms, and 19 with mitral-valve disease. Left ventricular thrombi were found at surgery or autopsy in 14 of the patients with aneurysms and in none of those with mitral-valve disease. Thirteen of 53 echocardiograms (25%) were technically inadequate and excluded from the analysis. In the group with aneurysms, the sensitivity of scintigraphy in detecting thrombi was 71%, and that of echocardiography was 77%. The specificity of scintigraphy was 100%, and that of echocardiography was 93%. We conclude that indium-111 platelet scintigraphy and two-dimensional echocardiography have useful and complementary roles in the detection of left ventricular thrombi. Both these noninvasive techniques can be used to monitor therapy

A comparison of left ventricular mass between two-dimensional echocardiography, using fundamental and tissue harmonic imaging, and cardiac MRI in patients with hypertension

International Nuclear Information System (INIS)

Alfakih, Khaled; Bloomer, Tim; Bainbridge, Samantha; Bainbridge, Gavin; Ridgway, John; Williams, Gordon; Sivananthan, Mohan

2004-01-01

Purpose: To compare left ventricular mass (LVM) as measured by two-dimensional (2D) echocardiography using two different calculation methods: truncated ellipse (TE) and area length (AL), in both fundamental and tissue harmonic imaging frequencies, to LVM as measured by, the current gold standard, cardiac magnetic resonance imaging (MRI). Turbo gradient echo (TGE) pulse sequence was utilized for MRI. Materials and methods: Thirty-two subjects with history of hypertension were recruited. The images were acquired, contours were traced and the LVM was calculated for all four different echocardiography methods as well as for the cardiac MRI method. The intra-observer variabilities were calculated. The four different echocardiography methods were compared to cardiac MRI using the method described by Bland and Altman. Results: Twenty-five subjects had adequate paired data sets. The mean LVM as measured by cardiac MRI was 162±55 g and for the four different echocardiography methods were: fundamental AL 165±55 g, harmonic AL 168±53 g, fundamental TE 148±50 g, harmonic TE 149±45 g. The intra-observer variability for cardiac MRI method, expressed as bias ± 1 standard deviation of the difference (S.D.D.), was 2.3±9.2 g and for the four different echocardiography methods were: fundamental TE 0.4±26.8 g, fundamental AL 0.6±27.0 g, harmonic TE 6.7±21.8 g, harmonic AL 6.4±22.9 g. The mean LVM for the AL method was closest to the cardiac MRI technique, while TE underestimated LVM. The 95% limits of agreement were consistently wide for all the 2D echocardiography modalities when compared with the cardiac MRI technique. Conclusion: The intra-observer variability in measurements of 2D echocardiographic LVM, together with the wide limits of agreement when compared to the gold standard (cardiac MRI) are sufficiently large to make serial estimates of LVM, of single patients or small groups of subjects, by 2D echocardiography, unreliable

The additional value of three-dimensional transesophageal echocardiography in complex aortic prosthetic heart valve endocarditis

NARCIS (Netherlands)

Tanis, Wilco; Teske, Arco J.; Van Herwerden, Lex A.; Chamuleau, Steven; Meijboom, Folkert; Budde, Ricardo P J; Cramer, MJ

2015-01-01

Background Two-dimensional transthoracic and transesophageal echocardiography (2DTTE and 2DTEE) may fail to detect signs of prosthetic heart valve (PHV) endocarditis due to acoustic shadowing. Three-dimensional (3D) TEE may have additional value; however, data are scarce. This study was performed to

Three-dimensional transesophageal echocardiography in the evaluation of aortic valve destruction by endocarditis

NARCIS (Netherlands)

Nemes, Attila; Lagrand, Wim K.; McGhie, Jackie S.; ten Cate, Folkert J.

2006-01-01

Infective endocarditis remains a serious and complex disease with significant morbidity and mortality. The aim of this study was to demonstrate the clinical usefulness of 3-dimensional transesophageal echocardiography for the spatial assessment of aortic valve endocarditis. This case showed severe

Effects of antithrombotic drugs in patients with left ventricular thrombi: assessment with indium-111 platelet imaging and two-dimensional echocardiography

International Nuclear Information System (INIS)

Stratton, J.R.; Ritchie, J.L.

1984-01-01

Patients with left ventricular thrombi not caused by recent myocardial infarction were prospectively studied by indium-111 platelet imaging and two-dimensional echocardiography to determine the reproducibility of these techniques and the short-term effects of sulfinpyrazone (200 mg four times daily), aspirin (325 mg three times daily) plus dipyridamole (75 mg three times daily), and full-dose warfarin. At baseline, all patients underwent indium-111 platelet imaging and echocardiography, and the results were positive for thrombus. In six patients on no antithrombotic drug therapy, repeat platelet scans and echocardiographic studies at 6.0 +/- 3.3 weeks remained positive and were unchanged. In seven patients studied on sulfinpyrazone, three platelet scans became negative, two became equivocal, and two were unchanged; the presence and size of thrombus was constant by echocardiography in all seven patients. Of the six patients studied on aspirin plus dipyridamole, one platelet scan became negative, those of three became equivocal, and two were unchanged; all echocardiographic findings remained positive, but one patient had decreased thrombus size. Among four warfarin-treated patients, three had resolution of platelet deposition and one was unchanged; by echocardiography, thrombus resolved in one patient, was decreased in size in one, and was unchanged in two. We conclude that, in the absence of antithrombotic drug therapy, platelet imaging and echocardiographic findings are stable in patients with left ventricular thrombi not caused by recent myocardial infarction. Sulfinpyrazone, aspirin plus dipyridamole, and warfarin all interrupt platelet deposition in some patients with chronic left ventricular thrombi

Doppler echocardiography in pediatric cardiology

International Nuclear Information System (INIS)

Allen, H.D.; Marx, G.R.

1986-01-01

Congenital heart disease encompasses abnormalities in cardiac development which generally have in common either valve stenoses or connections between chambers or great vessels. Usually, abnormalities of intracardiac anatomy, and often, abnormalities of great vessel anatomy, can be unraveled by two-dimensional echocardiography. However, echocardiography offers little information regarding flow characteristics in the various congenital lesions. Addition of the Doppler principle, particularly when combined with the two-dimensional examination, can characterize the source of a flow disturbance, quantify gradients across a site of obstruction, and quantify flow volume across sites where flow is nonturbulent. These features make Doppler echocardiography unique for noninvasive accurate evaluation of children and adults with various forms of congenital heart disease. In this report, the authors discuss some of the present uses of Doppler echocardiography in congenital heart disease. Application of this technique requires greater understanding of certain physics principles than does routine echocardiography

Real-time 3-dimensional fetal echocardiography with an instantaneous volume-rendered display: early description and pictorial essay.

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Sklansky, Mark S; DeVore, Greggory R; Wong, Pierre C

2004-02-01

Random fetal motion, rapid fetal heart rates, and cumbersome processing algorithms have limited reconstructive approaches to 3-dimensional fetal cardiac imaging. Given the recent development of real-time, instantaneous volume-rendered sonographic displays of volume data, we sought to apply this technology to fetal cardiac imaging. We obtained 1 to 6 volume data sets on each of 30 fetal hearts referred for formal fetal echocardiography. Each volume data set was acquired over 2 to 8 seconds and stored on the system's hard drive. Rendered images were subsequently processed to optimize translucency, smoothing, and orientation and cropped to reveal "surgeon's eye views" of clinically relevant anatomic structures. Qualitative comparison was made with conventional fetal echocardiography for each subject. Volume-rendered displays identified all major abnormalities but failed to identify small ventricular septal defects in 2 patients. Important planes and views not visualized during the actual scans were generated with minimal processing of rendered image displays. Volume-rendered displays tended to have slightly inferior image quality compared with conventional 2-dimensional images. Real-time 3-dimensional echocardiography with instantaneous volume-rendered displays of the fetal heart represents a new approach to fetal cardiac imaging with tremendous clinical potential.

Echocardiography in the Era of Multimodality Cardiovascular Imaging

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Shah, Benoy Nalin

2013-01-01

Echocardiography remains the most frequently performed cardiac imaging investigation and is an invaluable tool for detailed and accurate evaluation of cardiac structure and function. Echocardiography, nuclear cardiology, cardiac magnetic resonance imaging, and cardiovascular-computed tomography comprise the subspeciality of cardiovascular imaging, and these techniques are often used together for a multimodality, comprehensive assessment of a number of cardiac diseases. This paper provides the general cardiologist and physician with an overview of state-of-the-art modern echocardiography, summarising established indications as well as highlighting advances in stress echocardiography, three-dimensional echocardiography, deformation imaging, and contrast echocardiography. Strengths and limitations of echocardiography are discussed as well as the growing role of real-time three-dimensional echocardiography in the guidance of structural heart interventions in the cardiac catheter laboratory. PMID:23878804

[Initial study of transthoracic echocardiography guided three-dimensional printing on the application of assessment of structural heart disease].

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Zhu, Y B; Liu, J S; Wang, L Q; Guan, X; Luo, Y J; Geng, J; Geng, Q G; Lin, Y J; Zhang, L X; Li, X X; Lu, Y P

2017-08-01

Objective: To investigate the feasibility and diagnostic value of preoperative transthoracic echocardiography guided three dimensional printing model (TTE Guided 3DPM) on the assessment of structural heart disease (SHD). Methods: From February 2016 to October 2016, 44 patients underwent cardiac surgery in Tianjin Chest Hospital, forty-four patients were assessed preoperatively using TTE Guided 3DPM, including 25 males and 19 females, aged 3-75 years, with an average of (44±22) years. compared to conventional three dimensional transthoracic echocardiography (3D-TTE), and took direct intraoperative findings as "Golden Standard" simultaneously. There are twelve patients with SHD, including four cases with mitral prolapse, two cases with partial endocardial cushion defect, two cases with secondary atrial septal defect, two cases with rheumatic mitral stenosis, one case with tetralogy of Fallot, one case with ventricular septal defect (VSD), thirty-two patients without SHD were designed as negative control. Results: The sensitivity and specificity of TTE Guided 3DPM were greater than or equal to 3D-TTE, P value of McNemar test of 3D-TTE was greater than 0.05, the difference was not statistically significant, kappa =0.745, P Guided 3DPM was greater than 0.05, the difference was not statistically significant, kappa =0.955, P Guided 3DPM and gold standards were consistent. Compared with 3D-TTE and TTE Guided 3DPM, P value was greater than 0.05, the difference was not statistically significant, kappa =0.879, P Guided 3DPM were consistent. TTE Guided 3DPM displayed the three-dimensional structure of SHD cardiac lesions clearly, which were consistent with intraoperative findings. Conclusion: TTE Guided 3DPM provides essential information for the preoperative evaluation and decision of SHD.

The history of echocardiography.

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Edler, Inge; Lindström, Kjell

2004-12-01

Following a brief review of the development of medical ultrasonics from the mid-1930s to the mid-1950s, the collaboration between Edler and Hertz that began in Lund in 1953 is described. Using an industrial ultrasonic flaw detector, they obtained time-varying echoes transcutaneously from within the heart. The first clinical applications of M-mode echocardiography were concerned with the assessment of the mitral valve from the shapes of the corresponding waveforms. Subsequently, the various M-mode recordings were related to their anatomical origins. The method then became established as a diagnostic tool and was taken up by investigators outside Lund, initially in China, Germany, Japan and the USA and, subsequently, world-wide. The diffusion of echocardiography into clinical practice depended on the timely commercial availability of suitable equipment. The discovery of contrast echocardiography in the late 1960s further validated the technique and extended the range of applications. Two-dimensional echocardiography was first demonstrated in the late 1950s, with real-time mechanical systems and, in the early 1960s, with intracardiac probes. Transesophageal echocardiography followed, in the late 1960s. Stop-action two-dimensional echocardiography enjoyed a brief vogue in the early 1970s. It was, however, the demonstration by Bom in Rotterdam of real-time two-dimensional echocardiography using a linear transducer array that revolutionized and popularized the subject. Then, the phased array sector scanner, which had been demonstrated in the late 1960s by Somer in Utrecht, was applied to cardiac studies from the mid-1970s onwards. Satomura had demonstrated the use of the ultrasonic Doppler effect to detect tissue motion in Osaka in the mid-1950s and the technique was soon afterwards applied in the heart, often in combination with M-mode recording. The development of the pulsed Doppler method in the late 1960s opened up new opportunities for clinical innovation. The

Incremental value of three-dimensional transesophageal echocardiography over two-dimensional transesophageal echocardiography in the assessment of Lambl's excrescences and nodules of Arantius on the aortic valve.

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Dumaswala, Bhavin; Dumaswala, Komal; Hsiung, Ming Chon; Quiroz, Luis David Meggo; Sungur, Aylin; Escanuela, Maximilliano German Amado; Mehta, Kruti; Oz, Tugba Kemaloglu; Bhagatwala, Kunal; Karia, Nidhi M; Nanda, Navin C

2013-09-01

In this retrospective study, we identified 7 cases where Lambl's excrescences were identified by two-dimensional transesophageal echocardiography (2DTEE) and also had live/real time three-dimensional transesophageal echocardiography (3DTEE) studies available for comparison. We subsequently assessed them for the presence of Lambl's excrescences (LE) and nodules of Arantius (NA) on the aortic valve. After their identification, we qualitatively and quantitatively organized our findings by number, cusp location, measurements, and orientation if applicable. A greater number of LE was found by 3DTEE than 2DTEE (19 vs. 11, respectively). In all 3DTEE studies, their cusp attachment site, their x-, y-, and z-axis measurements, and orientation were clearly visualized and described. Only 3DTEE studies provided confident visualization of the cusp attachment sites. Similarly, a greater number of NA was found by 3DTEE than 2DTEE (21 vs. 5, respectively). The triad of NA was visualized in all 3DTEE studies and each was described using its x-, y-, and z- axis measurements. Only three 2DTEE studies provided reliable identification of the NA. In conclusion, we present further evidence of the incremental value of 3DTEE over 2DTEE in the qualitative and quantitative assessment of cardiac structures including LE and NA on the aortic valve. © 2013, Wiley Periodicals, Inc.

Anatomical features of acute mitral valve repair dysfunction: Additional value of three-dimensional echocardiography.

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Derkx, Salomé; Nguyen, Virginia; Cimadevilla, Claire; Verdonk, Constance; Lepage, Laurent; Raffoul, Richard; Nataf, Patrick; Vahanian, Alec; Messika-Zeitoun, David

2017-03-01

Recurrence of mitral regurgitation after mitral valve repair is correlated with unfavourable left ventricular remodelling and poor outcome. This pictorial review describes the echocardiographic features of three types of acute mitral valve repair dysfunction, and the additional value of three-dimensional echocardiography. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Two-dimensional speckle tracking echocardiography prognostic parameters in patients after acute myocardial infarction.

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Haberka, Maciej; Liszka, Jerzy; Kozyra, Andrzej; Finik, Maciej; Gąsior, Zbigniew

2015-03-01

The aim of the study was to evaluate the left ventricle (LV) function with speckle tracking echocardiography (STE) and to assess its relation to prognosis in patients after acute myocardial infarction (AMI). Sixty-three patients (F/M = 16/47 pts; 62.33 ± 11.85 years old) with AMI (NSTEMI/STEMI 24/39 pts) and successful percutaneous coronary intervention (PCI) with stent implantation (thrombolysis in myocardial infarction; TIMI 3 flow) were enrolled in this study. All patients underwent baseline two-dimensional conventional echocardiography and STE 3 days (baseline) and 30 days after PCI. All patients were followed up for cardiovascular clinical endpoints, major adverse cardiovascular endpoint (MACE), and functional status (Canadian Cardiovascular Society and New York Heart Association). During the follow-up (31.9 ± 5.1 months), there were 3 cardiovascular deaths, 15 patients had AMI, 2 patients had cerebral infarction, 24 patients reached the MACE. Baseline LV torsion (P = 0.035), but none of the other strain parameters were associated with the time to first unplanned cardiovascular hospitalization. Univariate analysis showed that baseline longitudinal two-chamber and four-chamber strain (sLa2 0 and sLa4 0) and the same parameters obtained 30 days after the AMI together with transverse four-chamber strain (sLa2 30, sLa4 30, and sTa4 30) were significantly associated with combined endpoint (MACE). The strongest association in the univariate analysis was found for the baseline sLa2. However, in multivariable analysis only a left ventricular remodeling (LVR - 27% pts) was significantly associated with MACE and strain parameters were not associated with the combined endpoint. The assessment of LV function with STE may improve cardiovascular risk prediction in postmyocardial infarction patients. © 2014, Wiley Periodicals, Inc.

Assessment of atrial fibrillation and vulnerability in patients with Wolff-Parkinson-White syndrome using two-dimensional speckle tracking echocardiography.

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Li, Jing-Jie; Wei, Fang; Chen, Ju-Gang; Yu, Yan-Wei; Gu, Hong-Yue; Jiang, Rui; Wu, Xiu-Li; Sun, Qian

2014-01-01

The aim was to assess atrial fibrillation (AF) and vulnerability in Wolff-Parkinson-White (WPW) syndrome patients using two-dimensional speckle tracking echocardiography (2D-STE). All patients were examined via transthoracic echocardiography and 2D-STE in order to assess atrial function 7 days before and 10 days after RF catheter ablation. A postoperative 3-month follow-up was performed via outpatient visit or telephone calls. Results showed significant differences in both body mass index (BMI) and supraventricular tachycardia (SVT) duration between WPW patients and DAVNP patients (both Psyndrome may result in increased atrial vulnerability and contribute to the development of AF. Further, RF catheter ablation of AAV pathway can potentially improve atrial function in WPW syndrome patients. Two-dimensional speckle tracking echocardiography imaging in WPW patients would be necessary in the evaluation and improvement of the overall function of RF catheter ablation in a long-term follow-up period.

Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of primary cardiac malignant fibrous histiocytoma.

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Gok, Gulay; Elsayed, Mahmoud; Thind, Munveer; Uygur, Begum; Abtahi, Firoozeh; Chahwala, Jugal R; Yıldırımtürk, Özlem; Kayacıoğlu, İlyas; Pehlivanoğlu, Seçkin; Nanda, Navin C

2015-07-01

We describe a case of primary cardiac malignant fibrous histiocytoma where live/real time three-dimensional transesophageal echocardiography added incremental value to the two-dimensional modalities. Specifically, the three-dimensional technique allowed us to delineate the true extent and infiltration of the tumor, to identify characteristics of the tumor mass suggestive of its malignant nature, and to quantitatively assess the total tumor burden. © 2015, Wiley Periodicals, Inc.

Assessment of tricuspid valve annulus size, shape and function using real-time three-dimensional echocardiography

NARCIS (Netherlands)

A.M. Anwar (Ashraf); M.L. Geleijnse (Marcel); F.J. ten Cate (Folkert); F.J. Meijboom (Folkert)

2006-01-01

textabstractTricuspid annulus (TA) evaluation continues to be a major problem in the surgical decision-making process. Obviously, 2-dimensional transthoracic echocardiography (2D TTE) is limited in TA visualization due to its complex 3D shape. The study aimed to determine TA morphology, size and

A funnel shaped pannus formation above the mitral prosthetic valve diagnosed with real time three-dimensional echocardiography

Directory of Open Access Journals (Sweden)

Ezgi Polat Ocaklı

2017-09-01

Full Text Available Prosthetic valve obstruction due to pannus formation can be a life-threatening complication. We showed that real time three dimensional echocardiography has incremental value in diagnosing pannus localization and extent.

Integration of Computed Tomography and Three-Dimensional Echocardiography for Hybrid Three-Dimensional Printing in Congenital Heart Disease.

Science.gov (United States)

Gosnell, Jordan; Pietila, Todd; Samuel, Bennett P; Kurup, Harikrishnan K N; Haw, Marcus P; Vettukattil, Joseph J

2016-12-01

Three-dimensional (3D) printing is an emerging technology aiding diagnostics, education, and interventional, and surgical planning in congenital heart disease (CHD). Three-dimensional printing has been derived from computed tomography, cardiac magnetic resonance, and 3D echocardiography. However, individually the imaging modalities may not provide adequate visualization of complex CHD. The integration of the strengths of two or more imaging modalities has the potential to enhance visualization of cardiac pathomorphology. We describe the feasibility of hybrid 3D printing from two imaging modalities in a patient with congenitally corrected transposition of the great arteries (L-TGA). Hybrid 3D printing may be useful as an additional tool for cardiologists and cardiothoracic surgeons in planning interventions in children and adults with CHD.

Three-dimensional speckle tracking echocardiography allows detailed evaluation of left atrial function in hypertrophic cardiomyopathy--insights from the MAGYAR-Path Study.

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Domsik, Péter; Kalapos, Anita; Chadaide, Számi; Sepp, Róbert; Hausinger, Péter; Forster, Tamás; Nemes, Attila

2014-11-01

Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. Reduced left atrial (LA) function was demonstrated in HCM by different methods. Three-dimensional (3D) speckle tracking echocardiography (STE) has just been introduced for the evaluation of LA. This study was designed to compare 3DSTE-derived LA volumetric and strain parameters in HCM with healthy controls. The study comprised 23 consecutive HCM patients (mean age: 48.5 ± 15.1 years, 14 men). Their results were compared to 23 age- and gender-matched healthy controls. Complete two-dimensional Doppler echocardiography and 3DSTE have been performed in all cases. Calculated LA maximum (66.4 ± 20.4 mL vs. 36.0 ± 6.1 mL, P echocardiography allows detailed evaluation of LA (dys) function in HCM by volumetric and strain measurements. © 2014, Wiley Periodicals, Inc.

Incremental benefit of three-dimensional transesophageal echocardiography in the assessment of a primary pericardial hemangioma.

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Arisha, Mohammed J; Hsiung, Ming C; Nanda, Navin C; ElKaryoni, Ahmed; Mohamed, Ahmed H; Wei, Jeng

2017-08-01

Hemangiomas are rarely found in the heart and pericardial involvement is even more rare. We report a case of primary pericardial hemangioma, in which three-dimensional transesophageal echocardiography (3DTEE) provided incremental benefit over standard two-dimensional images. Our case also highlights the importance of systematic cropping of the 3D datasets in making a diagnosis of pericardial hemangioma with a greater degree of certainty. In addition, we also provide a literature review of the features of cardiac/pericardial hemangiomas in a tabular form. © 2017, Wiley Periodicals, Inc.

Real-Time Three-Dimensional Echocardiography: Characterization of Cardiac Anatomy and Function-Current Clinical Applications and Literature Review Update.

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Velasco, Omar; Beckett, Morgan Q; James, Aaron W; Loehr, Megan N; Lewis, Taylor G; Hassan, Tahmin; Janardhanan, Rajesh

2017-01-01

Our review of real-time three-dimensional echocardiography (RT3DE) discusses the diagnostic utility of RT3DE and provides a comparison with two-dimensional echocardiography (2DE) in clinical cardiology. A Pubmed literature search on RT3DE was performed using the following key words: transthoracic, two-dimensional, three-dimensional, real-time, and left ventricular (LV) function. Articles included perspective clinical studies and meta-analyses in the English language, and focused on the role of RT3DE in human subjects. Application of RT3DE includes analysis of the pericardium, right ventricular (RV) and LV cavities, wall motion, valvular disease, great vessels, congenital anomalies, and traumatic injury, such as myocardial contusion. RT3DE, through a transthoracic echocardiography (TTE), allows for increasingly accurate volume and valve motion assessment, estimated LV ejection fraction, and volume measurements. Chamber motion and LV mass approximation have been more accurately evaluated by RT3DE by improved inclusion of the third dimension and quantification of volumetric movement. Moreover, RT3DE was shown to have no statistical significance when comparing the ejection fractions of RT3DE to cardiac magnetic resonance (CMR). Analysis of RT3DE data sets of the LV endocardial exterior allows for the volume to be directly quantified for specific phases of the cardiac cycle, ranging from end systole to end diastole, eliminating error from wall motion abnormalities and asymmetrical left ventricles. RT3DE through TTE measures cardiac function with superior diagnostic accuracy in predicting LV mass, systolic function, along with LV and RV volume when compared with 2DE with comparable results to CMR.

Real-Time Three-Dimensional Echocardiography: Characterization of Cardiac Anatomy and Function—Current Clinical Applications and Literature Review Update

Directory of Open Access Journals (Sweden)

Morgan Q. Beckett

2017-03-01

Full Text Available Our review of real-time three-dimensional echocardiography (RT3DE discusses the diagnostic utility of RT3DE and provides a comparison with two-dimensional echocardiography (2DE in clinical cardiology. A Pubmed literature search on RT3DE was performed using the following key words: transthoracic, two-dimensional, three-dimensional, real-time, and left ventricular (LV function. Articles included perspective clinical studies and meta-analyses in the English language, and focused on the role of RT3DE in human subjects. Application of RT3DE includes analysis of the pericardium, right ventricular (RV and LV cavities, wall motion, valvular disease, great vessels, congenital anomalies, and traumatic injury, such as myocardial contusion. RT3DE, through a transthoracic echocardiography (TTE, allows for increasingly accurate volume and valve motion assessment, estimated LV ejection fraction, and volume measurements. Chamber motion and LV mass approximation have been more accurately evaluated by RT3DE by improved inclusion of the third dimension and quantification of volumetric movement. Moreover, RT3DE was shown to have no statistical significance when comparing the ejection fractions of RT3DE to cardiac magnetic resonance (CMR. Analysis of RT3DE data sets of the LV endocardial exterior allows for the volume to be directly quantified for specific phases of the cardiac cycle, ranging from end systole to end diastole, eliminating error from wall motion abnormalities and asymmetrical left ventricles. RT3DE through TTE measures cardiac function with superior diagnostic accuracy in predicting LV mass, systolic function, along with LV and RV volume when compared with 2DE with comparable results to CMR.

Clinical Stress Echocardiography

NARCIS (Netherlands)

S.E. Karagiannis

2007-01-01

textabstractTwo-dimensional echocardiography is a commonly used non-invasive method for the assessment of left ventricular function. It provides precise information on both global and segmental myocardial function by displaying endocardial motion and wall thickening. Dobutamine stress

Recent advances in echocardiography for valvular heart disease.

Science.gov (United States)

Hahn, Rebecca

2015-01-01

Echocardiography is the imaging modality of choice for the assessment of patients with valvular heart disease. Echocardiographic advancements may have particular impact on the assessment and management of patients with valvular heart disease. This review will summarize the current literature on advancements, such as three-dimensional echocardiography, strain imaging, intracardiac echocardiography, and fusion imaging, in this patient population.

Myocardial Strain Analysis by 2-Dimensional Speckle Tracking Echocardiography Improves Diagnostics of Coronary Artery Stenosis in Stable Angina Pectoris

DEFF Research Database (Denmark)

Biering-Sørensen, Tor; Hoffmann, Soren; Mogelvang, Rasmus

2014-01-01

BACKGROUND: Two-dimensional strain echocardiography detects early signs of left ventricular dysfunction; however, it is unknown whether myocardial strain analysis at rest in patients with suspected stable angina pectoris predicts the presence of coronary artery disease (CAD). METHODS AND RESULTS...... echocardiography was performed in the 3 apical projections. Peak regional longitudinal systolic strain was measured in 18 myocardial sites and averaged to provide global longitudinal peak systolic strain. Duke score, including ST-segment depression, chest pain, and exercise capacity, was used as the outcome...

Determination of multidirectional myocardial deformations in cats with hypertrophic cardiomyopathy by using two-dimensional speckle-tracking echocardiography.

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Suzuki, Ryohei; Mochizuki, Yohei; Yoshimatsu, Hiroki; Teshima, Takahiro; Matsumoto, Hirotaka; Koyama, Hidekazu

2017-12-01

Objectives Hypertrophic cardiomyopathy, a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of myocardial deformation with two-dimensional speckle-tracking echocardiography in cats with various stages of hypertrophic cardiomyopathy has not yet been reported. This study was designed to measure quantitatively multidirectional myocardial deformations of cats with hypertrophic cardiomyopathy. Methods Thirty-two client-owned cats with hypertrophic cardiomyopathy and 14 healthy cats serving as controls were enrolled and underwent assessment of myocardial deformation (peak systolic strain and strain rate) in the longitudinal, radial and circumferential directions. Results Longitudinal and radial deformations were reduced in cats with hypertrophic cardiomyopathy, despite normal systolic function determined by conventional echocardiography. Cats with severely symptomatic hypertrophic cardiomyopathy also had lower peak systolic circumferential strain, in addition to longitudinal and radial strain. Conclusions and relevance Longitudinal and radial deformation may be helpful in the diagnosis of hypertrophic cardiomyopathy. Additionally, the lower circumferential deformation in cats with severe hypertrophic cardiomyopathy may contribute to clinical findings of decompensation, and seems to be related to severe cardiac clinical signs. Indices of multidirectional myocardial deformations by two-dimensional speckle-tracking echocardiography may be useful markers and help to distinguish between cats with hypertrophic cardiomyopathy and healthy cats. Additionally, they may provide more detailed assessment of contractile function in cats with hypertrophic cardiomyopathy.

Dynamic 3D echocardiography in virtual reality.

NARCIS (Netherlands)

A.E. van den Bosch (Annemien); A.H.J. Koning (Anton); F.J. Meijboom (Folkert); J.S. Vletter-McGhie (Jackie); M.L. Simoons (Maarten); P.J. van der Spek (Peter); A.J.J.C. Bogers (Ad)

2005-01-01

textabstractBACKGROUND: This pilot study was performed to evaluate whether virtual reality is applicable for three-dimensional echocardiography and if three-dimensional echocardiographic 'holograms' have the potential to become a clinically useful tool. METHODS: Three-dimensional echocardiographic

A brief history of fetal echocardiography and its impact on the management of congenital heart disease.

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Maulik, Dev; Nanda, Navin C; Maulik, Devika; Vilchez, Gustavo

2017-12-01

Congenital heart disease (CHD), the most common congenital malformation, is associated with adverse outcome. Development of fetal echocardiography has made prenatal diagnosis of CHD a reality, and in the process revolutionized its management. This historical review briefly narrates this development over the decades focusing on the emergence of the primary modalities of fetal echocardiography comprised of the time-motion mode, two-dimensional B-mode, spectral Doppler, color Doppler, and three- and four-dimensional cardiac imaging. Collaboration between clinicians and engineers has been central to these advances. Also discussed are the accuracy and impact of fetal echocardiography on the management of CHD, and especially its role in the prenatal diagnosis of critical CHD in individualizing the management and improving the outcome. Despite these advances, most cases of CHD are not identified prenatally, emphasizing the continuing need for further technological and educational innovation and improvement. © 2017, Wiley Periodicals, Inc.

Can M mode and two dimensional echocardiography give a sufficient evaluation for surgeray of patients with pure mitral stenosis

International Nuclear Information System (INIS)

Balbarini, A; Tartarini, G.; Mengozzi, G.; Mariani, M.; Salvatore, L.; Barsotti, A.

1987-01-01

One hundred and twenty-six patients with rheumatic mitral stenosis were studied by M-mode and/or two-dimensional echocardiography. Eighty-nine patients were also submetted to cardiac catheterization and all 126 patients subsequently underwent mitral valve surgery (51 valvulotomy and 75 valve replacement). The mitral valve area measured by two-dimensional echocardiography showed a significant correlation both with hemodynamic (r=0.803, p 2 , respectively; likewise there was non significant difference in pulmonary vascular resistances (3.9 and 3.4 mmHg/l/min/m 2 ) between patients who showed functional improvement after surgery comparison to those who showed no improvement. Finally, coronary arteriography appeared to be necessary, before operation, only in cardiography is able to provide a satisfactory preoperative assessment of patients with mitral stenosis and that therefore these patients need not necessarily to be submitted to cardiac catheterization

"3D fusion" echocardiography improves 3D left ventricular assessment: comparison with 2D contrast echocardiography.

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Augustine, Daniel; Yaqub, Mohammad; Szmigielski, Cezary; Lima, Eduardo; Petersen, Steffen E; Becher, Harald; Noble, J Alison; Leeson, Paul

2015-02-01

Three-dimensional fusion echocardiography (3DFE) is a novel postprocessing approach that utilizes imaging data acquired from multiple 3D acquisitions. We assessed image quality, endocardial border definition, and cardiac wall motion in patients using 3DFE compared to standard 3D images (3D) and results obtained with contrast echocardiography (2DC). Twenty-four patients (mean age 66.9 ± 13 years, 17 males, 7 females) undergoing 2DC had three, noncontrast, 3D apical volumes acquired at rest. Images were fused using an automated image fusion approach. Quality of the 3DFE was compared to both 3D and 2DC based on contrast-to-noise ratio (CNR) and endocardial border definition. We then compared clinical wall-motion score index (WMSI) calculated from 3DFE and 3D to those obtained from 2DC images. Fused 3D volumes had significantly improved CNR (8.92 ± 1.35 vs. 6.59 ± 1.19, P echocardiography (1.06 ± 0.09 vs. 1.07 ± 0.15, P = 0.69), whereas unfused images produced significantly more variable results (1.19 ± 0.30). This was confirmed by a better intraclass correlation coefficient (ICC 0.72; 95% CI 0.32-0.88) relative to comparisons with unfused images (ICC 0.56; 95% CI 0.02-0.81). 3DFE significantly improves left ventricular image quality compared to unfused 3D in a patient population and allows noncontrast assessment of wall motion that approaches that achieved with 2D contrast echocardiography. © 2014, Wiley Periodicals, Inc.

Comparison of left ventricular outflow geometry and aortic valve area in patients with aortic stenosis by 2-dimensional versus 3-dimensional echocardiography.

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Saitoh, Takeji; Shiota, Maiko; Izumo, Masaki; Gurudevan, Swaminatha V; Tolstrup, Kirsten; Siegel, Robert J; Shiota, Takahiro

2012-06-01

The present study sought to elucidate the geometry of the left ventricular outflow tract (LVOT) in patients with aortic stenosis and its effect on the accuracy of the continuity equation-based aortic valve area (AVA) estimation. Real-time 3-dimensional transesophageal echocardiography (RT3D-TEE) provides high-resolution images of LVOT in patients with aortic stenosis. Thus, AVA is derived reliably with the continuity equation. Forty patients with aortic stenosis who underwent 2-dimensional transthoracic echocardiography (2D-TTE), 2-dimensional transesophageal echocardiography (2D-TEE), and RT3D-TEE were studied. In 2D-TTE and 2D-TEE, the LVOT areas were calculated as π × (LVOT dimension/2)(2). In RT3D-TEE, the LVOT areas and ellipticity ([diameter of the anteroposterior axis]/[diameter of the medial-lateral axis]) were evaluated by planimetry. The AVA is then determined using planimetry and the continuity equation method. LVOT shape was found to be elliptical (ellipticity of 0.80 ± 0.08). Accordingly, the LVOT areas measured by 2D-TTE (median 3.7 cm(2), interquartile range 3.1 to 4.1) and 2D-TEE (median 3.7 cm(2), interquartile range 3.1 to 4.0) were smaller than those by 3D-TEE (median 4.6 cm(2), interquartile range 3.9 to 5.3; p interquartile range 0.79 to 1.3, p interquartile range 0.64 to 0.94) and 2D-TEE (median 0.76 cm(2), interquartile range 0.62 to 0.95). Additionally, the continuity equation-based AVA by RT3D-TEE was consistent with the planimetry method. In conclusion, RT3D-TEE might allow more accurate evaluation of the elliptical LVOT geometry and continuity equation-based AVA in patients with aortic stenosis than 2D-TTE and 2D-TEE. Copyright © 2012 Elsevier Inc. All rights reserved.

Recent advances in echocardiography for nuclear medicine physician

International Nuclear Information System (INIS)

Hong, Geu Ru; Shin, Dong Gu

2005-01-01

Echocardiography is one of the most frequently used techniques for diagnosing cardiovascular diseases. Over the last twenty years, technological advances have enabled the application of high-quality imaging. Important recent developments have occurred in echocardiography that are already being used clinically. Equipment and hardware is now available to produce real time three-dimensional and contrast enhanced imaging. Tissue Doppler and stress echocardiography have provided potential benefit to analyze hemodynamic information of heart. This review discusses each of these new developments and their potential impact on the practice of echocardiography and cardiology in general

111In-labeled platelet scintigraphy and two-dimensional echocardiography for detection of left atrial appendage thrombi. Studies in a new canine model

International Nuclear Information System (INIS)

Vandenberg, B.F.; Seabold, J.E.; Conrad, G.R.; Kieso, R.; Johnson, J.; Fox-Eastham, K.; Ponto, J.; Bruch, P.; Kerber, R.E.

1988-01-01

111In-labeled platelet scintigraphy and two-dimensional echocardiography were performed in 40 dogs to determine the ability of the two techniques to detect left atrial appendage thrombi. Thrombi were induced in 33 dogs that were classified into two groups, acute or chronic, according to the time of labeled-platelet injection after thrombus induction. In the acute group (17 dogs), platelets were injected 24 hours after thrombus induction. In the chronic group (16 dogs), platelets were injected 4-8 days after thrombus induction. Sham thoracotomies were performed on seven additional control dogs who did not receive thrombin injections. Analog and blood pool-corrected 111In-labeled platelet scintigraphy images were obtained 4-72 hours later. Closed-chest two-dimensional echocardiography was performed before thoracotomy and repeated at the time of scintigraphy. The location and size of each thrombus were verified at autopsy. Two-dimensional echocardiography detected three of 17 acute (mean volume, 1.2 +/- 1.0 cc) and three of 10 chronic (mean volume, 0.4 +/- 0.3 cc; p less than 0.025) left atrial appendage thrombi. 111In-labeled platelet scintigraphy detected all 17 acute thrombi but only two of 10 chronic thrombi. The measured radioactivity levels of the excised thrombi were 1,949 +/- 1,665 cpm/clot/dose in group 1 and 228 +/- 213 cpm/clot/dose in group 2 (p less than 0.005). In this model, 111In-labeled platelet scintigraphy was able to detect acute left atrial appendage thrombi that could not be identified by two-dimensional echocardiography. Both techniques showed poor sensitivity for detection of chronic thrombi. The decline in sensitivity of 111In-labeled platelet scintigraphy for detection of older thrombi is probably due to diminished labeled-platelet incorporation

Extended supersymmetry in four-dimensional Euclidean space

International Nuclear Information System (INIS)

McKeon, D.G.C.; Sherry, T.N.

2000-01-01

Since the generators of the two SU(2) groups which comprise SO(4) are not Hermitian conjugates of each other, the simplest supersymmetry algebra in four-dimensional Euclidean space more closely resembles the N=2 than the N=1 supersymmetry algebra in four-dimensional Minkowski space. An extended supersymmetry algebra in four-dimensional Euclidean space is considered in this paper; its structure resembles that of N=4 supersymmetry in four-dimensional Minkowski space. The relationship of this algebra to the algebra found by dimensionally reducing the N=1 supersymmetry algebra in ten-dimensional Euclidean space to four-dimensional Euclidean space is examined. The dimensional reduction of N=1 super Yang-Mills theory in ten-dimensional Minkowski space to four-dimensional Euclidean space is also considered

Does three-dimensional transesophageal echocardiography provide incremental value in percutaneous closure of ascending aortic pseudoaneurysm?

Science.gov (United States)

Elkaryoni, Ahmed; Hsiung, Ming C; Arisha, Mohammed J; Ahmad, Amier; Nanda, Navin C; Mohamed, Ahmed H; Attia, Doaa; Sachdeva, Ankush; Singh, Lovepreet; Yin, Wei-Hsian

2017-07-01

Ascending aortic pseudoaneurysms (AO PSAs), if left untreated, are complicated by a high rate of rupture resulting in significant morbidity and mortality. New transcatheter modalities have emerged as acceptable surgical alternatives for their management. We present a case of an ascending aortic PSA in which intraoperative two- and three-dimensional transesophageal echocardiography (2DTEE and 3DTEE) provided a comprehensive assessment of the PSA in pre- and postclosure settings. © 2017, Wiley Periodicals, Inc.

Clinical assessment of heart chamber size and valve motion during cardiopulmonary resuscitation by two-dimensional echocardiography.

Science.gov (United States)

Rich, S; Wix, H L; Shapiro, E P

1981-09-01

It has been generally accepted that enhanced blood flow during closed-chest CPR is generated from compression of the heart between the sternum and the spine. To visualize the heart during closed-chest massage, we performed two-dimensional echocardiography (2DE) during resuscitation efforts in four patients who had cardiac arrest. 2DE analysis showed that (1) the LV internal dimensions did not change appreciably with chest compression; (2) the mitral and aortic valves were open simultaneously during the compression phase; (3) blood flow into the right heart, as evidenced by saline bubble contrast, occurred during the relaxation phase; and (4) compression of the right ventricle and LA occurred in varying amounts in all patients. We conclude that stroke volume from the heart during CPR does not result from compression of the LV. Rather, CPR-induced improved cardiocirculatory dynamics appear to be principally the result of changes in intrathoracic pressure created by sternal compression.

Real-time three dimensional transesophageal echocardiography: technical aspects and clinical applications

Directory of Open Access Journals (Sweden)

Sergio Mondillo

2010-02-01

Full Text Available Real-time three-dimensional transeso-phageal echocardiography (RT3DTEE is now commonly used in daily clinical practice. The transesophageal, compared to the transthoracic approach, allows the visualization of the whole spectrum of the mitral valve apparatus and the posterior cardiac structures. Moreover, images obtained by RT 3D TEE provide a unique and complete visualization of the mitral valve prosthetic elements. Indeed, the possibility to visualize guidewires and catheters in cardiac chambers and their relationship with cardiac structures during percutaneous transcatheter procedures reduces the time of radiation exposure and simplifies the approach becoming the reference method for monitoring. This review aims to underline the potential clinical applications and the advantages of RT3DTEE compared to other methods.

3D Harmonic Echocardiography:

NARCIS (Netherlands)

M.M. Voormolen (Marco)

2007-01-01

textabstractThree dimensional (3D) echocardiography has recently developed from an experimental technique in the ’90 towards an imaging modality for the daily clinical practice. This dissertation describes the considerations, implementation, validation and clinical application of a unique

Transesophageal echocardiography. 3. rev. and enl. ed.

International Nuclear Information System (INIS)

Lambertz, Heinz; Lethen, Harald

2013-01-01

The book on transesophageal echocardiography covers the following issues: Development of transesophageal echocardiography, technical advances; indications and contraindication for transesophageal echocardiography; systematic of the medical examination process; cardiac valves and valve prostheses; mitral and aortic valvuloplasty, TAVI and interventional treatment of mitral regurgitation; infectious endocarditis; one-way and effluence disturbances of the left and right ventricle; diseases of the thoracic aorta; undefined right ventricle enlargement; lung embolism, acute infarct complications; TEE during anesthesia and perioperative intensive medicine, cardiac sources of embolism; cardiac tumors, mediastinal lymph nodes; pericardiac diseases; congenital heart diseases in childhood and adulthood; catheter interventions and heart valve reconstruction; surgically corrected congenital cardiac defects; intracavitary versus transesophageal echocardiography; three-dimensional TEE; coronary diagnostics; ischemia and vitality diagnostics.

Use of real time three-dimensional transesophageal echocardiography in intracardiac catheter based interventions.

Science.gov (United States)

Perk, Gila; Lang, Roberto M; Garcia-Fernandez, Miguel Angel; Lodato, Joe; Sugeng, Lissa; Lopez, John; Knight, Brad P; Messika-Zeitoun, David; Shah, Sanjiv; Slater, James; Brochet, Eric; Varkey, Mathew; Hijazi, Ziyad; Marino, Nino; Ruiz, Carlos; Kronzon, Itzhak

2009-08-01

Real-time three-dimensional (RT3D) echocardiography is a recently developed technique that is being increasingly used in echocardiography laboratories. Over the past several years, improvements in transducer technologies have allowed development of a full matrix-array transducer that allows acquisition of pyramidal-shaped data sets. These data sets can be processed online and offline to allow accurate evaluation of cardiac structures, volumes, and mass. More recently, a transesophageal transducer with RT3D capabilities has been developed. This allows acquisition of high-quality RT3D images on transesophageal echocardiography (TEE). Percutaneous catheter-based procedures have gained growing acceptance in the cardiac procedural armamentarium. Advances in technology and technical skills allow increasingly complex procedures to be performed using a catheter-based approach, thus obviating the need for open-heart surgery. The authors used RT3D TEE to guide 72 catheter-based cardiac interventions. The procedures included the occlusion of atrial septal defects or patent foramen ovales (n=25), percutaneous mitral valve repair (e-valve clipping; n=3), mitral balloon valvuloplasty for mitral stenosis (n=10), left atrial appendage obliteration (n=11), left atrial or pulmonary vein ablation for atrial fibrillation (n=5), percutaneous closures of prosthetic valve dehiscence (n=10), percutaneous aortic valve replacement (n=6), and percutaneous closures of ventricular septal defects (n=2). In this review, the authors describe their experience with this technique, the added value over multiplanar two-dimensional TEE, and the pitfalls that were encountered. The main advantages found for the use RT3D TEE during catheter-based interventions were (1) the ability to visualize the entire lengths of intracardiac catheters, including the tips of all catheters and the balloons or devices they carry, along with a clear depiction of their positions in relation to other cardiac structures, and

Fetal echocardiography

International Nuclear Information System (INIS)

Chaubal, Nitin G.; Chaubal, Jyoti

2009-01-01

USG performed with a high-end machine, using a good cine-loop facility is extremely helpful in the diagnosis of fetal cardiac anomalies. In fetal echocardiography, the four-chamber view and the outflow-tract view are used to diagnose cardiac anomalies. The most important objective during a targeted anomaly scan is to identify those cases that need a dedicated fetal echocardiogram. Associated truncal and chromosomal anomalies need to be identified. This review shows how fetal echocardiography, apart from identifying structural defects in the fetal heart, can be used to look at rhythm abnormalities and other functional aspects of the fetal heart

Two dimensional echocardiography in mitral, aortic and tricuspid valve prolapse - The clinical problem, cardiac nuclear imaging considerations and a proposed standard for diagnosis

International Nuclear Information System (INIS)

Morganroth, J.; Jones, R.H.; Chen, C.C.; Naito, M.; Thomas Jefferson University, Philadelphia, Pa.; Duke University, Medical Center, Durham, N.C.)

1980-01-01

The mitral valve prolapse syndrome may present with a variety of clinical manifestations and has proved to be a common cause of nonspecific cardiac symptoms in clinical practice. Primary and secondary forms must be distinguished. Myxomatous degeneration appears to be the common denominator of the primary form. The diagnostic standard of this form has not previously been defined because the detection of mitral leaflet tissue in the left atrium (prolapse) on physical examination or angiography is nonspecific. M mode echocardiography has greatly enhanced the recognition of this syndrome but has not proved to be the best diagnostic standard because of its limited view of mitral valve motion. The advent of two-dimensional echocardiography has provided the potential means for specific identification of the mitral leaflet motion in systole and can be considered the diagnostic standard for this syndrome. Primary myxomatous degeneration with leaflet prolapse is not localized to the mitral valve. Two-dimensional echocardiography has detected in preliminary studies tricuspid valve prolapse in up to 50% and aortic valve prolapse in about 20% of patients with idiopathic mitral valve prolapse

Assessment of atrial fibrillation and vulnerability in patients with Wolff-Parkinson-White syndrome using two-dimensional speckle tracking echocardiography.

Directory of Open Access Journals (Sweden)

Jing-Jie Li

Full Text Available PURPOSE: The aim was to assess atrial fibrillation (AF and vulnerability in Wolff-Parkinson-White (WPW syndrome patients using two-dimensional speckle tracking echocardiography (2D-STE. METHODS: All patients were examined via transthoracic echocardiography and 2D-STE in order to assess atrial function 7 days before and 10 days after RF catheter ablation. A postoperative 3-month follow-up was performed via outpatient visit or telephone calls. RESULTS: Results showed significant differences in both body mass index (BMI and supraventricular tachycardia (SVT duration between WPW patients and DAVNP patients (both P<0.05. Echocardiography revealed that the maximum left atrial volume (LAVmax and the left ventricular mass index (LVMI in diastole increased noticeably in patients with WPW compared to patients with DAVNP both before and after ablation (all P<0.05. Before ablation, there were obvious differences in the levels of SRs, SRe, and SRa from the 4-chamber view (LA in the WPW patients group compared with patients in the DAVNP group (all P<0.05. In the AF group, there were significant differences in the levels of systolic strain rate (SRs, early diastolic strain rate (SRe, and late diastolic strain rate (SRa from the 4-chamber view (LA both before and after ablation (all P<0.05. In the non-AF group, there were decreased SRe levels from the 4-chamber view (LA/RA pre-ablation compared to post-ablation (all P<0.05. CONCLUSION: Our findings provide convincing evidence that WPW syndrome may result in increased atrial vulnerability and contribute to the development of AF. Further, RF catheter ablation of AAV pathway can potentially improve atrial function in WPW syndrome patients. Two-dimensional speckle tracking echocardiography imaging in WPW patients would be necessary in the evaluation and improvement of the overall function of RF catheter ablation in a long-term follow-up period.

Cardiac MR imaging: Comparison with echocardiography and dynamic CT

International Nuclear Information System (INIS)

Colletti, P.M.; Norris, S.; Raval, J.; Boswell, W.; Lee, K.; Ralls, P.; Haywood, J.; Halls, J.

1986-01-01

The authors compared gated cardiac MR imaging with two-dimensional and Doppler echocardiography and dynamic CT. Gated cardiac MR imaging (VISTA unit, 0.5 T) was performed in 55 patients with a variety of conditions. Accuracy of diagnosis was compared. CT showed arterial, valvular, and pericardial calcifications not seen on MR imaging. Many lesions were seen as well on CT as on MR imaging. Two-dimensional echocardiography was superior in demonstrating wall motion and valvular disease. MR imaging was superior in demonstrating myocardial structures

Three-dimensional Speckle Tracking Echocardiography in Light Chain Cardiac Amyloidosis: Examination of Left and Right Ventricular Myocardial Mechanics Parameters.

Science.gov (United States)

Urbano-Moral, Jose Angel; Gangadharamurthy, Dakshin; Comenzo, Raymond L; Pandian, Natesa G; Patel, Ayan R

2015-08-01

The study of myocardial mechanics has a potential role in the detection of cardiac involvement in patients with amyloidosis. This study aimed to characterize 3-dimensional-speckle tracking echocardiography-derived left and right ventricular myocardial mechanics in light chain amyloidosis and examine their relationship with brain natriuretic peptide. In patients with light chain amyloidosis, left ventricular longitudinal and circumferential strain (n=40), and right ventricular longitudinal strain and radial displacement (n=26) were obtained by 3-dimensional-speckle tracking echocardiography. Brain natriuretic peptide levels were determined. All myocardial mechanics measurements showed differences when compared by brain natriuretic peptide level tertiles. Left and right ventricular longitudinal strain were highly correlated (r=0.95, P<.001). Left ventricular longitudinal and circumferential strain were reduced in patients with cardiac involvement (-9±4 vs -16±2; P<.001, and -24±6 vs -29±4; P=.01, respectively), with the most prominent impairment at the basal segments. Right ventricular longitudinal strain and radial displacement were diminished in patients with cardiac involvement (-9±3 vs -17±3; P<.001, and 2.7±0.8 vs 3.8±0.3; P=.002). On multivariate analysis, left ventricular longitudinal strain was associated with the presence of cardiac involvement (odds ratio = 1.6; 95% confidence interval, 1.04 to 2.37; P=.03) independent of the presence of brain natriuretic peptide and troponin I criteria for cardiac amyloidosis. Three-dimensional-speckle tracking echocardiography-derived left and right ventricular myocardial mechanics are increasingly altered as brain natriuretic peptide increases in light chain amyloidosis. There appears to be a strong association between left ventricular longitudinal strain and cardiac involvement, beyond biomarkers such as brain natriuretic peptide and troponin I. Copyright © 2015 Sociedad Española de Cardiología. Published by

On four dimensional mirror symmetry

International Nuclear Information System (INIS)

Losev, A.; Nekrasov, N.; Shatashvili, S.

2000-01-01

A conjecture relating instanton calculus in four dimensional supersymmetric theories and the deformation theory of Lagrangian submanifolds in C 2r invariant under a (subgroup of) Sp(2r,Z) is formulated. This is a four dimensional counterpart of the mirror symmetry of topological strings (relating Gromov-Witten invariants and generalized variations of Hodge structure). (orig.)

Incremental benefit of three-dimensional transesophageal echocardiography in the assessment of left main coronary artery stent protrusion.

Science.gov (United States)

Arisha, Mohammed J; Hsiung, Ming C; Ahmad, Amier; Nanda, Navin C; Elkaryoni, Ahmed; Mohamed, Ahmed H; Yin, Wei-Hsian

2017-06-01

Ostial lesions represent a challenging clinical scenario and percutaneous intervention (PCI) of left main coronary artery ostial lesions has been associated with postintervention complications, including protrusion of deployed stents into a sinus of Valsalva or aortic root. We report a case of stent protrusion into the aortic root following aorto-ostial left main coronary artery PCI, in which three-dimensional transesophageal echocardiography (3DTEE) provided incremental benefit over standard two-dimensional images. Specifically, 3DTEE confirmed the presence of stent protrusion by allowing clear visualization of the stent scaffold, in addition to characterizing the relationship between the stent and surrounding structures. © 2017, Wiley Periodicals, Inc.

Three dimensional transesophageal echocardiography guided transcatheter closure of mitral paraprosthesis regurgitation – A case report

Directory of Open Access Journals (Sweden)

Vinay Kumar Sharma

2013-05-01

Full Text Available The last two decades have witnessed vast advances in the field of cardiac intervention, particularly with regard to nonsurgical closure of structural heart diseases including para prosthetic valvular leaks. The use of imaging techniques to guide even well-established procedures enhances the efficiency and safety of these procedures. The present case report aims to highlight the role of three dimensional transesophageal echocardiography in pre, intra and post operative management of patients with mitral para prosthetic valvular regurgitation.

Echocardiography in patients with complications related to pacemakers and cardiac defibrillators.

Science.gov (United States)

Almomani, Ahmed; Siddiqui, Khadija; Ahmad, Masood

2014-03-01

The evolving indications and uses for implantable cardiac devices have led to a significant increase in the number of implanted devices each year. Implantation of endocardial leads for permanent pacemakers and cardiac defibrillators can cause many delayed complications. Complications may be mechanical and related to the interaction of the device leads with the valves and endomyocardium, e.g., perforation, infection, and thrombosis, or due to the electrical pacing of the myocardium and conduction abnormalities, e.g., left ventricular dyssynchrony. Tricuspid regurgitation, another delayed complication in these patients, may be secondary to both mechanical and pacing effects of the device leads. Echocardiography plays an important role in the diagnosis of these device-related complications. Both two-dimensional transthoracic echocardiography and transesophageal echocardiography provide useful diagnostic information. Real time three-dimensional echocardiography is a novel technique that can further enhance the detection of lead-related complications. © 2013, Wiley Periodicals, Inc.

Intracardiac echocardiography: use during transcatheter device closure of a patent ductus arteriosus in a dog.

Science.gov (United States)

Chetboul, V; Damoiseaux, C; Behr, L; Morlet, A; Moise, N S; Gouni, V; Lavennes, M; Pouchelon, J-L; Laborde, F; Borenstein, N

2017-06-01

Intracardiac echocardiography (ICE) is used in humans for percutaneous interventional procedures, such as transcatheter device closures. Intracardiac echocardiography provides high-resolution imaging of cardiac structures with two-dimensional, M-mode, Doppler, and also three-dimensional modalities. The present report describes application of ICE during transcatheter occlusion of patent ductus arteriosus using a canine ductal occluder in a dog for which transesophageal echocardiography could not provide an optimal acoustic window. Copyright © 2017 Elsevier B.V. All rights reserved.

Two-dimensional speckle tracking echocardiography demonstrates no effect of active acromegaly on left ventricular strain.

Science.gov (United States)

Volschan, I C M; Kasuki, L; Silva, C M S; Alcantara, M L; Saraiva, R M; Xavier, S S; Gadelha, M R

2017-06-01

Speckle tracking echocardiography (STE) allows for the study of myocardial strain (ε), a marker of early and subclinical ventricular systolic dysfunction. Cardiac disease may be present in patients with acromegaly; however, STE has never been used to evaluate these patients. To evaluate left ventricular (LV) global longitudinal strain in patients with active acromegaly with normal LV systolic function. Cross-sectional clinical study. Patients with active acromegaly with no detectable heart disease and a control group were matched for age, gender, arterial hypertension and diabetes mellitus underwent STE. Global LV longitudinal ε (GLS), left ventricular mass index (LVMi), left ventricular ejection fraction (LVEF) and relative wall thickness (RWT) were obtained via two-dimensional (2D) echocardiography using STE. Thirty-seven patients with active acromegaly (mean age 45.6 ± 13.8; 48.6% were males) and 48 controls were included. The mean GLS was not significantly different between the acromegaly group and the control group (in %, -20.1 ± 3.1 vs. -19.4 ± 2.2, p = 0.256). Mean LVMi was increased in the acromegaly group (in g/m 2 , 101.6 ± 27.1 vs. 73.2 ± 18.6, p Acromegaly patients, despite presenting with a higher LVMi when analyzed by 2D echocardiography, did not present with impairment in the strain when compared to a control group; this finding indicates a low chance of evolution to systolic dysfunction and agrees with recent studies that show a lower frequency of cardiac disease in these patients.

Diagnosis of the prosthetic heart valve pannus formation with real-time three-dimensional transoesophageal echocardiography.

Science.gov (United States)

Ozkan, Mehmet; Gündüz, Sabahattin; Yildiz, Mustafa; Duran, Nilüfer Eksi

2010-05-01

Prosthetic heart valve obstruction (PHVO) caused by pannus formation is an uncommon but serious complication. Although two-dimensional transesophageal echocardiography (2D-TEE) is the method of choice in the evaluation of PHVO, visualization of pannus is almost impossible with 2D-TEE. While demonstrating the precise aetiology of PHVO is essential for guiding the therapy, either thrombolysis for valve thrombosis or surgery for pannus formation, more sophisticated imaging techniques are needed in patients with suspected pannus formation. We present real-time 3D-TEE imaging in a patient with mechanical mitral PHVO, clearly demonstrating pannus overgrowth.

Obstructed bi-leaflet prosthetic mitral valve imaging with real-time three-dimensional transesophageal echocardiography.

Science.gov (United States)

Shimbo, Mai; Watanabe, Hiroyuki; Kimura, Shunsuke; Terada, Mai; Iino, Takako; Iino, Kenji; Ito, Hiroshi

2015-01-01

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) can provide unique visualization and better understanding of the relationship among cardiac structures. Here, we report the case of an 85-year-old woman with an obstructed mitral prosthetic valve diagnosed promptly by RT3D-TEE, which clearly showed a leaflet stuck in the closed position. The opening and closing angles of the valve leaflets measured by RT3D-TEE were compatible with those measured by fluoroscopy. Moreover, RT3D-TEE revealed, in the ring of the prosthetic valve, thrombi that were not visible on fluoroscopy. RT3D-TEE might be a valuable diagnostic technique for prosthetic mitral valve thrombosis. © 2014 Wiley Periodicals, Inc.

Novel techniques in stress echocardiography: a focus on the advantages and disadvantages.

Science.gov (United States)

Vamvakidou, Anastasia; Gurunathan, Sothinathan; Senior, Roxy

2016-01-01

Stress echocardiography (SE) is an established tool not only for the assessment of coronary artery disease (CAD), but also for the evaluation of valvular disease and cardiomyopathy. New techniques, namely contrast echocardiography for function and perfusion including assessment of coronary flow reserve, strain imaging, 3-dimensional echocardiography, Doppler-derived coronary flow reserve and multimodality echocardiography, have been incorporated into stress protocols for improving assessment of cardiac disease. In this review, the advantages and disadvantages of these novel SE techniques are examined in terms of feasibility, accuracy, reproducibility and applications.

Inverse Operation of Four-dimensional Vector Matrix

OpenAIRE

H J Bao; A J Sang; H X Chen

2011-01-01

This is a new series of study to define and prove multidimensional vector matrix mathematics, which includes four-dimensional vector matrix determinant, four-dimensional vector matrix inverse and related properties. There are innovative concepts of multi-dimensional vector matrix mathematics created by authors with numerous applications in engineering, math, video conferencing, 3D TV, and other fields.

Simulation for transthoracic echocardiography of aortic valve

Science.gov (United States)

Nanda, Navin C.; Kapur, K. K.; Kapoor, Poonam Malhotra

2016-01-01

Simulation allows interactive transthoracic echocardiography (TTE) learning using a virtual three-dimensional model of the heart and may aid in the acquisition of the cognitive and technical skills needed to perform TTE. The ability to link probe manipulation, cardiac anatomy, and echocardiographic images using a simulator has been shown to be an effective model for training anesthesiology residents in transesophageal echocardiography. A proposed alternative to real-time reality patient-based learning is simulation-based training that allows anesthesiologists to learn complex concepts and procedures, especially for specific structures such as aortic valve. PMID:27397455

Role of Three-Dimensional Speckle Tracking Echocardiography in the Quantification of Myocardial Iron Overload in Patients with Beta-Thalassemia Major.

Science.gov (United States)

Li, Shu-Juan; Hwang, Yu-Yan; Ha, Shau-Yin; Chan, Godfrey C F; Mok, Amanda S P; Wong, Sophia J; Cheung, Yiu-Fai

2016-09-01

The new three-dimensional speckle tracking echocardiography (3DSTE) may enable comprehensive quantification of global left ventricular (LV) myocardial mechanics. Twenty-four patients aged 29.3 ± 5.2 years and 22 controls were studied. 3DSTE was performed to assess LV 3D global strain, twist and torsion, ejection fraction, and systolic dyssynchrony index (SDI). The LV SDI was calculated as % of SD of times-to-peak strain of 16 segments/RR interval. The global performance index (GPI) was calculated as (global 3D strain·torsion)/SDI. Area under the receiver operating characteristic curve (AUC) was calculated to determine the capability of 3DSTE parameters to discriminate between patients with (cardiac magnetic resonance T2* overload. Compared with controls, patients had significantly lower LV global 3D strain (P overload. The LV composite index of strain, torsion, and dyssynchrony derived from 3DSTE enables sensitive detection of myocardial iron overload in patients with thalassemia. © 2016, Wiley Periodicals, Inc.

A Four-Dimensional Approach

African Journals Online (AJOL)

... of East Asian Students in English-speaking Countries: A Four-Dimensional ... country's language greatly shapes all aspects of the student's international education ... Taking this ecological approach will help clearly define the role that home ...

Super integrable four-dimensional autonomous mappings

International Nuclear Information System (INIS)

Capel, H W; Sahadevan, R; Rajakumar, S

2007-01-01

A systematic investigation of the complete integrability of a fourth-order autonomous difference equation of the type w(n + 4) = w(n)F(w(n + 1), w(n + 2), w(n + 3)) is presented. We identify seven distinct families of four-dimensional mappings which are super integrable and have three (independent) integrals via a duality relation as introduced in a recent paper by Quispel, Capel and Roberts (2005 J. Phys. A: Math. Gen. 38 3965-80). It is observed that these seven families can be related to the four-dimensional symplectic mappings with two integrals including all the four-dimensional periodic reductions of the integrable double-discrete modified Korteweg-deVries and sine-Gordon equations treated in an earlier paper by two of us (Capel and Sahadevan 2001 Physica A 289 86-106)

Echocardiography and cardiac resynchronisation therapy, friends or foes?

Science.gov (United States)

van Everdingen, W M; Schipper, J C; van 't Sant, J; Ramdat Misier, K; Meine, M; Cramer, M J

2016-01-01

Echocardiography is used in cardiac resynchronisation therapy (CRT) to assess cardiac function, and in particular left ventricular (LV) volumetric status, and prediction of response. Despite its widespread applicability, LV volumes determined by echocardiography have inherent measurement errors, interobserver and intraobserver variability, and discrepancies with the gold standard magnetic resonance imaging. Echocardiographic predictors of CRT response are based on mechanical dyssynchrony. However, parameters are mainly tested in single-centre studies or lack feasibility. Speckle tracking echocardiography can guide LV lead placement, improving volumetric response and clinical outcome by guiding lead positioning towards the latest contracting segment. Results on optimisation of CRT device settings using echocardiographic indices have so far been rather disappointing, as results suffer from noise. Defining response by echocardiography seems valid, although re-assessment after 6 months is advisable, as patients can show both continuous improvement as well as deterioration after the initial response. Three-dimensional echocardiography is interesting for future implications, as it can determine volume, dyssynchrony and viability in a single recording, although image quality needs to be adequate. Deformation patterns from the septum and the derived parameters are promising, although validation in a multicentre trial is required. We conclude that echocardiography has a pivotal role in CRT, although clinicians should know its shortcomings.

Gated 99mTc-MIBI single-photon emission computed tomography for the evaluation of left ventricular ejection fraction. Comparison with three-dimensional echocardiography

International Nuclear Information System (INIS)

Lipiec, P.; Wejner-Mik, P.; Krzeminska-Pakula, M.; Kapusta, A.; Kasprzak, J.D.; Kusmierek, J.; Plachcinska, A.; Szuminski, R.

2008-01-01

Parameters of left ventricular systolic function directly influence the management of patients with suspected coronary artery disease (CAD). Quantitative gated single-photon emission computed tomography (QGS; Cedars-Sinai Medical Center, Los Angeles, CA, USA) allows the computation of left ventricular ejection fraction (LVEF) from myocardial perfusion imaging studies which are frequently performed on patients with suspected CAD. Three-dimensional (3D) echocardiography is considered to be the echocardiographic ''gold standard'' for the quantification of LVEF. We sought to compare QGS with 3D echocardiography in the evaluation of EF in patients with suspected CAD. Ninety-one consecutive patients with suspected CAD, scheduled for coronary angiography, underwent rest electrocardiographic-gated technetium-99m methoxyisobutylisonitrile SPECT (G-SPECT) with measurement of LVEF by QGS and transthoracic 3D echocardiography with off-line measurement of LVEF (Tomtec 4D LV Analysis 1.1). The diagnosis of CAD was based on coronary angiography, performed on every patient. Nine patients were excluded from the analysis owing to unsuitability for 3D echocardiography (8 patients) or G-SPECT (1 patient). In the remaining group of 82 patients, 71 (87%) had significant CAD, 34 (42%) had a history of myocardial infarction, and 50 (61%) had perfusion defects at rest G-SPECT images. The mean LVEF measured by QGS and 3D echocardiography was 53±13% and 53±10%, respectively. The mean difference in LVEF between 3D echocardiography and QGS was 0.1±6.0% (P=0.87), and the correlation between the values obtained by both methods was high (r=0.88, P< 0.001). The largest discrepancies were observed in patients with small ventricular volumes. In patients undergoing diagnostic work-up for CAD, the measurement of LVEF by QGS algorithm provides high correlation and satisfactory agreement with the results of reference ultrasound method- 3D echocardiography. (author)

Normal left ventricular mechanics by two-dimensional speckle-tracking echocardiography. Reference values in healthy adults.

Science.gov (United States)

Kocabay, Gonenc; Muraru, Denisa; Peluso, Diletta; Cucchini, Umberto; Mihaila, Sorina; Padayattil-Jose, Seena; Gentian, Denas; Iliceto, Sabino; Vinereanu, Dragos; Badano, Luigi P

2014-08-01

Two-dimensional speckle-tracking echocardiography is a novel tool to assess myocardial function. The purpose of this study was to evaluate left ventricular myocardial strain and rotation parameters by two-dimensional speckle-tracking echocardiography in a large group of healthy adults across a wide age range to establish their reference values and to assess the influence of age, sex, and hemodynamic factors. Transthoracic echocardiograms were acquired in 247 healthy volunteers (139 women, 44 years [standard deviation, 16 years old] (range, 18-80 years). We measured longitudinal, circumferential, and radial peak systolic strain values, and left ventricular rotation and twist. Average values of global longitudinal, radial, and circumferential strain were -21.5% (standard deviation, 2.0%), 40.1% (standard deviation, 11.8%) and -22.2% (standard deviation, 3.4%), respectively. Longitudinal strain was significantly more negative in women, whereas radial and circumferential strain and rotational parameters were similar in both sexes. Accordingly, lower limits of normality for the strain components were -16.9% in men and -18.5% in women for longitudinal strain, and -15.4% for circumferential and 24.6% for radial strain, irrespective of sex. Longitudinal strain values were more negative at the base than at apical segments. Mean rotational values were -6.9° (standard deviation, 3.5°) for the base, 13.0° (standard deviation, 6.5°) for apical rotation, and 20.0° (standard deviation, 7.3°) for net twist. We report the comprehensive assessment of normal myocardial deformation and rotational mechanics in a large cohort of healthy volunteers. We found that women have more negative longitudinal strain, accounting for their higher left ventricular ejection fraction. Availability of reference values for these parameters may foster their implementation in the clinical routine. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

The advantages of live/real time three-dimensional transesophageal echocardiography during assessments of pulmonary stenosis.

Science.gov (United States)

Kemaloğlu Öz, Tuğba; Özpamuk Karadeniz, Fatma; Akyüz, Şükrü; Ünal Dayı, Şennur; Esen Zencirci, Aycan; Atasoy, Işıl; Ösken, Altuğ; Eren, Mehmet

2016-04-01

This report sought to compare live/real-time three-dimensional transesophageal echocardiography (3D-TEE) with two-dimensional transesophageal echocardiography (2D-TEE) and to determine whether there are advantages to using 3D-TEE on patients with pulmonary stenosis (PS). Sixteen consecutive adult patients (50 % male and 50 % female; mean age 33 ± 13.4 years) with PS and indications of TEE were prospectively enrolled in this study. Following this, initial 2D-TEE and 3D-TEE examinations were performed, and 3D-TEE images were analyzed using an off-line Q-lab software system. Finally, the 2D-TEE and 3D-TEE findings were compared. In the present study, 3D-TEE allowed us to obtain the en face views of pulmonary valves (PVs) in all but one patient. While this patient was without a PV due to a previous tetralogy of Fallot operation, we could detect the type of PV in the other 15 (93.7 %) patients by using 3D-TEE. Due to poor image quality, the most stenotic area was not measurable in only one (6.2 %) of the patients. In eight (50 %) of the patients, severity and localization of stenosis were more precisely determined with 3DTEE than with 2D-TEE. The PVs' maximal annulus dimensions were found to be significantly larger when they were measured using 3D modalities. This study provides evidence of the incremental value of using 3D-TEE rather than 2D-TEE during assessments of PS, specifically in cases where special conditions (pregnancy, pulmonary regurgitation, and concomitant atrial septal defects) cause recordings of the transvalvular peak gradient to be inaccurate. Therefore, 3D-TEE should be used as a complementary imaging tool to 2D-TEE during routine echocardiographic examinations.

Evaluation of left ventricular function and volumes in patients with ischaemic cardiomyopathy: gated single-photon emission computed tomography versus two-dimensional echocardiography

International Nuclear Information System (INIS)

Vourvouri, E.C.; Poldermans, D.; Sianos, G.; Sozzi, F.B.; Schinkel, A.F.L.; Sutter, J. de; Roelandt, J.R.T.C.; Bax, J.J.; Parcharidis, G.; Valkema, R.

2001-01-01

The objective of this study was to perform a head-to-head comparison between two-dimensional (2D) echocardiography and gated single-photon emission computed tomography (SPET) for the evaluation of left ventricular (LV) function and volumes in patients with severe ischaemic LV dysfunction. Thirty-two patients with chronic ischaemic LV dysfunction [mean LV ejection fraction (EF) 25%±6%] were studied with gated SPET and 2D echocardiography. Regional wall motion was evaluated by both modalities and scored by two independent observers using a 16-segment model with a 5-point scoring system (1= normokinesia, 2= mild hypokinesia, 3= severe hypokinesia, 4= akinesia and 5= dyskinesia). LVEF and LV end-diastolic and end-systolic volumes were evaluated by 2D echocardiography using the Simpson's biplane discs method. The same parameters were calculated using quantitative gated SPET software (QGS, Cedars-Sinai Medical Center). The overall agreement between the two imaging modalities for assessment of regional wall motion was 69%. The correlations between gated SPET and 2D echocardiography for the assessment of end-diastolic and end-systolic volumes were excellent (r=0.94, P<0.01, and r=0.96, P<0.01, respectively). The correlation for LVEF was also good (r=0.83, P<0.01). In conclusion: in patients with ischaemic cardiomyopathy, close and significant relations between gated SPET and 2D echocardiography were observed for the assessment of regional and global LV function and LV volumes; gated SPET has the advantage that it provides information on both LV function/dimensions and perfusion. (orig.)

Four-dimensional hilbert curves for R-trees

DEFF Research Database (Denmark)

Haverkort, Herman; Walderveen, Freek van

2011-01-01

Two-dimensional R-trees are a class of spatial index structures in which objects are arranged to enable fast window queries: report all objects that intersect a given query window. One of the most successful methods of arranging the objects in the index structure is based on sorting the objects...... according to the positions of their centers along a two-dimensional Hilbert space-filling curve. Alternatively, one may use the coordinates of the objects' bounding boxes to represent each object by a four-dimensional point, and sort these points along a four-dimensional Hilbert-type curve. In experiments...

Four-dimensional strings: Phenomenology and model building

International Nuclear Information System (INIS)

Quiros, M.

1989-01-01

In these lectures we will review some of the last developments in string theories leading to the construction of realistic four-dimensional string models. Special attention will be paid to world-sheet and space-time supersymmetry, modular invariance and model building for supersymmetric and (tachyon-free) nonsupersymmetric ten and four-dimensional models. (orig.)

Prosthetic mitral valve obstruction: role of real-time three-dimensional transesophageal echocardiography in diagnosis.

Science.gov (United States)

Kannan, Arun; Jahan, Kahroba; Lotun, Kapildeo; Janardhanan, Rajesh

2015-09-21

Acute prosthetic valve thrombosis is a potentially serious complication with an incidence as high as 6% per patient-year for prostheses in the mitral position. Accurate diagnosis of the degree of obstruction and differentiation of pannus versus thrombus is critical in determination of the best mode of therapy. We discuss a case of a patient with multiple comorbidities who presented with mechanical mitral valve obstruction where both transthoracic and two-dimensional transesophageal echocardiography (TEE) were limited in making an accurate diagnosis regarding the mechanism of obstruction. Real-time 3D-TEE (RT-3DTEE) was critical in identifying a partial thrombus on the mechanical valve and guided the choice of thrombolysis as the most appropriate intervention, thus avoiding high-risk surgery in this patient with significant multiple comorbidities. 2015 BMJ Publishing Group Ltd.

Kawasaki disease-associated coronary artery lesions with navigator echo-based. Respiratory-gated three dimensional coronary magnetic resonance angiography compared with echocardiography in young children

International Nuclear Information System (INIS)

Amino, Masayuki; Teraoka, Kunihiko; Hirano, Masaharu; Kawashima, Naoshi; Kakizaki, Dai; Ookubo, Yasuo; Sasaki, Kazuyoshi; Katuyama, Hiroaki

2004-01-01

Navigator echo-based respiratory-gated three dimensional coronary magnetic resonance angiography (3D-CMRA) was compared with echocardiography, to determine whether 3D-CMRA was useful for the evaluation of Kawasaki disease-associated coronary artery lesions. Sixteen consecutive patients (imaging was performed 17 times in total) who were given a diagnosis of Kawasaki's disease at the pediatric department of our hospital and examined for the precise examination of complicating coronary artery lesions on MRI using a navigator-echo technique because of their incapability of holding their breath during imaging were entered into the present study. A 1.5T MRI system was used. Gd-DOTA was given at a total volume of 0.1 mmol/kg. During imaging, CMRA visualized the left coronary arteries in all 17 cases and the right coronary arteries in 16 cases, but not in one case. The left main coronary trunk segment no.5 was demonstrated in all cases with CMRA, but not in 4 cases with echocardiography. The left anterior descending branch no.6 was visualized in 11 of the 17 cases with CMRA, but only in 5 cases with echocardiography. The left circumflex branch no.11 was observed in 6 cases with CMRA, but only in 2 cases with echocardiography. As for the right coronary arteries, branches no.1 and no.2 were observed in 16 and 9 cases with CMRA, respectively, and in 13 and 3 cases with echocardiography, respectively. Vascular diameters measured on CMRA were almost identical to those on echocardiography, within the range of arteries visualized. 3D-CMRA combined with a navigator echo technique appears to be a useful tool for the observation of coronary artery lesions associated with Kawasaki's disease because it is superior in lesion visualization to echocardiography. (author)

Imaging the heart: cardiac scintigraphy and echocardiography in US hospitals (1983)

International Nuclear Information System (INIS)

McPhee, S.J.; Garnick, D.W.

1986-01-01

The rapid growth of cardiac catheterization has raised questions about the availability of less costly, noninvasive tests such as cardiac scintigraphy and echocardiography. To assess their availability and rates of use, we surveyed 3778 non-federal short-term US hospitals in June, 1983. Overall, 2605 hospitals (69%) offered 201 Tl myocardial perfusion scans, 2580 (68%) 99mTc equilibrium gated blood pool scans, and 2483 (67%) cardiac shunt scans; 1679 hospitals (44%) offered M-mode and/or 2-dimensional echocardiography, and 768 (20%) pulsed Doppler echocardiography. Volumes of procedures varied enormously among hospitals capable of performing them. High volumes of both scintigraphy and echocardiography were performed in a small number of hospitals. Larger, voluntary, and teaching hospitals performed higher volumes of both procedures. Despite widespread availability of these noninvasive technologies, high volumes of both cardiac scintigraphy and echocardiography procedures are concentrated in a small number of US hospitals

The Value of Contrast Echocardiography

Directory of Open Access Journals (Sweden)

Shannon C. Treiber

2016-01-01

Full Text Available Purpose: There is much evidence-based research proving the effectiveness of contrast echocardiography, but there are still questions and concerns about its specific uses. This study tested the effectiveness of contrast echocardiography in defining the left ventricular endocardial border. Methods: From 30 patients, a total of 60 echocardiograms –– 30 with and 30 without use of contrast –– were retrospectively reviewed by four blinded cardiologists with advanced training in echocardiography. No single cardiologist reviewed contrast and noncontrast images of the same patient. Each set of 30 echocardiograms was then studied for wall-motion scoring. Visualization of left ventricular wall segments and a global visualization confidence level of interpretation were recorded. Results: Of all wall segments (N = 510, 91% were visualized in echocardiograms with use of contrast, whereas 75% of the walls were visualized in echocardiograms without contrast (P < 0.001. Of 30 examinations, 17 contrast echocardiograms were read with high confidence compared to 6 without contrast use (P = 0.004. The number of walls visualized with contrast was increased in 18 patients (60%, whereas noncontrast echocardiograms yielded more visualized walls in 6 patients (20%, P = 0.002. Conclusions: This study demonstrates that contrast is valuable to echocardiographic imaging. Its use should be supported throughout echocardiography clinics and encouraged in certain patients for whom resting and stress echocardiography results without contrast often prove uninterpretable.

Comparison of two-dimensional echocardiography with gated radionuclide ventriculography in the evaluation of global and regional left ventricular function in acute myocardial infarction

International Nuclear Information System (INIS)

Van Reet, R.E.; Quinones, M.A.; Poliner, L.R.; Nelson, J.G.; Waggoner, A.D.; Kanon, D.; Lubetkin, S.J.; Pratt, C.M.; Winters, W.L. Jr.

1984-01-01

Two-dimensional echocardiography and gated radionuclide ventriculography were performed in 93 patients (66 men, 27 women; mean age 61 years) with 95 episodes of acute myocardial infarction within 48 hours and at 10 days after infarction. Abnormal motion of an inferior or posterior wall segment was seen in 91% of inferoposterior infarctions by echocardiography versus 61% seen by radionuclide ventriculography. Ejection fractions determined by echocardiography and radionuclide ventriculography correlated well (r . 0.82) and did not change from the first 48 hours to 10 days after infarction (0.48 +/- 0.14). Similarly, wall motion score showed minimal change from the first 48 hours to 10 days. In-hospital mortality was 37 and 42% in patients with an ejection fraction of 0.35 or less by echocardiography and radionuclide ventriculography, respectively. No mortality was seen in patients with an ejection fraction above 0.40 by either test. The echocardiographic wall motion score was also predictive of mortality (40 versus 2%; score less than or equal to 0.50 versus greater than 0.50). The 1 year mortality rate in the 81 short-term survivors was 17%. Mortality was lowest in patients with an ejection fraction above 0.49 or wall motion score above (0.79 (2 to 5%) and worse in those with an ejection fraction below 0.36 or wall motion score below 0.51 (36 to 63%) by either technique. Thus in acute myocardial infarction, echocardiography and radionuclide ventriculography provide a comparable assessment of left ventricular function and wall motion in anterior infarction. Echocardiography appears more sensitive in detecting inferoposterior wall motion abnormalities. Both techniques are capable of identifying subgroups of patients with a high risk of death during the acute event and with an equally high mortality rate over a 1 year follow-up period

Comparison of Hyperemic Impedance Echocardiography with Dobutamine Stress Echocardiography to Detect Inducible Myocardial Ischemia: A Pilot Study.

Science.gov (United States)

Patel, Jijibhoy J; Gupta, Ankur; Nanda, Navin C

2016-03-01

Stress echocardiography using exercise or pharmacological stressors is either contraindicated or associated with significant side effects in some patients. This pilot study was designed to evaluate a new technique, hyperemic impedance echocardiography (HIE). It is based on reactive coronary hyperemia when transient limb ischemia is induced by tourniquet inflation. We hypothesized that this physiologic coronary hyperemia can identify inducible myocardial ischemia by assessment of regional wall motion abnormalities on echocardiography when compared with dobutamine stress echocardiography (DSE). Twenty consecutive outpatients with suspected stable coronary artery disease (CAD) who underwent clinically indicated DSE were recruited for performance of HIE after informed consent was obtained. Standard graded dobutamine infusion protocol from 5 to 40 μg/kg per min was used for DSE. HIE was performed by inflating tourniquets at a pressure of 10 mmHg below the systolic blood pressure for 1 minute in three of four extremities at a time for total of four cycles. Echocardiography was performed immediately after the last rotating tourniquet deflation. DSE and HIE were classified as abnormal for development of new or worsening wall motion abnormality in at least one myocardial segment. Test characteristics were also determined for a subset of these patients (n = 12) who underwent clinically indicated coronary angiography. Hyperemic impedance echocardiography showed 86% sensitivity, 67% specificity, 86% positive predictive value, and 67% negative predictive value with a test accuracy of 80% to detect inducible myocardial wall motion abnormalities when compared with DSE. HIE also showed 83% sensitivity, 75% negative predictive value with a test accuracy of 66.7% for detection of significant (≥50% diameter stenosis) CAD on coronary angiography. In this pilot study, HIE was a feasible, safe, and promising method for detection of inducible myocardial ischemia by assessment of

Recommendations for terminology and display for doppler echocardiography

International Nuclear Information System (INIS)

Anon.

1986-01-01

Doppler echocardiography has recently emerged as a major noninvasive technique with many applications in cardiology. To a large extent, this has been based upon a combination of clinical and engineering advances which now make possible the use of quantitative Doppler echocardiography in combination with two-dimensional imaging for measurement of volume flows, transvalve gradients, and other physiologic flow parameters which reflect cardiac function. It was the purpose of this Committee to provide a glossary of terms which could be used in standard fashion for papers and discussions related to Doppler echocardiography. As part of its task, the Committee also undertook an attempt to recommend a standard for display of Doppler information which would be useful, both for manufacturers and for clinicians. The document, therefore, includes: Section I, the Committee's recommendations for Doppler display. Section II, the glossary of Doppler terms, related to engineering and to clinical applications

Evaluation of left ventricular volumes in patients with congenital heart disease and abnormal left ventricular geometry. Comparison of MRI and transthoracic 3-dimensional echocardiography

International Nuclear Information System (INIS)

Gutberlet, M.; Grothoff, M.; Roettgen, R.; Lange, P.; Felix, R.; Abdul-Khaliq, H.; Schroeter, J.; Schmitt, B.; Vogel, M.

2003-01-01

Purpose: To assess the new method of 3-dimensional echocardiography in comparison to the 'gold standard' MRI as to its ability to calculate left ventricular volumes in patients with congenital heart disease. Materials and methods: Eighteen patients between the ages of 3.9 to 37.3 years (mean: 12.8±9.7) with a geometrically abnormal left ventricle were examined using a 1.5 T scanner with a fast gradient-echo sequence (TR=14 ms, TE=2.6-2.9 ms, FOV=300-400 mm, flip angle=20 , matrix=128:256, slice thickness=5 mm, retrospective gating) in multislice-multiphase technique. Transthoracic 3D-echocardiography was performed with a 3.5 MHz transducer and a Tomtec trademark (Munich, Germany) system for 3D reconstruction. Results: Volume calculation was possible in all patients with 3D-echocardiography, but the muscle mass calculation only succeeded in 11 to 18 patients (61%) due to inadequate visualization of the entire myocardium. Comparing MRI and 3D-echocardiography, the correlation was r=0.97 for the end-systolic volumes, r=0.98 for the end-diastolic volumes, r=0.79 for the end-systolic muscle mass and r=0.77 for the end-diastolic muscle mass. The agreement between both methods was considered good for the calculated end-diastolic volumes and sufficient for the calculated end-systolic volumes. The muscle mass calculations showed larger differences especially for the end-systolic mass. Mean intraobserver variability was 18.6% for end-systolic and 8.3% for end-diastolic volumes. Conclusion: In patients with an abnormal left ventricular configuration due to congenital heart disease, the new method of 3D-echocardiography is sufficient for volume calculations in preselected patients. The high intraobserver variability is still a limitation of transthoracic 3D-echocardiography in comparison to MRI. (orig.) [de

Evaluation of Subclinical Left Ventricular Systolic Dysfunction in Chronic Asymptomatic Alcoholics by Speckle Tracking Echocardiography

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Murathan Kucuk

2017-01-01

Full Text Available By using two-dimensional speckle tracking echocardiography, we aimed to investigate the structural and functional changes on myocardium in chronic asymptomatic alcoholics without any cardiovascular disease. Forty-one consecutive asymptomatic male alcoholics who were admitted to the outpatient alcoholism unit and 30 age matched healthy male volunteers selected as the control group were enrolled in the study. The study group were investigated by using standard two-dimensional echocardiography and speckle tracking echocardiography. The left ventricular (LV global longitudinal strain and LV global circumferential strain were significantly lower in alcoholics when compared with control subjects. There was no difference in global radial strain between the two groups. To demonstrate the effect of total life time dose of ethanol (TLDE on echocardiographic abnormalities, we assessed the correlation analysis. There was a nonsignificant weak correlation between global LV circumferential strain and TLDE (r=0.27, p=0.083. Speckle tracking echocardiography derived left ventricular systolic function was impaired in chronic alcoholic patients when compared with healthy controls.

Intraoperative Right Ventricular Fractional Area Change Is a Good Indicator of Right Ventricular Contractility: A Retrospective Comparison Using Two- and Three-Dimensional Echocardiography.

Science.gov (United States)

Imada, Tatsuyuki; Kamibayashi, Takahiko; Ota, Chiho; Carl Shibata, Sho; Iritakenishi, Takeshi; Sawa, Yoshiki; Fujino, Yuji

2015-08-01

Intraoperative two-dimensional echocardiography is technically challenging, given the unique geometry of the right ventricle (RV). It was hypothesized that the RV fractional area change (RVFAC) could be used as a simple method to evaluate RV function during surgery. Therefore, the correlation between the intraoperative RVFAC and the true right ventricular ejection fraction (RVEF), as measured using newly developed three-dimensional (3D) analysis software, was evaluated. Retrospective study. University hospital. Patients who underwent cardiac surgery with transesophageal echocardiography monitoring between March 2014 and June 2014. None. Sixty-two patients were included in this study. After the exclusion of poor imaging data and patients with arrhythmias, 54 data sets were analyzed. RVFAC was measured by one anesthesiologist during surgery, and full-volume 3D echocardiographic data were recorded simultaneously. The 3D data were analyzed postoperatively using off-line 3D analysis software by a second anesthesiologist, who was blinded to the RVFAC results. The mean RVFAC was 38.8% ± 8.7%, the mean RVEF was 41.4% ± 8.3%, and there was a good correlation between the RVFAC and the RVEF (r(2) = 0.638; prights reserved.

Massive supermultiplets in four-dimensional superstring theory

International Nuclear Information System (INIS)

Feng Wanzhe; Lüst, Dieter; Schlotterer, Oliver

2012-01-01

We extend the discussion of Feng et al. (2011) on massive Regge excitations on the first mass level of four-dimensional superstring theory. For the lightest massive modes of the open string sector, universal supermultiplets common to all four-dimensional compactifications with N=1,2 and N=4 spacetime supersymmetry are constructed respectively - both their vertex operators and their supersymmetry variations. Massive spinor helicity methods shed light on the interplay between individual polarization states.

Advanced echocardiography and clinical surrogates to risk stratify and manage patients with structural heart disease

NARCIS (Netherlands)

Debonnaire, Philippe Jean Marc Rita

2016-01-01

Part I focuses on the potential role of 3-dimensional echocardiography. At first a clinical risk score model for prediction of outcome in patients undergoing TAVI is presented (Chapter 2). Second the role of 3D-echocardiography is explored in depth in patients with mitral valve disease. Different

What Is Echocardiography?

Science.gov (United States)

... Intramural Research Home / Echocardiography Echocardiography Also known as Echo , Surface echo , Ultrasound of ... other tests, echo doesn't involve radiation. Transthoracic Echocardiography Transthoracic (tranz-thor-AS-ik) echo is the ...

The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty

NARCIS (Netherlands)

Wijdh-den Hamer, Inez J.; Bouma, Wobbe; Lai, Eric K.; Levack, Melissa M.; Shang, Eric K.; Pouch, Alison M.; Eperjesi, Thomas J.; Plappert, Theodore J.; Yushkevich, Paul A.; Hung, Judy; Mariani, Massimo A.; Khabbaz, Kamal R.; Gleason, Thomas G.; Mahmood, Feroze; Acker, Michael A.; Woo, Y. Joseph; Cheung, Albert T.; Gillespie, Matthew J.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.

Objectives: Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. Methods: Intraoperative

Sixty-four-slice multidetector computed tomography for preoperative evaluation of left ventricular function and mass in patients with mitral regurgitation: comparison with magnetic resonance imaging and echocardiography

International Nuclear Information System (INIS)

Guo, Ying-kun; Yang, Zhi-gang; Ning, Gang; Rao, Li; Pen, Ying; Wu, Yang; Dong, Li; Zhang, Tai-ming; Zhang, Xiao-chun; Wang, Qi-ling

2009-01-01

Quantitative values of left ventricular (LV) function and muscle mass in patients with mitral regurgitation are independent predictors of cardiac morbidity and mortality. The aim of this study was to prospectively evaluate whether 64-MDCT can assess the LV function in patients with mitral regurgitation with high accuracy when compared with the MRI and echocardiography results. Fifty-one patients with mitral regurgitation underwent retrospectively ECG-gated 64-MDCT, echocardiography, and MRI for assessing the global ventricular function. End-diastolic and end-systolic volume, stroke volume, ejection fraction, and mass were measured on 64-MDCT and echocardiography, and compared with the results measured on MRI which served as the reference standard. Intertechnique agreement was tested by using Pearson's correlation and Bland-Altman analyses. No significant differences were revealed in calculated LV function and mass between the 64-MDCT and MRI (paired t test, p = 0.07-0.53). Pearson's correlation analysis showed the functional parameters and mass correlated closely between the 64-MDCT and MRI (r = 0.89-0.96, p < 0.001). When compared with MRI, echocardiography underestimated the volumetric parameters of LV (paired t test, p = 0.0003-0.004), but significantly overestimated the EF values (p = 0.003), and moderate correlations of functional parameters were obtained (r = 0.78, 0.60, 0.81, and 0.62, respectively). ECG-gated 64-MDCT allows for accurate and reliable assessment of LV function in patients with mitral regurgitation, whereas LV volumes measured by two-dimensional echocardiography were underestimated and the ejection fraction was overestimated when compared with those achieved by using MRI. (orig.)

A systematic method for using 3D echocardiography to evaluate tricuspid valve insufficiency in hypoplastic left heart syndrome

OpenAIRE

Mart, Christopher Robin; Eckhauser, Aaron Wesley; Murri, Michael; Su, Jason Thomas

2014-01-01

With surgical palliation of hypoplastic left heart syndrome (HLHS), the tricuspid valve (TV) becomes the systemic atrioventricular valve and moderate/severe TV insufficiency (TVI), an adverse risk factor for survival to Fontan, has been reported in up to 35% of patients prior to stage I palliation. Precise echocardiographic identification of the mechanism of TVI cannot be determined by two-dimensional echocardiography. Three-dimensional echocardiography (3DE) can provide significant insight i...

Two-dimensional topological field theories coupled to four-dimensional BF theory

International Nuclear Information System (INIS)

Montesinos, Merced; Perez, Alejandro

2008-01-01

Four-dimensional BF theory admits a natural coupling to extended sources supported on two-dimensional surfaces or string world sheets. Solutions of the theory are in one to one correspondence with solutions of Einstein equations with distributional matter (cosmic strings). We study new (topological field) theories that can be constructed by adding extra degrees of freedom to the two-dimensional world sheet. We show how two-dimensional Yang-Mills degrees of freedom can be added on the world sheet, producing in this way, an interactive (topological) theory of Yang-Mills fields with BF fields in four dimensions. We also show how a world sheet tetrad can be naturally added. As in the previous case the set of solutions of these theories are contained in the set of solutions of Einstein's equations if one allows distributional matter supported on two-dimensional surfaces. These theories are argued to be exactly quantizable. In the context of quantum gravity, one important motivation to study these models is to explore the possibility of constructing a background-independent quantum field theory where local degrees of freedom at low energies arise from global topological (world sheet) degrees of freedom at the fundamental level

Fetal Echocardiography and Indications

Directory of Open Access Journals (Sweden)

Melih Atahan Güven

2008-09-01

Full Text Available Congenital heart diseases are encountered in 0.8% of live births and are among the most frequently diagnosed malformations. At least half of these anomalies end up with death or require surgical interventions and are responsible for 30% of the perinatal mortality. Fetal echocardiography is the sum of knowledge, skill and orientation rather than knowing the embryologic details of the fetal heart. The purpose of fetal echocardiography is to document the presence of normal fetal cardiac anatomy and rhythm in high risk group and to define the anomaly and arrhythmia if present. A certain sequence should be followed during the evaluation of fetal heart. Sequential segmental analysis (SSA and basic definition terminology made it possible to determine a lot of complex cardiac anomalies during prenatal period. By the end of 1970’s, Shinebourne started using sequential segmental analysis for fetal cardiac evaluation and today, prenatal diagnosis of congenital heart disease is possible without any confusion. In this manner, whole fetal heart can be evaluated as the relation of three segments (atria, ventricles and the great arteries with each other, irrelevant of complexity of a possible cardiac anomaly. Presence of increased nuchal thickness during early gestation and abnormal four-chamber-view during ultrasonography by the obstetrician presents a clear indication for fetal echocardiography,however, one should keep in mind that 80-90% of the babies born with a congenital heart disease do not have a familial or maternal risk factor. In addition, it should be remembered that expectant mothers with diabetes mellitus pose an indication for fetal echocardiography.

Fetal echocardiography

Science.gov (United States)

... page: //medlineplus.gov/ency/article/007340.htm Fetal echocardiography To use the sharing features on this page, please enable JavaScript. Fetal echocardiography is a test that uses sound waves ( ultrasound ) ...

Intraoperative Two- and Three-Dimensional Transesophageal Echocardiography in Combined Myectomy-Mitral Operations for Hypertrophic Cardiomyopathy.

Science.gov (United States)

Nampiaparampil, Robert G; Swistel, Daniel G; Schlame, Michael; Saric, Muhamed; Sherrid, Mark V

2018-03-01

Transesophageal echocardiography is essential in guiding the surgical approach for patients with obstructive hypertrophic cardiomyopathy. Septal hypertrophy, elongated mitral valve leaflets, and abnormalities of the subvalvular apparatus are prominent features, all of which may contribute to left ventricular outflow tract obstruction. Surgery aims to alleviate the obstruction via an extended myectomy, often with an intervention on the mitral valve and subvalvular apparatus. The goal of intraoperative echocardiography is to assess the anatomic pathology and pathophysiology in order to achieve a safe intraoperative course and a successful repair. This guide summarizes the systematic evaluation of these patients to determine the best surgical plan. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Three-dimensional transesophageal echocardiography: Principles and clinical applications

Directory of Open Access Journals (Sweden)

Annette Vegas

2016-01-01

Full Text Available A basic understanding of evolving 3D technology enables the echocardiographer to master the new skills necessary to acquire, manipulate, and interpret 3D datasets. Single button activation of specific 3D imaging modes for both TEE and transthoracic echocardiography (TTE matrix array probes include (a live, (b zoom, (c full volume (FV, and (d color Doppler FV. Evaluation of regional LV wall motion by RT 3D TEE is based on a change in LV chamber subvolume over time from altered segmental myocardial contractility. Unlike standard 2D TEE, there is no direct measurement of myocardial thickening or displacement of individual segments.

Measurement of left ventricular torsion using block-matching-based speckle tracking for two-dimensional echocardiography

Science.gov (United States)

Sun, Feng-Rong; Wang, Xiao-Jing; Wu, Qiang; Yao, Gui-Hua; Zhang, Yun

2013-01-01

Left ventricular (LV) torsion is a sensitive and global index of LV systolic and diastolic function, but how to noninvasively measure it is challenging. Two-dimensional echocardiography and the block-matching based speckle tracking method were used to measure LV torsion. Main advantages of the proposed method over the previous ones are summarized as follows: (1) The method is automatic, except for manually selecting some endocardium points on the end-diastolic frame in initialization step. (2) The diamond search strategy is applied, with a spatial smoothness constraint introduced into the sum of absolute differences matching criterion; and the reference frame during the search is determined adaptively. (3) The method is capable of removing abnormal measurement data automatically. The proposed method was validated against that using Doppler tissue imaging and some preliminary clinical experimental studies were presented to illustrate clinical values of the proposed method.

Echocardiography as an approach for canine cardiac disease diagnosis

Directory of Open Access Journals (Sweden)

P. Singh

2014-11-01

Full Text Available Aim: The aim of the study was to establish the methods for diagnosis various canine cardiac ailments using echocardiography. Materials and Methods: M-mode, two-dimensional echocardiography and Doppler studies were performed on 10 cases. Dogs showing signs of cardiac ailment either clinically, radiographic or via electrocardiographic examination were selected for study. Right parasternal short axis view was used for echocardiographic measurements. Right parasternal long axis and left parasternal apical views were used for Doppler studies. Doppler studies were performed at the level of aortic valve and atrioventricular valves for semi quantitative diagnosis of regurgitation. Results: Dogs were found affected with dilated cardiomyopathy (DCM (n=5, pericardial effusion (PE (n=1, combined PE and DCM (n=2 and remaining two showed abnormality on radiographic or electrographically evaluation but were found out to be normal echocardiographically (n=2. Conclusion: Echocardiography is an effective tool for diagnosis of various heart ailments.

The value of real-time three-dimensional transesophageal echocardiography in the assessment of paravalvular leak origin following prosthetic mitral valve replacement.

Science.gov (United States)

Yildiz, Mustafa; Duran, Nilüfer Ekşi; Gökdeniz, Tayyar; Kaya, Hasan; Ozkan, Mehmet

2009-09-01

Two-dimensional (2D) echocardiographic approaches are not sufficient to determine the origin of paravalvular leak (PVL) that occurs after prosthetic mitral valve replacement (MVR). In this study, we investigated the role of real-time three-dimensional transesophageal echocardiography (RT-3D TEE) in detecting the origin and size of PVL occurring after prosthetic MVR. The study included 13 patients (7 females; 6 males; mean age 56+/-10 years; range 37 to 71 years) who developed PVL within a mean of 8.3+/-3.8 years following mechanical prosthetic MVR. Nine patients (69.2%) had atrial fibrillation, and four patients (30.8%) had normal sinus rhythm. Four patients (30.8%) had hemolysis. Paravalvular leak was mild, moderate, and severe in two, six, and five patients, respectively. Real-time 3D TEE was performed using a 3D matrix-array TEE transducer immediately after detection of PVL on 2D TEE examination. Localization of PVL was made using a clock-wise format in relation to the aortic valve and the size of dehiscence was measured. The mean PVL width measured by 2D TEE was 3.00+/-0.92 mm. The mean length of dehiscence was 13.6+/-8.8 mm, and the mean width was 3.88+/-2.04 mm on RT-3D TEE. The PVLs were mainly localized in the posterior and anterior annular positions between 12 to 03 hours (n=7) and 06 to 09 hours (n=3) on RT-3D TEE, respectively, which corresponded to the posteromedial or anterolateral sectors of the posterior annulus. Considering that only the width of the PVL defect can be assessed by 2D TEE, delineation by RT-3D TEE includes the localization of PVL together with the length and width of the defect.

Commutative curvature operators over four-dimensional generalized symmetric

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Ali Haji-Badali

2014-12-01

Full Text Available Commutative properties of four-dimensional generalized symmetric pseudo-Riemannian manifolds were considered. Specially, in this paper, we studied Skew-Tsankov and Jacobi-Tsankov conditions in 4-dimensional pseudo-Riemannian generalized symmetric manifolds.

Three-dimensional echocardiographic assessment of atrial septal defects

Directory of Open Access Journals (Sweden)

Charles German

2015-01-01

Full Text Available Echocardiography provides a useful tool in the diagnosis of many congenital heart diseases, including atrial septal defects, and aids in further delineating treatment options. Although two-dimensional echocardiography has been the standard of care in this regard, technological advancements have made three-dimensional echocardiography possible, and the images obtained in this new imaging modality are able to accurately portray the morphology, location, dimensions, and dynamic changes of defects and many other heart structures during the cardiac cycle.

Usefulness of exercise echocardiography in ischemic heart disease. Comparison with exercise cardiac scintigraphy

International Nuclear Information System (INIS)

Tashiro, Hideki; Koyanagi, Samon; Narabayashi, Hideki; Inou, Tetsuji; Takeshita, Akira

1999-01-01

Exercise echocardiography and exercise thallium-201 ( 201 Tl) single photon emission computed tomography (SPECT) were performed in 152 patients with suspected coronary artery disease, including 61 patients with old myocardial infarction. All patients underwent coronary arteriography, and coronary artery disease was defined as ≥75% diameter stenosis. Digital two-dimensional echocardiography was performed before and after the treadmill exercise test, and wall motion abnormality was evaluated using quad-screen. Sensitivity and specificity for the diagnosis of coronary artery disease were similar for the 2 exercise tests (77% and 80% for echocardiography and 75%, and 83% for SPECT, respectively). Diagnoses for one-vessel disease, 2-vessel disease and 3-vessel disease were similar for echocardiography (79%, 72% and 77%, respectively) and SPECT (74%, 75% and 77%, respectively). Sensitivity for the diagnosis of ischemia at the area remote from infarct area was low for both exercise echocardiography and exercise SPECT (45% and 48%, respectively). Exercise echocardiography has comparable diagnostic value to SPECT for the detection of coronary artery disease. However, both exercise tests have limitations for the diagnosis of ischemia at the area remote from infarct area. (author)

Evaluation of changes in left ventricular structure and function in hypertensive patients with coronary artery disease after PCI using real-time three-dimensional echocardiography.

Science.gov (United States)

Meng, Yanhong; Zong, Ling; Zhang, Ziteng; Han, Youdong; Wang, Yanhui

2018-02-01

We aimed to evaluate the changes in left ventricular structure and function in hypertensive patients with coronary artery disease before and after percutaneous coronary intervention (PCI) using real-time three-dimensional echocardiography. Two hundred and eighty hypertensive patients with coronary artery disease undergoing PCI and 120 cases who did not receive PCI in our hospital were selected as the subjects of our study. All patients were administered with routine antiplatelet, anticoagulant, lipid-lowering, antihypertensive, dilating coronary artery and other medications. The left ventricular systolic function and systolic synchrony index changes before and after subjects were treated by PCI were analyzed using three-dimensional echocardiography. At 2 days before surgery, there were no significant differences in the left ventricular end-diastolic volume, left ventricular end-systolic volume (LVESV) and ejection fraction (EF) between the two patient groups (P>0.05). At 3 months and 9 months, the two key time points after PCI, the LVESV level in the PCI group was distinctly decreased, while EF was significantly increased (P0.05); however, the parameters of time from the corresponding segment of the myocardium to the minimal systolic volume in patients in the PCI group were significantly reduced at 3 and 9 months after surgery (PPCI accurately and in real-time, which may play a significant role.

[Real time 3D echocardiography

Science.gov (United States)

Bauer, F.; Shiota, T.; Thomas, J. D.

2001-01-01

Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

Unmanned Aerial System Four-Dimensional Gunnery Training Device Development

Science.gov (United States)

2017-10-01

Aerial System (UAS) Four-Dimensional Gunnery Training Device: Training Effectiveness Assessment (James & Miller, in press). 31 Technical ...Research Product 2018-05 Unmanned Aerial System Four-Dimensional Gunnery Training Device Development David R. James...for the Department of the Army by Northrop Grumman Corporation. Technical review by Thomas Rhett Graves, Ph.D., U.S. Army Research Institute

Transesophageal echocardiography. 3. rev. and enl. ed.; Transoesophageale Echokardiografie. Lehrbuch und Altlas zur Untersuchungstechnik und Befundinterpretation

Energy Technology Data Exchange (ETDEWEB)

Lambertz, Heinz [ECHOECUCT-Akademie, Wiesbaden (Germany); Lethen, Harald (eds.) [Internistische Intensivmedizin, Wiesbaden (Germany). Innere Medizin/Kardiologie

2013-02-01

The book on transesophageal echocardiography covers the following issues: Development of transesophageal echocardiography, technical advances; indications and contraindication for transesophageal echocardiography; systematic of the medical examination process; cardiac valves and valve prostheses; mitral and aortic valvuloplasty, TAVI and interventional treatment of mitral regurgitation; infectious endocarditis; one-way and effluence disturbances of the left and right ventricle; diseases of the thoracic aorta; undefined right ventricle enlargement; lung embolism, acute infarct complications; TEE during anesthesia and perioperative intensive medicine, cardiac sources of embolism; cardiac tumors, mediastinal lymph nodes; pericardiac diseases; congenital heart diseases in childhood and adulthood; catheter interventions and heart valve reconstruction; surgically corrected congenital cardiac defects; intracavitary versus transesophageal echocardiography; three-dimensional TEE; coronary diagnostics; ischemia and vitality diagnostics.

Evaluating four-loop conformal Feynman integrals by D-dimensional differential equations

Science.gov (United States)

Eden, Burkhard; Smirnov, Vladimir A.

2016-10-01

We evaluate a four-loop conformal integral, i.e. an integral over four four-dimensional coordinates, by turning to its dimensionally regularized version and applying differential equations for the set of the corresponding 213 master integrals. To solve these linear differential equations we follow the strategy suggested by Henn and switch to a uniformly transcendental basis of master integrals. We find a solution to these equations up to weight eight in terms of multiple polylogarithms. Further, we present an analytical result for the given four-loop conformal integral considered in four-dimensional space-time in terms of single-valued harmonic polylogarithms. As a by-product, we obtain analytical results for all the other 212 master integrals within dimensional regularization, i.e. considered in D dimensions.

Evaluating four-loop conformal Feynman integrals by D-dimensional differential equations

Energy Technology Data Exchange (ETDEWEB)

Eden, Burkhard [Institut für Mathematik und Physik, Humboldt-Universität zu Berlin,Zum großen Windkanal 6, 12489 Berlin (Germany); Smirnov, Vladimir A. [Skobeltsyn Institute of Nuclear Physics, Moscow State University,119992 Moscow (Russian Federation)

2016-10-21

We evaluate a four-loop conformal integral, i.e. an integral over four four-dimensional coordinates, by turning to its dimensionally regularized version and applying differential equations for the set of the corresponding 213 master integrals. To solve these linear differential equations we follow the strategy suggested by Henn and switch to a uniformly transcendental basis of master integrals. We find a solution to these equations up to weight eight in terms of multiple polylogarithms. Further, we present an analytical result for the given four-loop conformal integral considered in four-dimensional space-time in terms of single-valued harmonic polylogarithms. As a by-product, we obtain analytical results for all the other 212 master integrals within dimensional regularization, i.e. considered in D dimensions.

Lattice classification of the four-dimensional heterotic strings

International Nuclear Information System (INIS)

Balog, J.; Forgacs, P.; Vecsernyes, P.; Horvath, Z.

1987-06-01

A lattice slicing procedure is proposed which leads to the classification of all four-dimensional chiral heterotic strings based on Conway and Sloane's 22-dimensional self-dual Euclidean lattices. By reversing this procedure it is possible to construct all these theories. (author)

Renormalization of period doubling in symmetric four-dimensional volume-preserving maps

International Nuclear Information System (INIS)

Mao, J.; Greene, J.M.

1987-01-01

We have determined three maps (truncated at quadratic terms) that are fixed under the renormalization operator of pitchfork period doubling in symmetric four-dimensional volume-preserving maps. Each of these contains the previously known two-dimensional area-preserving map that is fixed under the period-doubling operator. One of these three fixed maps consists of two uncoupled two-dimensional (nonlinear) area-preserving fixed maps. The other two contain also the two-dimensional area-preserving fixed map coupled (in general) with a linear two-dimensional map. The renormalization calculation recovers all numerical results for the pitchfork period doubling in the symmetric four-dimensional volume-preserving maps, reported by Mao and Helleman [Phys. Rev. A 35, 1847 (1987)]. For a large class of nonsymmetric four-dimensional volume-preserving maps, we found that the fixed maps are the same as those for the symmetric maps

Evaluation of Left Ventricular Diastolic Dysfunction with Early Systolic Dysfunction Using Two-Dimensional Speckle Tracking Echocardiography in Canine Heart Failure Model.

Science.gov (United States)

Wu, Wei-Chun; Ma, Hong; Xie, Rong-Ai; Gao, Li-Jian; Tang, Yue; Wang, Hao

2016-04-01

This study evaluated the role of two-dimensional speckle tracking echocardiography (2DSTE) for predicting left ventricular (LV) diastolic dysfunction in pacing-induced canine heart failure. Pacing systems were implanted in 8 adult mongrel dogs, and continuous rapid right ventricular pacing (RVP, 240 beats/min) was maintained for 2 weeks. The obtained measurements from 2DSTE included global strain rate during early diastole (SRe) and during late diastole (SRa) in the longitudinal (L-SRe, L-SRa), circumferential (C-SRe, C-SRa), and radial directions (R-SRe, R-SRa). Changes in heart morphology were observed by light microscopy and transmission electron microscopy at 2 weeks. The onset of LV diastolic dysfunction with early systolic dysfunction occurred 3 days after RVP initiation. Most of the strain rate imaging indices were altered at 1 or 3 days after RVP onset and continued to worsen until heart failure developed. Light and transmission electron microscopy showed myocardial vacuolar degeneration and mitochondrial swelling in the left ventricular at 2 weeks after RVP onset. Pearson's correlation analysis revealed that parameters of conventional echocardiography and 2DSTE showed moderate correlation with LV pressure parameters, including E/Esep' (r = 0.58, P echocardiography and strain rate imaging could effectively predict LV diastolic dysfunction (area under the curve: E/Esep' 0.78; L-SRe 0.84; E/L-SRe 0.80; R-SRe 0.80). 2DSTE was a sensitive and accurate technique that could be used for predicting LV diastolic dysfunction in canine heart failure model. © 2015, Wiley Periodicals, Inc.

Four-dimensional Hall mechanics as a particle on CP3

International Nuclear Information System (INIS)

Bellucci, Stefano; Casteill, Pierre-Yves; Nersessian, Armen

2003-01-01

In order to establish an explicit connection between four-dimensional Hall effect on S 4 and six-dimensional Hall effect on CP 3 , we perform the Hamiltonian reduction of a particle moving on CP 3 in a constant magnetic field to the four-dimensional Hall mechanics (i.e., a-bar particle on S 4 in a SU(2) instanton field). This reduction corresponds to fixing the isospin of the latter system

Twistors and four-dimensional conformal field theory

International Nuclear Information System (INIS)

Singer, M.A.

1990-01-01

This is a report (with technical details omitted) on work concerned with generalizations to four dimensions of two-dimensional Conformed Field Theory. Accounts of this and related material are contained elsewhere. The Hilbert space of the four-dimensional theory has a natural interpretation in terms of massless spinor fields on real Minkowski space. From the twistor point of view this follows from the boundary CR-manifold P being precisely the space of light rays in real compactified Minkowski space. All the amplitudes can therefore be regarded as defined on Hilbert spaces built from Lorentzian spinor fields. Thus the twistor picture provides a kind of halfway house between the Lorentzian and Euclidean field theories. (author)

Echocardiography as an indication of continuous-time cardiac quiescence

Science.gov (United States)

Wick, C. A.; Auffermann, W. F.; Shah, A. J.; Inan, O. T.; Bhatti, P. T.; Tridandapani, S.

2016-07-01

Cardiac computed tomography (CT) angiography using prospective gating requires that data be acquired during intervals of minimal cardiac motion to obtain diagnostic images of the coronary vessels free of motion artifacts. This work is intended to assess B-mode echocardiography as a continuous-time indication of these quiescent periods to determine if echocardiography can be used as a cost-efficient, non-ionizing modality to develop new prospective gating techniques for cardiac CT. These new prospective gating approaches will not be based on echocardiography itself but on CT-compatible modalities derived from the mechanics of the heart (e.g. seismocardiography and impedance cardiography), unlike the current standard electrocardiogram. To this end, echocardiography and retrospectively-gated CT data were obtained from ten patients with varied cardiac conditions. CT reconstructions were made throughout the cardiac cycle. Motion of the interventricular septum (IVS) was calculated from both echocardiography and CT reconstructions using correlation-based, deviation techniques. The IVS was chosen because it (1) is visible in echocardiography images, whereas the coronary vessels generally are not, and (2) has been shown to be a suitable indicator of cardiac quiescence. Quiescent phases were calculated as the minima of IVS motion and CT volumes were reconstructed for these phases. The diagnostic quality of the CT reconstructions from phases calculated from echocardiography and CT data was graded on a four-point Likert scale by a board-certified radiologist fellowship-trained in cardiothoracic radiology. Using a Wilcoxon signed-rank test, no significant difference in the diagnostic quality of the coronary vessels was found between CT volumes reconstructed from echocardiography- and CT-selected phases. Additionally, there was a correlation of 0.956 between the echocardiography- and CT-selected phases. This initial work suggests that B-mode echocardiography can be used as a

Dynamic 3D echocardiography in virtual reality

Directory of Open Access Journals (Sweden)

Simoons Maarten L

2005-12-01

Full Text Available Abstract Background This pilot study was performed to evaluate whether virtual reality is applicable for three-dimensional echocardiography and if three-dimensional echocardiographic 'holograms' have the potential to become a clinically useful tool. Methods Three-dimensional echocardiographic data sets from 2 normal subjects and from 4 patients with a mitral valve pathological condition were included in the study. The three-dimensional data sets were acquired with the Philips Sonos 7500 echo-system and transferred to the BARCO (Barco N.V., Kortrijk, Belgium I-space. Ten independent observers assessed the 6 three-dimensional data sets with and without mitral valve pathology. After 10 minutes' instruction in the I-Space, all of the observers could use the virtual pointer that is necessary to create cut planes in the hologram. Results The 10 independent observers correctly assessed the normal and pathological mitral valve in the holograms (analysis time approximately 10 minutes. Conclusion this report shows that dynamic holographic imaging of three-dimensional echocardiographic data is feasible. However, the applicability and use-fullness of this technology in clinical practice is still limited.

Spinors and supersymmetry in four-dimensional Euclidean space

International Nuclear Information System (INIS)

McKeon, D.G.C.; Sherry, T.N.

2001-01-01

Spinors in four-dimensional Euclidean space are treated using the decomposition of the Euclidean space SO(4) symmetry group into SU(2)xSU(2). Both 2- and 4-spinor representations of this SO(4) symmetry group are shown to differ significantly from the corresponding spinor representations of the SO(3, 1) symmetry group in Minkowski space. The simplest self conjugate supersymmetry algebra allowed in four-dimensional Euclidean space is demonstrated to be an N=2 supersymmetry algebra which resembles the N=2 supersymmetry algebra in four-dimensional Minkowski space. The differences between the two supersymmetry algebras gives rise to different representations; in particular an analysis of the Clifford algebra structure shows that the momentum invariant is bounded above by the central charges in 4dE, while in 4dM the central charges bound the momentum invariant from below. Dimensional reduction of the N=1 SUSY algebra in six-dimensional Minkowski space (6dM) to 4dE reproduces our SUSY algebra in 4dE. This dimensional reduction can be used to introduce additional generators into the SUSY algebra in 4dE. Well known interpolating maps are used to relate the N=2 SUSY algebra in 4dE derived in this paper to the N=2 SUSY algebra in 4dM. The nature of the spinors in 4dE allows us to write an axially gauge invariant model which is shown to be both Hermitian and anomaly-free. No equivalent model exists in 4dM. Useful formulae in 4dE are collected together in two appendixes

The current status of fluoroscopy and echocardiography in the diagnosis of prosthetic valve thrombosis-a review article.

Science.gov (United States)

Gürsoy, Mustafa Ozan; Kalçik, Macit; Karakoyun, Süleyman; Özkan, Mehmet

2015-01-01

Prosthetic valve thrombosis (PVT) is a potentially life-threatening complication of heart valve replacement. Early diagnosis is crucial for the prevention of significantly morbid and lethal complications. Cinefluoroscopy (CF) and echocardiography have been widely used for diagnosing PVT. In recent years, the role of CF has declined since the introduction of transesophageal echocardiography and the great improvements in ultrasound technology including real time three-dimensional imaging. Nevertheless, both echocardiography and CF provide different kinds of information on prosthesis function, and therefore they are considered as complementary and not alternative. In this review, we aimed to summarize the current status of CF and echocardiography in the diagnosis of PVT. © 2014, Wiley Periodicals, Inc.

Design of a Matrix Transducer for Three-Dimensional Second Harmonic Transesophageal Echocardiography

Science.gov (United States)

Blaak, Sandra; van Neer, Paul L. M. J.; Prins, Christian; Bosch, Johan G.; Lancée, Charles T.; van der Steen, Antonius F. W.; de Jong, Nico

Three-dimensional (3D) echocardiography visualizes the 3D anatomy and function of the heart. For 3D imaging an ultrasound matrix of several thousands of elements is required. To connect the matrix to an external imaging system, smart signal processing with integrated circuitry in the tip of the TEE probe is required for channel reduction. To separate the low voltage integrated receive circuitry from the high voltages required for transmission, our design features a separate transmit and receive subarray. In this study we focus on the transmit subarray. A 3D model of an individual element was developed using the finite element method (FEM). The model was validated by laser interferometer and acoustic measurements. Measurement and simulations matched well. The maximum transmit transfer was 3 nm/V at 2.4 MHz for both the FEM simulation of an element in air and the laser interferometer measurement. The FEM simulation of an element in water resulted in a maximum transfer of 43 kPa/V at 2.3 MHz and the acoustic measurement in 55 kPa/V at 2.5 MHz. The maximum pressure is ~1 MPa/120Vpp, which is sufficient pressure for second harmonic imaging. The proposed design of the transmit subarray is suitable for its role in a 3D 2H TEE probe.

New digital measurement methods for left ventricular volume using real-time three-dimensional echocardiography: comparison with electromagnetic flow method and magnetic resonance imaging

Science.gov (United States)

Qin, J. J.; Jones, M.; Shiota, T.; Greenberg, N. L.; Firstenberg, M. S.; Tsujino, H.; Zetts, A. D.; Sun, J. P.; Cardon, L. A.; Odabashian, J. A.;

Intraventricular dyssynchrony in light chain amyloidosis: a new mechanism of systolic dysfunction assessed by 3-dimensional echocardiography

Directory of Open Access Journals (Sweden)

Truran Seth

2008-08-01

Full Text Available Abstract Background Light chain amyloidosis (AL is a rare but often fatal disease due to intractable heart failure. Amyloid deposition leads to diastolic dysfunction and often preserved ejection fraction. We hypothesize that AL is associated with regional systolic dyssynchrony. The aim is to compare left ventricular (LV regional synchrony in AL subjects versus healthy controls using 16-segment dyssynchrony index measured from 3-dimension-al (3D echocardiography. Methods Cardiac 3D echocardiography full volumes were acquired in 10 biopsy-proven AL subjects (60 ± 3 years, 5 females and 10 healthy controls (52 ± 1 years, 5 females. The LV was subdivided into 16 segments and the time from end-diastole to the minimal systolic volume for each of the 16 segments was expressed as a percent of the cycle length. The standard deviations of these times provided a 16-segment dyssynchrony index (16-SD%. 16-SD% was compared between healthy and AL subjects. Results Left ventricular ejection fraction was comparable (control vs. AL: 62.4 ± 0.6 vs. 58.6 ± 2.8%, p = NS. 16-SD% was significantly higher in AL versus healthy subjects (5.93 ± 4.4 vs. 1.67 ± 0.87%, p = 0.003. 16-SD% correlated with left ventricular mass index (R 0.45, p = 0.04 but not to left ventricular ejection fraction. Conclusion Light chain amyloidosis is associated with left ventricular regional systolic dyssynchrony. Regional dyssynchrony may be an unrecognized mechanism of heart failure in AL subjects.

Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy.

Science.gov (United States)

Khan, Sitara G; Klettas, Dimitris; Kapetanakis, Stam; Monaghan, Mark J

2016-03-01

Cardiac resynchronisation therapy (CRT) can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain) has conventionally been assessed using tissue Doppler imaging (TDI), which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference ('speckles') in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT. © 2016 The authors.

Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy

Directory of Open Access Journals (Sweden)

Sitara G Khan

2016-05-01

Full Text Available Cardiac resynchronisation therapy (CRT can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain has conventionally been assessed using tissue Doppler imaging (TDI, which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference (‘speckles’ in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT.

Four-dimensional optical manipulation of colloidal particles

DEFF Research Database (Denmark)

Rodrigo, P.J.; Daria, V.R.; Glückstad, J.

2005-01-01

We transform a TEM00 laser mode into multiple counterpropagating optical traps to achieve four-dimensional simultaneous manipulation of multiple particles. Efficient synthesis and dynamic control of the counterpropagating-beam traps is carried out via the generalized phase contrast method......, and a spatial polarization-encoding scheme. Our experiments genuinely demonstrate real-time, interactive particle-position control for forming arbitrary volumetric constellations and complex three-dimensional trajectories of multiple particles. This opens up doors for cross-disciplinary cutting-edge research...

Determinants of Pediatric Echocardiography Laboratory Productivity: Analysis from the Second Survey of the American Society of Echocardiography Committee on Echocardiography Laboratory Productivity.

Science.gov (United States)

Srivastava, Shubhika; Allada, Vivekanand; Younoszai, Adel; Lopez, Leo; Soriano, Brian D; Fleishman, Craig E; Van Hoever, Andrea M; Lai, Wyman W

2016-10-01

The American Society of Echocardiography Committee on Pediatric Echocardiography Laboratory Productivity aimed to study factors that could influence the clinical productivity of physicians and sonographers and assess longitudinal trends for the same. The first survey results indicated that productivity correlated with the total volume of echocardiograms. Survey questions were designed to assess productivity for (1) physician full-time equivalent (FTE) allocated to echocardiography reading (echocardiograms per physician FTE per day), (2) sonographer FTE (echocardiograms per sonographer FTE per year), and (3) machine utilization (echocardiograms per machine per year). Questions were also posed to assess work flow and workforce. For fiscal year 2013 or academic year 2012-2013, the mean number of total echocardiograms-including outreach, transthoracic, fetal, and transesophageal echocardiograms-per physician FTE per day was 14.3 ± 5.9, the mean number of echocardiograms per sonographer FTE per year was 1,056 ± 441, and the mean number of echocardiograms per machine per year was 778 ± 303. Both physician and sonographer productivity was higher at high-volume surgical centers and with echocardiography slots scheduled concordantly with clinic visits. Having an advanced imaging fellow and outpatient sedation correlated negatively with clinical laboratory productivity. Machine utilization was greater in laboratories with higher sonographer and physician productivity and lower for machines obtained before 2009. Measures of pediatric echocardiography laboratory staff productivity and machine utilization were shown to correlate positively with surgical volume, total echocardiography volumes, and concordant echocardiography scheduling; the same measures correlated negatively with having an advanced imaging fellow and outpatient sedation. There has been no significant change in staff productivity noted over two Committee on Pediatric Echocardiography Laboratory

Echocardiography Practice: Insights into Appropriate Clinical Use, Technical Competence and Quality Improvement Program

Science.gov (United States)

Kossaify, Antoine; Grollier, Gilles

2014-01-01

Echocardiography accounts for nearly half of all cardiac imaging techniques. It is a widely available and adaptable tool, as well as being a cost-effective and mainly a non-invasive test. In addition, echocardiography provides extensive clinical data, which is related to the presence or advent of different modalities (tissue Doppler imaging, speckle tracking imaging, three-dimensional mode, contrast echo, etc.), different approaches (transesophageal, intravascular, etc.), and different applications (ie, heart failure/resynchronization studies, ischemia/stress echo, etc.). In view of this, it is essential to conform to criteria of appropriate use and to keep standards of competence. In this study, we sought to review and discuss clinical practice of echocardiography in light of the criteria of appropriate clinical use, also we present an insight into echocardiographic technical competence and quality improvement project. PMID:24516342

Dynamic three-dimensional display of common congenital cardiac defects from reconstruction of two-dimensional echocardiographic images.

Science.gov (United States)

Hsieh, K S; Lin, C C; Liu, W S; Chen, F L

1996-01-01

Two-dimensional echocardiography had long been a standard diagnostic modality for congenital heart disease. Further attempts of three-dimensional reconstruction using two-dimensional echocardiographic images to visualize stereotypic structure of cardiac lesions have been successful only recently. So far only very few studies have been done to display three-dimensional anatomy of the heart through two-dimensional image acquisition because such complex procedures were involved. This study introduced a recently developed image acquisition and processing system for dynamic three-dimensional visualization of various congenital cardiac lesions. From December 1994 to April 1995, 35 cases were selected in the Echo Laboratory here from about 3000 Echo examinations completed. Each image was acquired on-line with specially designed high resolution image grazmber with EKG and respiratory gating technique. Off-line image processing using a window-architectured interactive software package includes construction of 2-D ehcocardiographic pixel to 3-D "voxel" with conversion of orthogonal to rotatory axial system, interpolation, extraction of region of interest, segmentation, shading and, finally, 3D rendering. Three-dimensional anatomy of various congenital cardiac defects was shown, including four cases with ventricular septal defects, two cases with atrial septal defects, and two cases with aortic stenosis. Dynamic reconstruction of a "beating heart" is recorded as vedio tape with video interface. The potential application of 3D display of the reconstruction from 2D echocardiographic images for the diagnosis of various congenital heart defects has been shown. The 3D display was able to improve the diagnostic ability of echocardiography, and clear-cut display of the various congenital cardiac defects and vavular stenosis could be demonstrated. Reinforcement of current techniques will expand future application of 3D display of conventional 2D images.

Four-dimensional conversion for spiritual leadership development: A ...

African Journals Online (AJOL)

The process of a four-dimensional conversion and/or transformation strives in helping the leadership of an organisation, especially such as the church, with practical ways that may lead to the development of an effective leadership by observing the four important aspects of human spirituality as elaborated on in the article.

Stress echocardiography expert consensus statement

NARCIS (Netherlands)

R. Sicari (Rosa); P. Nihoyannopoulos (Petros); A. Evangelista (Arturo); J. Kasprzak (Jaroslav); P. Lancellotti (Patrizio); D. Poldermans (Don); J.U. Voigt; J.L. Zamorano (Jose)

2008-01-01

textabstractStress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography

2010 Canadian Cardiovascular Society/Canadian Society of Echocardiography Guidelines for Training and Maintenance of Competency in Adult Echocardiography.

Science.gov (United States)

Burwash, Ian G; Basmadjian, Arsene; Bewick, David; Choy, Jonathan B; Cujec, Bibiana; Jassal, Davinder S; MacKenzie, Scott; Nair, Parvathy; Rudski, Lawrence G; Yu, Eric; Tam, James W

2011-01-01

Guidelines for the provision of echocardiography in Canada were jointly developed and published by the Canadian Cardiovascular Society and the Canadian Society of Echocardiography in 2005. Since their publication, recognition of the importance of echocardiography to patient care has increased, along with the use of focused, point-of-care echocardiography by physicians of diverse clinical backgrounds and variable training. New guidelines for physician training and maintenance of competence in adult echocardiography were required to ensure that physicians providing either focused, point-of-care echocardiography or comprehensive echocardiography are appropriately trained and proficient in their use of echocardiography. In addition, revision of the guidelines was required to address technological advances and the desire to standardize echocardiography training across the country to facilitate the national recognition of a physician's expertise in echocardiography. This paper summarizes the new Guidelines for Physician Training and Maintenance of Competency in Adult Echocardiography, which are considerably more comprehensive than earlier guidelines and address many important issues not previously covered. These guidelines provide a blueprint for physician training despite different clinical backgrounds and help standardize physician training and training programs across the country. Adherence to the guidelines will ensure that physicians providing echocardiography have acquired sufficient expertise required for their specific practice. The document will also provide a framework for other national societies to standardize their training programs in echocardiography and will provide a benchmark by which competency in adult echocardiography may be measured. Copyright © 2011 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Mid-term follow-up of patients with transposition of the great arteries after atrial inversion operation using two- and three-dimensional magnetic resonance imaging

International Nuclear Information System (INIS)

Fogel, Mark A.; Weinberg, Paul M.; Hubbard, Anne

2002-01-01

Background: Older patients with transposition of the great arteries who have undergone an atrial inversion procedure (ATRIAL-INV) are difficult to image by echocardiography. The surgical baffles are spatially complex. Objective: To test the hypothesis that two- and three-dimensional MRI can elucidate the spatially complex anatomy in this patient population. Materials and methods; Twelve patients with ATRIAL-INV, ages 16±4.5 years, underwent routine T1-weighted spin-echo axial imaging to obtain a full cardiac volumetric data set. Postprocessing created three-dimensional shaded surface displays and allowed for multiplanar reconstruction. Routine transthoracic echocardiography was available on all patients. Results: Three-dimensional reconstruction enabled complete spatial conceptualization of the venous pathways, and allowed for precise localization of a narrowed region in the upper limb of the systemic venous pathway found in two patients. This was subsequently confirmed on angiography. Routine MRI was able to image the full extent of the venous pathways in all 12 patients. Routine transthoracic echocardiography was able to visualize proximal portions of the venous pathways in eight (67%), the distal upper limb in five (42%), and the distal lower limb in four (33%) patients, and it was able to visualize the outflow tracts in all patients. Conclusion: Three-dimensional reconstruction adds important spatial information, which can be especially important in stenotic regions. Routine MRI is superior to transthoracic echocardiography in delineation of the systemic and pulmonary venous pathway anatomy of ATRIAL-INV patients at mid-term follow-up. Although transesophageal echocardiography is an option, it is more invasive. (orig.)

The practice of echocardiography

International Nuclear Information System (INIS)

Kraus, R.

1985-01-01

This volume is an anthology by noted authorities on all clinically useful aspects of echocardiography. Its articles cover such subjects as: historical perspectives, physics, instrumentation and techniques, M mode and 2D echocardiography

Comment on non-renormalization theorem in the four dimensional superstrings

International Nuclear Information System (INIS)

Soda, Jiro; Nakazawa, Naohito; Sakai, Kenji; Ojima, Shuichi.

1987-10-01

We discuss non-renormalization theorem in the context of the four dimensional superstrings. We explicitly demonstrate that the graviton 3-point one-loop amplitude does not vanish in contrast to the ten dimensional superstring theories. (author)

Hawking radiation from four-dimensional Schwarzschild black holes in M theory

International Nuclear Information System (INIS)

Das, S.R.; Mathur, S.D.; Ramadevi, P.

1999-01-01

Recently a method has been developed for relating four dimensional Schwarzschild black holes in M theory to near-extremal black holes in string theory with four charges, using suitably defined open-quotes boostsclose quotes and T dualities. We show that this method can be extended to obtain the emission rate of low energy massless scalars for the four dimensional Schwarzschild hole from the microscopic picture of radiation from the near extremal hole. copyright 1999 The American Physical Society

American Society of Echocardiography

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American Society of Echocardiography Join Ase Renew Member Portal Log In Membership Member Portal Log In Join ASE Renew Benefits Rates FASE – Fellow of the American Society of Echocardiography Member Referral Program FAQs Initiatives Advocacy Awards, Grants, ...

Feasibility of four-dimensional preoperative simulation for elbow debridement arthroplasty.

Science.gov (United States)

Yamamoto, Michiro; Murakami, Yukimi; Iwatsuki, Katsuyuki; Kurimoto, Shigeru; Hirata, Hitoshi

2016-04-02

Recent advances in imaging modalities have enabled three-dimensional preoperative simulation. A four-dimensional preoperative simulation system would be useful for debridement arthroplasty of primary degenerative elbow osteoarthritis because it would be able to detect the impingement lesions. We developed a four-dimensional simulation system by adding the anatomical axis to the three-dimensional computed tomography scan data of the affected arm in one position. Eleven patients with primary degenerative elbow osteoarthritis were included. A "two rings" method was used to calculate the flexion-extension axis of the elbow by converting the surface of the trochlea and capitellum into two rings. A four-dimensional simulation movie was created and showed the optimal range of motion and the impingement area requiring excision. To evaluate the reliability of the flexion-extension axis, interobserver and intraobserver reliabilities regarding the assessment of bony overlap volumes were calculated twice for each patient by two authors. Patients were treated by open or arthroscopic debridement arthroplasties. Pre- and postoperative examinations included elbow range of motion measurement, and completion of the patient-rated questionnaire Hand20, Japanese Orthopaedic Association-Japan Elbow Society Elbow Function Score, and the Mayo Elbow Performance Score. Measurement of the bony overlap volume showed an intraobserver intraclass correlation coefficient of 0.93 and 0.90, and an interobserver intraclass correlation coefficient of 0.94. The mean elbow flexion-extension arc significantly improved from 101° to 125°. The mean Hand20 score significantly improved from 52 to 22. The mean Japanese Orthopaedic Association-Japan Elbow Society Elbow Function Score significantly improved from 67 to 88. The mean Mayo Elbow Performance Score significantly improved from 71 to 91 at the final follow-up evaluation. We showed that four-dimensional, preoperative simulation can be generated by

Evaluation of Left Atrial Volumes Using Multidetector Computed Tomography: Comparison with Echocardiography

International Nuclear Information System (INIS)

Gweon, Hye Mi; Kim, Sang Jin; Kim, Tae Hoon; Lee, Sang Min; Hong, Yoo Jin; Rim, Se Joong

2010-01-01

To prospectively assess the relationship between the two different measurement methods for the evaluation of left atrial (LA) volume using cardiac multidetector computed tomography (MDCT) and to compare the results between cardiac MDCT and echocardiography. Thirty-five patients (20 men, 15 women; mean age, 60 years) underwent cardiac MDCT angiography for coronary artery disease. The LA volumes were measured using two different methods: the two dimensional (2D) length-based (LB) method measured along the three-orthogonal planes of the LA and the 3D volumetric threshold-based (VTB) method measured according to the threshold 3D segmentation of the LA. The results obtained by cardiac MDCT were compared with those obtained by echocardiography. The LA end-systolic and end-diastolic volumes (LAESV and LAEDV) measured by the 2D-LB method correlated well with those measured by the 3DVTB method using cardiac MDCT (r = 0.763, r = 0.786, p = 0.001). However, there was a significant difference in the LAESVs between the two measurement methods using cardiac MDCT (p < 0.05). The LAESV measured by cardiac MDCT correlated well with measurements by echocardiography (r = 0.864, p = 0.001), however with a significant difference (p < 0.01) in their volumes. The cardiac MDCT overestimated the LAESV by 22% compared to measurements by echocardiography. A significant correlation was found between the two different measurement methods for evaluating LA volumes by cardiac MDCT. Further, cardiac MDCT correlates well with echocardiography in evaluating the LA volume. However, there are significant differences in the LAESV between the two measurement methods using cardiac MDCT and between cardiac MDCT and echocardiography

Four-dimensional computed tomography angiographic evaluation of cranial dural arteriovenous fistula before and after embolization.

Science.gov (United States)

Tian, Bing; Xu, Bing; Lu, Jianping; Liu, Qi; Wang, Li; Wang, Minjie

2015-06-01

This study aimed to evaluate the usefulness of four-dimensional CTA before and after embolization treatment with ONYX-18 in eleven patients with cranial dural arteriovenous fistulas, and to compare the results with those of the reference standard DSA. Eleven patients with cranial dural arteriovenous fistulas detected on DSA underwent transarterial embolization with ONYX-18. Four-dimensional CTA was performed an average of 2 days before and 4 days after DSA. Four-dimensional CTA and DSA images were reviewed by two neuroradiologists for identification of feeding arteries and drainage veins and for determining treatment effects. Interobserver and intermodality agreement between four-dimensional CTA and DSA were assessed. Forty-two feeding arteries were identified for 14 fistulas in the 11 patients. Of these, 36 (85.71%) were detected on four-dimensional CTA. After transarterial embolization, one patient got partly embolized, and the fistulas in the remaining 10 patients were completely occluded. The interobserver agreement for four-dimensional CTA and intermodality agreement between four-dimensional CTA and DSA were excellent (κ=1) for shunt location, identification of drainage veins, and fistula occlusion after treatment. Four-dimensional CTA images are highly accurate when compared with DSA images both before and after transarterial embolization treatment. Four-dimensional CTA can be used for diagnosis as well as follow-up of cranial dural arteriovenous fistulas in clinical settings. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparative study between MRI and echocardiography in noncompaction of ventricular myocardium

International Nuclear Information System (INIS)

Sun Ziyan; Xia Liming; Wang Chengyuan; Rao Jingjing; Shenyu Weihui

2007-01-01

Objective: To investigate the MRI and echocardiography manifestations of noncompaction of ventricular myocardium(NVM) and assess the role of MR1 in the diagnosis of NVM by comparing it with echocardiography. Methods: Fourteen cases of NVM diagnosed by echocardiography were examined with MRI, including scanning of black-blood sequences, double inversion recovery fast spin echo (DIBFSE) and triple inversion recovery fast spin echo (TIRFSE), and white blood sequence: fast imaging employ steady state acquisition (FIESTA). Scanning plane includes short axis view, four-chamber view and long axis view. Results: Both MRI and echocardiography displayed involvement of left ventricles in thirteen cases and involvement of double ventricles in one case. Apexes of heart and the intermedius are commonly affected. MRI showed 54 segments and echocardiography showed 53 segments affected, and there is no significant difference between the capability of MRI and echocardiography (P=1,000). The affected myocardium consisted of two layers: subendocardial noncompacted myocardium and epicardial compacted myocardium, and the ratio measurement of N/C by MRI was 3.37±0.89 and it was 3.19±0.82 by echocardiography. Noncompacted myocardium was characterized by prominent and excessive myocardial trabeculations and deep intratrabecular recesses, in which the blood flow was communicated with the ventricle. One case was complicated with ventricular aneurysm, and coronary arteriography was performed with unremarkable findings. One case underwent heart transplantation because of progressive heart failure, Gross findings demonstrated prominent muscular' trabeculations with deep intratrabecular recesses, which coincided well with MRI findings. Conclusion: The MRI manifestation of NVM is characteristic, and MRI with multiple series and planes is helpful in the diagnose of NVM. Compared with echocardiography, MRI could display the pathological cardiac muscle more clearly, because of its high soft

Higher-order gravity in higher dimensions: geometrical origins of four-dimensional cosmology?

Energy Technology Data Exchange (ETDEWEB)

Troisi, Antonio [Universita degli Studi di Salerno, Dipartimento di Fisica ' ' E.R. Caianiello' ' , Salerno (Italy)

2017-03-15

Determining the cosmological field equations is still very much debated and led to a wide discussion around different theoretical proposals. A suitable conceptual scheme could be represented by gravity models that naturally generalize Einstein theory like higher-order gravity theories and higher-dimensional ones. Both of these two different approaches allow one to define, at the effective level, Einstein field equations equipped with source-like energy-momentum tensors of geometrical origin. In this paper, the possibility is discussed to develop a five-dimensional fourth-order gravity model whose lower-dimensional reduction could provide an interpretation of cosmological four-dimensional matter-energy components. We describe the basic concepts of the model, the complete field equations formalism and the 5-D to 4-D reduction procedure. Five-dimensional f(R) field equations turn out to be equivalent, on the four-dimensional hypersurfaces orthogonal to the extra coordinate, to an Einstein-like cosmological model with three matter-energy tensors related with higher derivative and higher-dimensional counter-terms. By considering the gravity model with f(R) = f{sub 0}R{sup n} the possibility is investigated to obtain five-dimensional power law solutions. The effective four-dimensional picture and the behaviour of the geometrically induced sources are finally outlined in correspondence to simple cases of such higher-dimensional solutions. (orig.)

Oscillator potential for the four-dimensional Hall effect

International Nuclear Information System (INIS)

Mardoyan, Levon; Nersessian, Armen

2005-01-01

We suggest an exactly solvable model of an oscillator on a four-dimensional sphere interacting with an SU(2) Yang monopole. We show that the properties of the model essentially depend on the monopole charge

Identification of Architectural Functions in A Four-Dimensional Space

Directory of Open Access Journals (Sweden)

Firza Utama

2012-06-01

Full Text Available This research has explored the possibilities and concept of architectural space in a virtual environment. The virtual environment exists as a different concept, and challenges the constraints of the physical world. One of the possibilities in a virtual environment is that it is able to extend the spatial dimension higher than the physical three-dimension. To take the advantage of this possibility, this research has applied some geometrical four-dimensional (4D methods to define virtual architectural space. The spatial characteristics of 4D space is established by analyzing the four-dimensional structure that can be comprehended by human participant for its spatial quality, and by developing a system to control the fourth axis of movement. Multiple three-dimensional spaces that fluidly change their volume have been defined as one of the possibilities of virtual architecturalspace concept in order to enrich our understanding of virtual spatial experience.

Echocardiography-guided or "sided" pericardiocentesis.

Science.gov (United States)

Degirmencioglu, Aleks; Karakus, Gultekin; Güvenc, Tolga Sinan; Pinhan, Osman; Sipahi, Ilke; Akyol, Ahmet

2013-10-01

Echocardiography-guided pericardiocentesis is the first choice method for relieving cardiac tamponade, but the exact role of the echocardiography at the moment of the puncture is still controversial. In this report, detailed echocardiographic evaluation was performed in 21 consecutive patients with cardiac tamponade just before the pericardiocentesis. Appropriate needle position was determined according to the probe position using imaginary x, y, and z axes. Pericardiocentesis was performed successfully using this technique without simultaneous echocardiography and no complications were observed. We concluded that bedside echocardiography with detailed evaluation of the puncture site and angle is enough for pericardiocentesis instead of real time guiding. © 2013, Wiley Periodicals, Inc.

Four-dimensional Printing of Liquid Crystal Elastomers.

Science.gov (United States)

Ambulo, Cedric P; Burroughs, Julia J; Boothby, Jennifer M; Kim, Hyun; Shankar, M Ravi; Ware, Taylor H

2017-10-25

Three-dimensional structures capable of reversible changes in shape, i.e., four-dimensional-printed structures, may enable new generations of soft robotics, implantable medical devices, and consumer products. Here, thermally responsive liquid crystal elastomers (LCEs) are direct-write printed into 3D structures with a controlled molecular order. Molecular order is locally programmed by controlling the print path used to build the 3D object, and this order controls the stimulus response. Each aligned LCE filament undergoes 40% reversible contraction along the print direction on heating. By printing objects with controlled geometry and stimulus response, magnified shape transformations, for example, volumetric contractions or rapid, repetitive snap-through transitions, are realized.

Clinical study on left atrial thrombi. Comparative study between echocardiography and CT scan

Energy Technology Data Exchange (ETDEWEB)

Shimada, E; Asano, H; Kurasawa, T; Mitsumoto, K; Yamane, Y [Tokyo Kosei-Nenkin Hospital (Japan)

1981-09-01

We studied left atrial thrombi (LAT) by both echocardiography and computed tomography (CT) and compared the features of the 2 methods. A total of 15 patients with mitral stenosis complicated by atrial fibrillation were selected as the subjects. LAT were noted on the M-mode echocardiograms in 2 patients including a questionably positive one, on the two-dimensional echocardiograms in 5, and on the CT scans in 6 of 15. The history of thromboembolism was rather frequent and was found in 7 of 15 patients. However, LAT was found in only 3 of these on the CT scans. A shaggy or fuzzy pattern on the M-mode echocardiogram cannot be regarded as representing thrombi, while a laminar pattern undoubtedly represented thrombi. Two-dimensional echocardiography has considerably contributed to the improved detection rate of LAT. For the characteristic properties of ultrasound beams, however, it was impossible to investigate the entire left atrium. The detection of the thrombi in the appendage was especially difficult. However, computed tomography, permitting transverse cross-sectional tomography, was capable of sectioning the heart even in the presence of air and bones. The measurement of CT values was suggestive of the properties of the substance or substances involved, and also allowed the presumption as to whether the thrombus has been fibrosed. Furthermore, it was possible to estimate more accurately as well as 3-dimensionally the location, shape and dimensions of the thrombi by the reconstruction of the heart according to the CT values. It was concluded that echocardiography and computed tomography are the mutual aid to further improvement in the detection rate of left atrial thrombi.

Four-dimensional optical coherence tomography imaging of total liquid ventilated rats

Science.gov (United States)

Kirsten, Lars; Schnabel, Christian; Gaertner, Maria; Koch, Edmund

2013-06-01

Optical coherence tomography (OCT) can be utilized for the spatially and temporally resolved visualization of alveolar tissue and its dynamics in rodent models, which allows the investigation of lung dynamics on the microscopic scale of single alveoli. The findings could provide experimental input data for numerical simulations of lung tissue mechanics and could support the development of protective ventilation strategies. Real four-dimensional OCT imaging permits the acquisition of several OCT stacks within one single ventilation cycle. Thus, the entire four-dimensional information is directly obtained. Compared to conventional virtual four-dimensional OCT imaging, where the image acquisition is extended over many ventilation cycles and is triggered on pressure levels, real four-dimensional OCT is less vulnerable against motion artifacts and non-reproducible movement of the lung tissue over subsequent ventilation cycles, which widely reduces image artifacts. However, OCT imaging of alveolar tissue is affected by refraction and total internal reflection at air-tissue interfaces. Thus, only the first alveolar layer beneath the pleura is visible. To circumvent this effect, total liquid ventilation can be carried out to match the refractive indices of lung tissue and the breathing medium, which improves the visibility of the alveolar structure, the image quality and the penetration depth and provides the real structure of the alveolar tissue. In this study, a combination of four-dimensional OCT imaging with total liquid ventilation allowed the visualization of the alveolar structure in rat lung tissue benefiting from the improved depth range beneath the pleura and from the high spatial and temporal resolution.

Speckle tracking echocardiography in mature Irish Wolfhound dogs

DEFF Research Database (Denmark)

Westrup, Ulrik; McEvoy, Fintan

2013-01-01

Two-dimensional strain measurements obtained by speckle tracking echocardiography (STE) have been reported in both humans and dogs. Incorporation of this technique into canine clinical practice requires the availability of measurements from clinically normal dogs, ideally of the same breed, taken...... under normal clinical conditions.The aims of this prospective study were to assess if it is possible to obtain STE data during a routine echocardiographic examination in Irish Wolfhound dogs and that these data will provide reference values and an estimation of measurement error....

Common time in a four-dimensional symmetry framework

International Nuclear Information System (INIS)

Hsu, J.P.; Sherry, T.N.

1980-01-01

Following the ideas of Poincare, Reichenbach, and Grunbaum concerning the convention of setting up clock systems, we analyze clock systems and light propagation within the framework of four-dimensional symmetry. It is possible to construct a new four-dimensional symmetry framework incorporating common time: observers in different inertial frames of reference use one and the same clock system, which is located in any one of the frames. Consequently, simultaneity has a meaning independent of position and independent of frame of reference. A further consequence is that the two-way speeds of light alone are isotropic in any frame. By the choice of clock system there will be one frame in which the one-way speed of light is isotropic. This frame can be arbitrarily chosen. The difference between one-way speeds an two-way speeds of light signals is considered in detail

Clinical applications of contrast echocardiography

International Nuclear Information System (INIS)

Jorge, Leon Galindo

2005-01-01

The echocardiography is the technique more used for the diagnosis and pursuit of the cardiovascular illnesses; therefore, their diagnostic precision has acquired a vital importance in the handling of the patients with cardiovascular pathologies. However, with relative frequency, the diagnostic capacity of the echocardiography exam is diminished by limitations of the acoustic window, mainly in-patient with obesity, lung illnesses and alterations of the thoracic wall. This can be obviated with the use of the intra-esophagus echocardiography, although this it is a procedure semi-invasive and not very practical of carrying out in all the patients with problems of acoustic window. In this article the clinical applications are revised more common of the contrast echocardiography

Statistical Entropy of Four-Dimensional Extremal Black Holes

International Nuclear Information System (INIS)

Maldacena, J.M.; Strominger, A.

1996-01-01

String theory is used to count microstates of four-dimensional extremal black holes in compactifications with N=4 and N=8 supersymmetry. The result agrees for large charges with the Bekenstein-Hawking entropy. copyright 1996 The American Physical Society

Three-dimensional echocardiography: assessment of inter- and intra-operator variability and accuracy in the measurement of left ventricular cavity volume and myocardial mass

International Nuclear Information System (INIS)

Nadkarni, S.K.; Drangova, M.; Boughner, D.R.; Fenster, A.; Department of Medical Biophysics, Medical Sciences Building, University of Western Ontario, London, Ontario N6A 5C1

2000-01-01

Accurate left ventricular (LV) volume and mass estimation is a strong predictor of cardiovascular morbidity and mortality. We propose that our technique of 3D echocardiography provides an accurate quantification of LV volume and mass by the reconstruction of 2D images into 3D volumes, thus avoiding the need for geometric assumptions. We compared the accuracy and variability in LV volume and mass measurement using 3D echocardiography with 2D echocardiography, using in vitro studies. Six operators measured the LV volume and mass of seven porcine hearts, using both 3D and 2D techniques. Regression analysis was used to test the accuracy of results and an ANOVA test was used to compute variability in measurement. LV volume measurement accuracy was 9.8% (3D) and 18.4% (2D); LV mass measurement accuracy was 5% (3D) and 9.2% (2D). Variability in LV volume quantification with 3D echocardiography was %SEM inter = 13.5%, %SEM intra = 11.4%, and for 2D echocardiography was %SEM inter = 21.5%, %SEM intra = 19.1%. We derived an equation to predict uncertainty in measurement of LV volume and mass using 3D echocardiography, the results of which agreed with our experimental results to within 13%. 3D echocardiography provided twice the accuracy for LV volume and mass measurement and half the variability for LV volume measurement as compared with 2D echocardiography. (author)

Variability of four-dimensional computed tomography patient models

NARCIS (Netherlands)

Sonke, Jan-Jakob; Lebesque, Joos; van Herk, Marcel

2008-01-01

PURPOSE: To quantify the interfractional variability in lung tumor trajectory and mean position during the course of radiation therapy. METHODS AND MATERIALS: Repeat four-dimensional (4D) cone-beam computed tomography (CBCT) scans (median, nine scans/patient) routinely acquired during the course of

Shifts of integration variable within four- and N-dimensional Feynman integrals

International Nuclear Information System (INIS)

Elias, V.; McKeon, G.; Mann, R.B.

1983-01-01

We resolve inconsistencies between integration in four dimensions, where shifts of integration variable may lead to surface terms, and dimensional regularization, where no surface terms accompany such shifts, by showing that surface terms arise only for discrete values of the dimension parameter. General formulas for variable-of-integration shifts within N-dimensional Feynman integrals are presented, and the VVA triangle anomaly is interpreted as a manifestation of surface terms occurring in exactly four dimensions

Advanced quantitative echocardiography in arrhythmogenic right ventricular cardiomyopathy

DEFF Research Database (Denmark)

Kjaergaard, Jesper; Hastrup Svendsen, Jesper; Sogaard, Peter

2007-01-01

BACKGROUND: Arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) is a regional disease of the RV myocardium with variable degrees of left ventricular involvement. Three-dimensional echocardiography and Doppler tissue imaging (DTI) are new echocardiographic modalities for the evaluation......, patients with ARVC had a decreased RV ejection fraction (0.47 +/- 0.08 vs 0.53 +/- 0.05, P vs 15.1 +/- 3.7 cm/s, P left ventricle (7.0 +/- 2.6 vs 9.5 +/- 1.9 cm/s, P ... of the longitudinal motility appears to be a sensitive marker of preclinical left ventricular involvement....

Measurement of cardiac dimensions with two-dimensional echocardiography in the living horse.

Science.gov (United States)

Voros, K; Holmes, J R; Gibbs, C

1991-11-01

Two-dimensional echocardiography (2DE) was performed on 22 unsedated Thoroughbred and part Thoroughbred horses weighing between 411 and 650 kg to establish normal reference values for 2DE measurements. Animals stood during examinations performed with a 3.5 MHz mechanical sector transducer using various transducer positions and tomographic planes. Right ventricular diameter (RVD), ventricular septal thickness (VSTh), aortic diameter (AoD), area of the chordal lumen of the left ventricle (CTA), left ventricular diameter (LVD) and left atrial diameter (LAD) were determined at ventricular end-diastole (Ed) and/or end-systole (Es). Fractional shortening (FS) of the left ventricle and end-systolic left atrial to aortic ratio (LAD-Es:AoD-Es) also were calculated. Echocardiographic data were related to body weight by linear regression analysis. Intra-observer variability was checked in five horses by measuring each parameter during each of 10 consecutive cardiac cycles. The 2DE data were compared with M-mode values in published reports. In the 18 horses whose weight did not exceed 551 kg, repeatable recordings of good quality were obtained, and 2DE measurements could be made using intra-cardiac reference points. Increasing body weight proved to impose substantial limitations on measurements taken with the available machine and transducer. This problem might be overcome by using probes of lower frequency or equipment with higher quality image display at greater depth. The following parameters correlated significantly to body weight: VSTh-Es (r = 0.69; P less than 0.01). AoD-Es (r = 0.64; P less than 0.01) and CTA-Es (r = 0.84; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf

Directory of Open Access Journals (Sweden)

Matheus M. Mantovani

2012-12-01

Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.

Incremental benefit of 3D transesophageal echocardiography: a case of a mass overlying a prosthetic mitral valve.

Science.gov (United States)

Tauras, James M; Zhang, Zhihang; Taub, Cynthia C

2011-05-01

A young woman with a mechanical mitral valve and prosthetic mitral stenosis underwent multiple imaging modalities (including transthoracic ECHO, fluoroscopy, and two-dimensional transesophageal ECHO) to determine the cause of her stenosis. Only three-dimensional transesophageal echocardiography demonstrated the full size and extent of an obstructing mass on the strut and sewing ring of the prosthetic mitral valve. © 2011, Wiley Periodicals, Inc.

Guideline from Japanese Society of Echocardiography: 2018 focused update incorporated into Guidance for the Management and Maintenance of Echocardiography Equipment.

Science.gov (United States)

Daimon, Masao; Akaishi, Makoto; Asanuma, Toshihiko; Hashimoto, Shuji; Izumi, Chisato; Iwanaga, Shiro; Kawai, Hiroya; Toide, Hiroyuki; Hayashida, Akihiro; Yamada, Hirotsugu; Murata, Mitsushige; Hirano, Yutaka; Suzuki, Kengo; Nakatani, Satoshi

2018-03-01

Echocardiography plays a pivotal role as an imaging modality in the modern cardiology practice. Information derived from echocardiography is definitely helpful for a patient care. The Japanese Society of Echocardiography has promoted echocardiography for a routine clinical and research use. One of the missions of the Society is to provide information that is useful for high-quality examinations. To ensure it, we believe equipment in good conditions and a comfortable environment are important for both a patient and an examiner. Thus, the Committee for Guideline Writing, the Japanese Society of Echocardiography published brief guidance for the routine use of echocardiography equipment in 2015. Recently, the importance of international standardization has been emphasized in the medical laboratories. Accordingly, the committee has revised and updated our guidance for the routine use of echocardiography equipment.

Four-dimensional computed tomography angiographic evaluation of cranial dural arteriovenous fistula before and after embolization

International Nuclear Information System (INIS)

Tian, Bing; Xu, Bing; Lu, Jianping; Liu, Qi; Wang, Li; Wang, Minjie

2015-01-01

Highlights: • 4D CTA showed excellent agreement with DSA with regard to identification of feeding arteries and drainage veins. • The most important finding was 4D CTA in determining the impact of DAVF treatment with transarterial embolization. • 4D CTA provides images similar to those obtained with DSA both before and after treatment. - Abstract: Purpose: This study aimed to evaluate the usefulness of four-dimensional CTA before and after embolization treatment with ONYX-18 in eleven patients with cranial dural arteriovenous fistulas, and to compare the results with those of the reference standard DSA. Patients and Methods: Eleven patients with cranial dural arteriovenous fistulas detected on DSA underwent transarterial embolization with ONYX-18. Four-dimensional CTA was performed an average of 2 days before and 4 days after DSA. Four-dimensional CTA and DSA images were reviewed by two neuroradiologists for identification of feeding arteries and drainage veins and for determining treatment effects. Interobserver and intermodality agreement between four-dimensional CTA and DSA were assessed. Results: Forty-two feeding arteries were identified for 14 fistulas in the 11 patients. Of these, 36 (85.71%) were detected on four-dimensional CTA. After transarterial embolization, one patient got partly embolized, and the fistulas in the remaining 10 patients were completely occluded. The interobserver agreement for four-dimensional CTA and intermodality agreement between four-dimensional CTA and DSA were excellent (κ = 1) for shunt location, identification of drainage veins, and fistula occlusion after treatment. Conclusion: Four-dimensional CTA images are highly accurate when compared with DSA images both before and after transarterial embolization treatment. Four-dimensional CTA can be used for diagnosis as well as follow-up of cranial dural arteriovenous fistulas in clinical settings

Four-dimensional maps of the human somatosensory system.

Science.gov (United States)

Avanzini, Pietro; Abdollahi, Rouhollah O; Sartori, Ivana; Caruana, Fausto; Pelliccia, Veronica; Casaceli, Giuseppe; Mai, Roberto; Lo Russo, Giorgio; Rizzolatti, Giacomo; Orban, Guy A

2016-03-29

A fine-grained description of the spatiotemporal dynamics of human brain activity is a major goal of neuroscientific research. Limitations in spatial and temporal resolution of available noninvasive recording and imaging techniques have hindered so far the acquisition of precise, comprehensive four-dimensional maps of human neural activity. The present study combines anatomical and functional data from intracerebral recordings of nearly 100 patients, to generate highly resolved four-dimensional maps of human cortical processing of nonpainful somatosensory stimuli. These maps indicate that the human somatosensory system devoted to the hand encompasses a widespread network covering more than 10% of the cortical surface of both hemispheres. This network includes phasic components, centered on primary somatosensory cortex and neighboring motor, premotor, and inferior parietal regions, and tonic components, centered on opercular and insular areas, and involving human parietal rostroventral area and ventral medial-superior-temporal area. The technique described opens new avenues for investigating the neural basis of all levels of cortical processing in humans.

Four Dimensional Trace Space Measurement

Energy Technology Data Exchange (ETDEWEB)

Hernandez, M.

2005-02-10

Future high energy colliders and FELs (Free Electron Lasers) such as the proposed LCLS (Linac Coherent Light Source) at SLAC require high brightness electron beams. In general a high brightness electron beam will contain a large number of electrons that occupy a short longitudinal duration, can be focused to a small transverse area while having small transverse divergences. Therefore the beam must have a high peak current and occupy small areas in transverse phase space and so have small transverse emittances. Additionally the beam should propagate at high energy and have a low energy spread to reduce chromatic effects. The requirements of the LCLS for example are pulses which contain 10{sup 10} electrons in a temporal duration of 10 ps FWHM with projected normalized transverse emittances of 1{pi} mm mrad[1]. Currently the most promising method of producing such a beam is the RF photoinjector. The GTF (Gun Test Facility) at SLAC was constructed to produce and characterize laser and electron beams which fulfill the LCLS requirements. Emittance measurements of the electron beam at the GTF contain evidence of strong coupling between the transverse dimensions of the beam. This thesis explores the effects of this coupling on the determination of the projected emittances of the electron beam. In the presence of such a coupling the projected normalized emittance is no longer a conserved quantity. The conserved quantity is the normalized full four dimensional phase space occupied by the beam. A method to determine the presence and evaluate the strength of the coupling in emittance measurements made in the laboratory is developed. A method to calculate the four dimensional volume the beam occupies in phase space using quantities available in the laboratory environment is also developed. Results of measurements made of the electron beam at the GTF that demonstrate these concepts are presented and discussed.

Evaluation of training nurses to perform semi-automated three-dimensional left ventricular ejection fraction using a customised workstation-based training protocol.

Science.gov (United States)

Guppy-Coles, Kristyan B; Prasad, Sandhir B; Smith, Kym C; Hillier, Samuel; Lo, Ada; Atherton, John J

2015-06-01

We aimed to determine the feasibility of training cardiac nurses to evaluate left ventricular function utilising a semi-automated, workstation-based protocol on three dimensional echocardiography images. Assessment of left ventricular function by nurses is an attractive concept. Recent developments in three dimensional echocardiography coupled with border detection assistance have reduced inter- and intra-observer variability and analysis time. This could allow abbreviated training of nurses to assess cardiac function. A comparative, diagnostic accuracy study evaluating left ventricular ejection fraction assessment utilising a semi-automated, workstation-based protocol performed by echocardiography-naïve nurses on previously acquired three dimensional echocardiography images. Nine cardiac nurses underwent two brief lectures about cardiac anatomy, physiology and three dimensional left ventricular ejection fraction assessment, before a hands-on demonstration in 20 cases. We then selected 50 cases from our three dimensional echocardiography library based on optimal image quality with a broad range of left ventricular ejection fractions, which was quantified by two experienced sonographers and the average used as the comparator for the nurses. Nurses independently measured three dimensional left ventricular ejection fraction using the Auto lvq package with semi-automated border detection. The left ventricular ejection fraction range was 25-72% (70% with a left ventricular ejection fraction nurses showed excellent agreement with the sonographers. Minimal intra-observer variability was noted on both short-term (same day) and long-term (>2 weeks later) retest. It is feasible to train nurses to measure left ventricular ejection fraction utilising a semi-automated, workstation-based protocol on previously acquired three dimensional echocardiography images. Further study is needed to determine the feasibility of training nurses to acquire three dimensional echocardiography

Transesophageal echocardiography in NeoChord procedure

Directory of Open Access Journals (Sweden)

Pittarello Demetrio

2015-01-01

Full Text Available Background: Transapical off-pump mitral valve intervention with neochord implantation for degenerative mitral valve disease have been recently introduced in the surgical practice. The procedure is performed under 2D-3D transesophageal echocardiography guidance. Methods: The use of 3D real-time transesophageal echocardiography provides more accurate information than 2D echocardiography only in all the steps of the procedure. In particular 3D echocardiography is mandatory for preoperative assessment of the morphology of the valve, for correct positioning of the neochord on the diseased segment , for the final tensioning of the chordae and for the final evaluation of the surgical result. Result and Conclusion: This article is to outline the technical aspects of the transesophageal echocardiography guidance of the NeoChord procedure showing that the procedure can be performed only with a close and continuous interaction between the anesthesiologist and the cardiac surgeon.

Determination of the optimum number of cardiac cycles to differentiate intra-pulmonary shunt and patent foramen ovale by saline contrast two- and three-dimensional echocardiography.

Science.gov (United States)

Bhatia, Nirmanmoh; Abushora, Mohannad Y; Donneyong, Macarius M; Stoddard, Marcus F

2014-03-01

Patent foramen ovale (PFO) and intra-pulmonary shunt (IPS) are potential causes of stroke. The most optimum cardiac cycle cutoff for bubbles to appear in the left heart on saline contrast transthoracic echocardiography (TTE) as criteria to differentiate the 2 entities is unknown. Ninety-five adult patients had saline contrast transesophageal echocardiography (TEE), two-dimensional (2D) and 3DTTE. Sensitivity and specificity of each cardiac cycle as cutoff to differentiate a PFO and IPS were obtained. Transesophageal echocardiography showed IPS in 28 and PFO in 15 patients. If bubbles appeared in the left heart within the first 4 cardiac cycles (the 4th cardiac cycle rule) as compared to alternate cutoffs, a PFO was most accurately diagnosed by both 2D and 3DTTE. Bubbles appearing at or after the 5th cardiac cycle most accurately determined an IPS. 3D versus 2DTTE had a trend for a higher sensitivity (61% vs. 36%, P = 0.06), but similar specificity (94% vs. 91%) for IPS. Accuracy of 3DTTE was 84% and 2DTTE was 75% (P = 0.08) for IPS. For PFO, 2DTTE sensitivity (87%) and specificity (98%) did not differ (P = NS) from that of 3DTTE sensitivity (73%) and specificity (100%). This study demonstrates for the first time that the 4th cardiac cycle rule differentiates PFO and IPS most optimally by 2D and 3DTTE. 3DTTE appears to have higher sensitivity for diagnosing IPS. These data suggest that 3DTTE is preferable when IPS is to be diagnosed. Both methods are similar for diagnosing PFO. © 2013, Wiley Periodicals, Inc.

One-way quantum computation with four-dimensional photonic qudits

International Nuclear Information System (INIS)

Joo, Jaewoo; Knight, Peter L.; O'Brien, Jeremy L.; Rudolph, Terry

2007-01-01

We consider the possibility of performing linear optical quantum computations making use of extra photonic degrees of freedom. In particular, we focus on the case where we use photons as quadbits, four-dimensional photonic qudits. The basic 2-quadbit cluster state is a hyperentangled state across polarization and two spatial mode degrees of freedom. We examine the nondeterministic methods whereby such states can be created from single photons and/or Bell pairs and then give some mechanisms for performing higher-dimensional fusion gates

Early Detection of Subclinical Uremic Cardiomyopathy Using Two-Dimensional Speckle Tracking Echocardiography.

Science.gov (United States)

Hassanin, Noha; Alkemary, Alkhateeb

2016-04-01

Overhydration has a deleterious effect on cardio myocytes. This study was designated to evaluate left ventricular (LV) systolic and diastolic dysfunction in patients with various stages of chronic kidney disease (CKD) using conventional, tissue Doppler and two-dimensional speckle tracking echocardiography (2DSTE). Forty controls and 90 CKD patients, aged 49.3 ± 14 years old, were enrolled in the study. Patients were divided into 3 groups depending on their glomerular filtration rate. Group 1 (≥60 mL/min per 1.73 m(2) ), group 2 (≤60 mL/min per 1.73 m(2) ), and group 3 (≤60 mL/min per 1.73 m(2) and on regular dialysis for at least 12 months). Pulsed-Doppler and tissue Doppler studies were used to estimate LV filling pressure E/E'. Using 2DSTE, circumferential, radial, and longitudinal functions of the LV have been measured. LV longitudinal systolic strain, early, and late diastolic strain rates were significantly reduced in CKD patients (-16.9 ± 3.8%, 1.6 ± 0.5%, and 1.3 ± 0.4% in CKD vs. -22.5 ± 0.6%, 2.3 ± 0.2%, and 1.9 ± 0.1% in controls, P < 0.001 for all), and no difference was observed in terms of the circumferential LV functions (-22.4 ± 1.7 vs. -22.5 ± 1.4, P = 0.567). Severity of the kidney dysfunction appears to parallel with the rise of E/E' significantly (P < 0.001). In CKD, although the longitudinal and radial systolic functions were reduced, LV ejection fraction may remain within normal limits due to the preservation of the circumferential functions. Early detection of uremic cardiomyopathy might provide useful information for the risk stratification and decide the proper dialysis therapy in these patients. © 2015, Wiley Periodicals, Inc.

Quantum Mechanics and Black Holes in Four-Dimensional String Theory

CERN Document Server

Ellis, Jonathan Richard; Nanopoulos, Dimitri V

1992-01-01

In previous papers we have shown how strings in a two-dimensional target space reconcile quantum mechanics with general relativity, thanks to an infinite set of conserved quantum numbers, ``W-hair'', associated with topological soliton-like states. In this paper we extend these arguments to four dimensions, by considering explicitly the case of string black holes with radial symmetry. The key infinite-dimensional W-symmetry is associated with the $\\frac{SU(1,1)}{U(1)}$ coset structure of the dilaton-graviton sector that is a model-independent feature of spherically symmetric four-dimensional strings. Arguments are also given that the enormous number of string {\\it discrete (topological)} states account for the maintenance of quantum coherence during the (non-thermal) stringy evaporation process, as well as quenching the large Hawking-Bekenstein entropy associated with the black hole. Defining the latter as the measure of the loss of information for an observer at infinity, who - ignoring the higher string qua...

A novel four-dimensional analytical approach for analysis of complex samples.

Science.gov (United States)

Stephan, Susanne; Jakob, Cornelia; Hippler, Jörg; Schmitz, Oliver J

2016-05-01

A two-dimensional LC (2D-LC) method, based on the work of Erni and Frei in 1978, was developed and coupled to an ion mobility-high-resolution mass spectrometer (IM-MS), which enabled the separation of complex samples in four dimensions (2D-LC, ion mobility spectrometry (IMS), and mass spectrometry (MS)). This approach works as a continuous multiheart-cutting LC system, using a long modulation time of 4 min, which allows the complete transfer of most of the first - dimension peaks to the second - dimension column without fractionation, in comparison to comprehensive two-dimensional liquid chromatography. Hence, each compound delivers only one peak in the second dimension, which simplifies the data handling even when ion mobility spectrometry as a third and mass spectrometry as a fourth dimension are introduced. The analysis of a plant extract from Ginkgo biloba shows the separation power of this four-dimensional separation method with a calculated total peak capacity of more than 8700. Furthermore, the advantage of ion mobility for characterizing unknown compounds by their collision cross section (CCS) and accurate mass in a non-target approach is shown for different matrices like plant extracts and coffee. Graphical abstract Principle of the four-dimensional separation.

New four-dimensional symmetry

International Nuclear Information System (INIS)

Hsu, J.P.

1976-01-01

A new picture of nature is proposed in which there are only two fundamental universal constants anti e (identical with e/c) and dirac constant (identical with dirac constant/c). The theory is developed within the framework of a new four-dimensional symmetry which is constructed on the basis of the Poincare--Einstein principle of relativity for the laws of physics and the Newtonian concept of time. One obtains a new space--light transformation law, a velocity-addition law, and so on. In this symmetry scheme, the speed of light is constant and is completely relative. The new theory is logically self-consistent, and it moreover is in agreement with all previously established experimental facts, such as the ''lifetime dilatation'' of unstable particles, the Michelson--Morley experiment, etc. There is a difference relative to the usual theory, though, in that our theory predicts a new law for the Doppler frequency shift, which can be tested experimentally by measuring the second-order frequency shift

Quantitation of valve regurgitation severity by three-dimensional vena contracta area is superior to flow convergence method of quantitation on transesophageal echocardiography.

Science.gov (United States)

Abudiab, Muaz M; Chao, Chieh-Ju; Liu, Shuang; Naqvi, Tasneem Z

2017-07-01

Quantitation of regurgitation severity using the proximal isovelocity acceleration (PISA) method to calculate effective regurgitant orifice (ERO) area has limitations. Measurement of three-dimensional (3D) vena contracta area (VCA) accurately grades mitral regurgitation (MR) severity on transthoracic echocardiography (TTE). We evaluated 3D VCA quantitation of regurgitant jet severity using 3D transesophageal echocardiography (TEE) in 110 native mitral, aortic, and tricuspid valves and six prosthetic valves in patients with at least mild valvular regurgitation. The ASE-recommended integrative method comprising semiquantitative and quantitative assessment of valvular regurgitation was used as a reference method, including ERO area by 2D PISA for assigning severity of regurgitation grade. Mean age was 62.2±14.4 years; 3D VCA quantitation was feasible in 91% regurgitant valves compared to 78% by the PISA method. When both methods were feasible and in the presence of a single regurgitant jet, 3D VCA and 2D PISA were similar in differentiating assigned severity (ANOVAP<.001). In valves with multiple jets, however, 3D VCA had a better correlation to assigned severity (ANOVAP<.0001). The agreement of 2D PISA and 3D VCA with the integrative method was 47% and 58% for moderate and 65% and 88% for severe regurgitation, respectively. Measurement of 3D VCA by TEE is superior to the 2D PISA method in determination of regurgitation severity in multiple native and prosthetic valves. © 2017, Wiley Periodicals, Inc.

Comparison of Quantitative Wall Motion Analysis and Strain For Detection Of Coronary Stenosis With Three-Dimensional Dobutamine Stress Echocardiography

Science.gov (United States)

Parker, Katherine M.; Clark, Alexander P.; Goodman, Norman C.; Glover, David K.; Holmes, Jeffrey W.

2015-01-01

Background Quantitative analysis of wall motion from three-dimensional (3D) dobutamine stress echocardiography (DSE) could provide additional diagnostic information not available from qualitative analysis. In this study we compare the effectiveness of 3D fractional shortening (3DFS), a measure of wall motion computed from 3D echocardiography (3DE), to strain and strain rate measured with sonomicrometry for detecting critical stenoses during DSE. Methods Eleven open-chest dogs underwent DSE both with and without a critical stenosis. 3DFS was measured from 3DE images acquired at peak stress. 3DFS was normalized by subtracting average 3DFS during control peak stress (Δ3DFS). Strains in the perfusion defect (PD) were measured from sonomicrometry, and PD size and location were measured with microspheres. Results A Δ3DFS abnormality indicated the presence of a critical stenosis with high sensitivity and specificity (88% and 100%, respectively), and Δ3DFS abnormality size correlated with PD size (R2=0.54). The sensitivity and specificity for Δ3DFS was similar to that for area strain (88%, 100%) and circumferential strain and strain rate (88%, 92% and 88%, 86%, respectively), while longitudinal strain and strain rate were less specific. Δ3DFS correlated significantly with both coronary flow reserve (R2=0.71) and PD size (R2=0.97), while area strain correlated with PD size only (R2=0.67), and other measures were not significantly correlated with flow reserve or PD size. Conclusion Quantitative wall motion analysis using Δ3DFS is effective for detecting critical stenoses during DSE, performing similarly to 3D strain, and provides potentially useful information on the size and location of a perfusion defect. PMID:24815588

Four-dimensional anti-de Sitter toroidal black holes from a three-dimensional perspective: Full complexity

International Nuclear Information System (INIS)

Zanchin, Vilson T.; Kleber, Antares; Lemos, Jose P.S.

2002-01-01

The dimensional reduction of black hole solutions in four-dimensional (4D) general relativity is performed and new 3D black hole solutions are obtained. Considering a 4D spacetime with one spacelike Killing vector, it is possible to split the Einstein-Hilbert-Maxwell action with a cosmological term in terms of 3D quantities. Definitions of quasilocal mass and charges in 3D spacetimes are reviewed. The analysis is then particularized to the toroidal charged rotating anti-de Sitter black hole. The reinterpretation of the fields and charges in terms of a three-dimensional point of view is given in each case, and the causal structure analyzed

Ultra high speed optical transmission using subcarrier-multiplexed four-dimensional LDPC-coded modulation.

Science.gov (United States)

Batshon, Hussam G; Djordjevic, Ivan; Schmidt, Ted

2010-09-13

We propose a subcarrier-multiplexed four-dimensional LDPC bit-interleaved coded modulation scheme that is capable of achieving beyond 480 Gb/s single-channel transmission rate over optical channels. Subcarrier-multiplexed four-dimensional LDPC coded modulation scheme outperforms the corresponding dual polarization schemes by up to 4.6 dB in OSNR at BER 10(-8).

Optimal Analysis of Left Atrial Strain by Speckle Tracking Echocardiography: P-wave versus R-wave Trigger.

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Hayashi, Shuji; Yamada, Hirotsugu; Bando, Mika; Saijo, Yoshihito; Nishio, Susumu; Hirata, Yukina; Klein, Allan L; Sata, Masataka

2015-08-01

Left atrial (LA) strain analysis using speckle tracking echocardiography is useful for assessing LA function. However, there is no established procedure for this method. Most investigators have determined the electrocardiographic R-wave peak as the starting point for LA strain analysis. To test our hypothesis that P-wave onset should be used as the starting point, we measured LA strain using 2 different starting points and compared the strain values with the corresponding LA volume indices obtained by three-dimensional (3D) echocardiography. We enrolled 78 subjects (61 ± 17 years, 25 males) with and without various cardiac diseases in this study and assessed global longitudinal LA strain by two-dimensional speckle tracking strain echocardiography using EchoPac software. We used either R-wave peak or P-wave onset as the starting point for determining LA strains during the reservoir (Rres, Pres), conduit (Rcon, Pcon), and booster pump (Rpump, Ppump) phases. We determined the maximum, minimum, and preatrial contraction LA volumes, and calculated the LA total, passive, and active emptying fractions using 3D echocardiography. The correlation between Pres and LA total emptying fraction was better than the correlation between Rres and LA total emptying fraction (r = 0.458 vs. 0.308, P = 0.026). Pcon and Ppump exhibited better correlation with the corresponding 3D echocardiographic parameters than Rcon (r = 0.560 vs. 0.479, P = 0.133) and Rpump (r = 0.577 vs. 0.345, P = 0.003), respectively. LA strain in any phase should be analyzed using P-wave onset as the starting point rather than R-wave peak. © 2014, Wiley Periodicals, Inc.

Abnormal biventricular performance in asymptomatic adolescents late after repaired Tetralogy of Fallot: Combined two-dimensional speckle tracking and three-dimensional echocardiography study

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Ken-Pen Weng

2018-02-01

Conclusion: Our results suggest asymptomatic adolescents with repaired TOF had abnormal biventricular myocardial performance, as demonstrated by combined 2D speckle-tracking and 3D echocardiography. The implications of these findings for management of adolescents late after repaired TOF remain to be determined.

Real-time three-dimensional transesophageal echocardiography in the assessment of mechanical prosthetic mitral valve ring thrombosis.

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Ozkan, Mehmet; Gürsoy, Ozan Mustafa; Astarcıoğlu, Mehmet Ali; Gündüz, Sabahattin; Cakal, Beytullah; Karakoyun, Süleyman; Kalçık, Macit; Kahveci, Gökhan; Duran, Nilüfer Ekşi; Yıldız, Mustafa; Cevik, Cihan

2013-10-01

Although 2-dimensional (2D) transesophageal echocardiography (TEE) is the gold standard for the diagnosis of prosthetic valve thrombosis, nonobstructive clots located on mitral valve rings can be missed. Real-time 3-dimensional (3D) TEE has incremental value in the visualization of mitral prosthesis. The aim of this study was to investigate the utility of real-time 3D TEE in the diagnosis of mitral prosthetic ring thrombosis. The clinical outcomes of these patients in relation to real-time 3D transesophageal echocardiographic findings were analyzed. Of 1,263 patients who underwent echocardiographic studies, 174 patients (37 men, 137 women) with mitral ring thrombosis detected by real-time 3D TEE constituted the main study population. Patients were followed prospectively on oral anticoagulation for 25 ± 7 months. Eighty-nine patients (51%) had thrombi that were missed on 2D TEE and depicted only on real-time 3D TEE. The remaining cases were partially visualized with 2D TEE but completely visualized with real-time 3D TEE. Thirty-seven patients (21%) had thromboembolism. The mean thickness of the ring thrombosis in patients with thromboembolism was greater than that in patients without thromboembolism (3.8 ± 0.9 vs 2.8 ± 0.7 mm, p 3D TEE during follow-up. There were no thrombi in 39 patients (25%); 45 (29%) had regression of thrombi, and there was no change in thrombus size in 68 patients (44%). Thrombus size increased in 3 patients (2%). Thrombosis was confirmed surgically and histopathologically in 12 patients (7%). In conclusion, real-time 3D TEE can detect prosthetic mitral ring thrombosis that could be missed on 2D TEE and cause thromboembolic events. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of right atrial dysfunction in patients with corrected tetralogy of Fallot using 3D speckle-tracking echocardiography. Insights from the CSONGRAD Registry and MAGYAR-Path Study.

Science.gov (United States)

Nemes, Attila; Havasi, Kálmán; Domsik, Péter; Kalapos, Anita; Forster, Tamás

2015-11-01

In recent studies, alterations in ventricular deformations were demonstrated in adult patients with corrected tetralogy of Fallot by three-dimensional speckle-tracking echocardiography. The present study was designed to assess three-dimensional speckle-tracking echocardiography-derived right atrial volumetric and strain parameters in corrected tetralogy of Fallot. A total of 17 patients with corrected tetralogy of Fallot were included in the study. Their results were compared with 18 age- and gender-matched healthy controls. Complete two-dimensional echocardiography and three-dimensional speckle-tracking echocardiography were performed in all cases. Significantly increased right atrial volumes respecting heart cycle were detected in patients with corrected tetralogy of Fallot. Total and passive atrial emptying fractions proved to be significantly decreased in patients with corrected tetralogy of Fallot (26.4 ± 12.4 % vs. 39.1 ± 8.8 %, p = 0.001 and 11.2 ± 6.8 % vs. 19.8 ± 9.0 %, p = 0.003, respectively). Global and mean segmental peak longitudinal (17.3 ± 9.2 % vs. 30.8 ± 11.2 %, p = 0.0007 and 20.6 ± 10.7 % vs. 34.4 ± 10.5 %, p = 0.0005) and area strains (20.1 ± 17.6 % vs. 41.0 ± 19.8 %, p = 0.004 and 28.1 ± 19.8 % vs. 49.1 ± 19.7 %, p = 0.004) as well as global radial peak strain (-9.1 ± 5.1 % vs. -15.0 ± 10.0 %, p = 0.05) were reduced in patients with corrected tetralogy of Fallot compared with controls. The complexity of right atrial dysfunction can be demonstrated by three-dimensional speckle-tracking echocardiography in patients with corrected tetralogy of Fallot.

Prediction of wall motion improvement after coronary revascularization in patients with postmyocardial infarction. Diagnostic value of dobutamine stress echocardiography and myocardial contrast echocardiography

International Nuclear Information System (INIS)

Waku, Sachiko; Ohkubo, Tomoyuki; Takada, Kiyoshi; Ishihara, Tadashi; Ohsawa, Nakaaki; Adachi, Itaru; Narabayashi, Isamu

1997-01-01

The diagnostic value of dobutamine stress echocardiography, myocardial contrast echocardiography and dipyridamole stress thallium-201 single photon emission computed tomography (SPECT) for predicting recovery of wall motion abnormality after revascularization was evaluated in 13 patients with postmyocardial infarction. Seventeen segments showed severe wall motion abnormalities before revascularization. Nine segments which had relatively good Tl uptake on delayed SPECT images despite severely abnormal wall motion were opacified during myocardial contrast echocardiography, and showed improved wall motion after revascularization. In contrast, three segments which had poor Tl uptake and severely abnormal wall motion were not opacified during myocardial contrast echocardiography, and showed no improvement in wall motion during dobutamine stress echocardiography and after revascularization. The following three findings were assumed to be signs of myocardial viability: good Tl uptake on delayed SPECT images, improved wall motion by dobutamine stress echocardiography, and positive opacification of the myocardium by myocardiai contrast echocardiography. Myocardial contrast echocardiography had the highest sensitivity (100%) and negative predictive value (100%). Delayed SPECT images had the highest specificity (100%) and positive predictive value (100%). Dobutamine stress echocardiography had a sensitivity of 83.0%, specificity of 80.0%, positive predictive value of 90.9%, and negative predictive value of 66.7%, respectively. Myocardial contrast echocardiography showed the lowest specificity (60.0%). The techniques of dobutamine stress echocardiography and SPECT, though noninvasive, may underestimate wall motion improvement after revascularization. Further examination by myocardial contrast echocardiography is recommended to assess myocardial viability for determining the indications for coronary revascularization in spite of its invasiveness. (author)

Fetal Echocardiography/Your Unborn Baby's Heart

Science.gov (United States)

... Artery Disease Venous Thromboembolism Aortic Aneurysm More Fetal Echocardiography / Your Unborn Baby's Heart Updated:Oct 6,2016 ... Your Risk • Symptoms & Diagnosis Introduction Common Tests Fetal Echocardiography/Your Unborn Baby's Heart - Fetal Echocardiogram Test - Detection ...

Normal references of right ventricular strain values by two-dimensional strain echocardiography according to the age and gender.

Science.gov (United States)

Park, Jae-Hyeong; Choi, Jin-Oh; Park, Seung Woo; Cho, Goo-Yeong; Oh, Jin Kyung; Lee, Jae-Hwan; Seong, In-Whan

2018-02-01

Right ventricular (RV) strain values by 2-dimensional strain echocardiography (STE) can be used as objective markers of RV systolic function. However, there is little data about normal reference RV strain values according to age and gender. We measured normal RV strain values by STE. RV strain values were analyzed from the digitally stored echocardiographic images from NORMAL (Normal echOcardiogRaphic diMensions and functions in KoreAn popuLation) study for the measurement of normal echocardiographic values performed in 23 Korean university hospitals. We enrolled total 1003 healthy persons in the NORMAL study. Of them, we analyzed 2-dimensional RV strain values in 493 subjects (261 females, mean 47 ± 15 years old) only with echocardiographic images by GE machines. Their LV systolic and diastolic functions were normal. RV fractional area change was 48 ± 6% and tricuspid annular plane systolic excursion was 23 ± 3 mm. Total RV global longitudinal peak systolic strain (RVGLS total ) was -21.5 ± 3.2%. Females had higher absolute RVGLS total (-22.3 ± 3.3 vs -20.7 ± 2.9%, p value to that of older males (age ≥50 years, -20.5 ± 2.8 vs -20.9 ± 3.1%, p = 0.224). We calculated normal RVGLS values in normal population. Females have higher absolute strain values than males, especially in younger age groups (<50 years old).

Energy analysis of four dimensional extended hyperbolic Scarf I plus three dimensional separable trigonometric noncentral potentials using SUSY QM approach

International Nuclear Information System (INIS)

Suparmi, A.; Cari, C.; Deta, U. A.; Handhika, J.

2016-01-01

The non-relativistic energies and wave functions of extended hyperbolic Scarf I plus separable non-central shape invariant potential in four dimensions are investigated using Supersymmetric Quantum Mechanics (SUSY QM) Approach. The three dimensional separable non-central shape invariant angular potential consists of trigonometric Scarf II, Manning Rosen and Poschl-Teller potentials. The four dimensional Schrodinger equation with separable shape invariant non-central potential is reduced into four one dimensional Schrodinger equations through variable separation method. By using SUSY QM, the non-relativistic energies and radial wave functions are obtained from radial Schrodinger equation, the orbital quantum numbers and angular wave functions are obtained from angular Schrodinger equations. The extended potential means there is perturbation terms in potential and cause the decrease in energy spectra of Scarf I potential. (paper)

[Assessment of the right ventricular function in healthy volunteers with one beat full-volume real-time three-dimensional echocardiography].

Science.gov (United States)

Zhu, Wei-hong; Zhang, Jin; Tong, Kai; Zhi, Guang; He, Kun-lun

2012-08-01

To determine the normal value of right ventricle using one beat full-volume real-time three-dimensional echocardiography (RT-3DE) and assess the feasibility of this technique. One beat full volume images were acquired at the apical 4 chamber view in 129 healthy volunteers. The right and left ventricular volumes were examined with the eSie LVA and RVA. The subjects were divided into 2 gender groups (male and female) and 3 age groups (20 - 39 years old, 40 - 59 years old, 60 years old and above). Adequate data were obtained in 129 subjects. The RV-EDV was (92.4 ± 21.3) ml, RV-ESV (34.6 ± 9.2) ml, RV-SV (57.8 ± 13.9) ml, RV-EF (62.5 ± 5.0) ml. EDV, ESV, and EF were significant different while SV was similar between RV and LV (all P Right ventricle function can be measured noninvasively by RT-3DE with high feasibility. This novel method contributes to the detailed study of right heart function in various cardiovascular diseases.

Safety of ultrasound contrast agents in stress echocardiography.

Science.gov (United States)

Gabriel, Ruvin S; Smyth, Yvonne M; Menon, Venu; Klein, Allan L; Grimm, Richard A; Thomas, James D; Sabik, Ellen Mayer

2008-11-01

Definity and Optison are perflutren-based ultrasound contrast agents used in echocardiography. United States Food and Drug Administration warnings regarding serious cardiopulmonary reactions and death after Definity administration highlighted the limited safety data in patients who undergo contrast stress echocardiography. From 1998 and 2007, 2,022 patients underwent dobutamine stress echocardiography and 2,764 underwent exercise stress echocardiography with contrast at the Cleveland Clinic. The echocardiographic database, patient records, and the Social Security Death Index were reviewed for the timing and cause of death, severe adverse events, arrhythmias, and symptoms. Complication rates for contrast dobutamine stress echocardiography and exercise stress echocardiography were compared with those in a control group of 5,012 patients matched for test year and type who did not receive contrast. Ninety-five percent of studies were performed in outpatients. There were no differences in the rates of severe adverse events (0.19% vs 0.17%, p = 0.7), death within 24 hours (0% vs 0.04%, p = 0.1), cardiac arrest (0.04% vs 0.04%, p = 0.96), and sustained ventricular tachycardia (0.2% vs 0.1%, p = 0.32) between patients receiving and not receiving intravenous contrast, respectively. In conclusion, severe adverse reactions to intravenous contrast agents during stress echocardiography are uncommon. Contrast use does not add to the baseline risk for severe adverse events in patients who undergo stress echocardiography.

Nonrenormalizable quantum field models in four-dimensional space-time

International Nuclear Information System (INIS)

Raczka, R.

1978-01-01

The construction of no-cutoff Euclidean Green's functions for nonrenormalizable interactions L/sub I/(phi) = lambda∫ddelta (epsilon): expepsilonphi: in four-dimensional space-time is carried out. It is shown that all axioms for the generating functional of the Euclidean Green's function are satisfied except perhaps SO(4) invariance

Four-dimensional Hooke's law can encompass linear elasticity and inertia

International Nuclear Information System (INIS)

Antoci, S.; Mihich, L.

1999-01-01

The question is examined whether the formally straightforward extension of Hooke's time-honoured stress-strain relation to the four dimensions of special and of general relativity can make physical sense. The four-dimensional Hooke law is found able to account for the inertia of matter; in the flat-space, slow-motion approximation the field equations for the displacement four-vector field ξ i can encompass both linear elasticity and inertia. In this limit one just recovers the equations of motion of the classical theory of elasticity

A covariant form of the Maxwell's equations in four-dimensional spaces with an arbitrary signature

International Nuclear Information System (INIS)

Lukac, I.

1991-01-01

The concept of duality in the four-dimensional spaces with the arbitrary constant metric is strictly mathematically formulated. A covariant model for covariant and contravariant bivectors in this space based on three four-dimensional vectors is proposed. 14 refs

Quantum walk with a four-dimensional coin

International Nuclear Information System (INIS)

Hamilton, Craig S; Gabris, Aurel; Jex, Igor; Barnett, Stephen M

2011-01-01

We examine the physical implementation of a discrete time quantum walk with a four-dimensional coin. Our quantum walker is a photon moving repeatedly through a time delay loop, with time being our position space. The quantum coin is implemented using the internal states of the photon: the polarization and two of the orbital angular momentum states. We demonstrate how to implement this physically and what components would be needed. We then illustrate some of the results that could be obtained by performing the experiment.

Right ventricle performances with echocardiography and 99mTc myocardial perfusion imaging in pulmonary arterial hypertension patients.

Science.gov (United States)

Liu, Jie; Fei, Lei; Huang, Guang-Qing; Shang, Xiao-Ke; Liu, Mei; Pei, Zhi-Jun; Zhang, Yong-Xue

2018-05-01

Right heart catheterization is commonly used to measure right ventricle hemodynamic parameters and is the gold standard for pulmonary arterial hypertension diagnosis; however, it is not suitable for patients' long-term follow-up. Non-invasive echocardiography and nuclear medicine have been applied to measure right ventricle anatomy and function, but the guidelines for the usefulness of clinical parameters remain to be established. The goal of this study is to identify reliable clinical parameters of right ventricle function in pulmonary arterial hypertension patients and analyze the relationship of these clinical parameters with the disease severity of pulmonary arterial hypertension. In this study, 23 normal subjects and 23 pulmonary arterial hypertension patients were recruited from January 2015 to March 2016. Pulmonary arterial hypertension patients were classified into moderate and severe pulmonary arterial hypertension groups according to their mean pulmonary arterial pressure levels. All the subjects were subjected to physical examination, chest X-ray, 12-lead electrocardiogram, right heart catheterization, two-dimensional echocardiography, and technetium 99m ( 99m Tc) myocardial perfusion imaging. Compared to normal subjects, the right heart catheterization indexes including right ventricle systolic pressure, right ventricle end diastolic pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, pulmonary vascular resistance, and right ventricle end systolic pressure increased in pulmonary arterial hypertension patients and were correlated with mean pulmonary arterial pressure levels. Echocardiography parameters, including tricuspid regurgitation peak velocity, tricuspid regurgitation pressure gradient, tricuspid annular plane systolic excursion and fractional area, right ventricle-myocardial performance index, were significantly associated with the mean pulmonary arterial pressure levels in pulmonary arterial hypertension patients

The Evolutionary Development of Echocardiography

Science.gov (United States)

Maleki, Majid; Esmaeilzadeh, Maryam

2012-01-01

Echocardiography is a non-invasive diagnostic technique which provides information on cardiac morphology, function, and hemodynamics. It is the most frequently used cardiovascular diagnostic test only after electrocardiography. In less than five decades, the evolution in this technique has made it the basic part of cardiovascular medicine. Herein, the evolution of various forms of echocardiography is briefly described. PMID:23390327

Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats

Directory of Open Access Journals (Sweden)

Nozawa E.

2006-01-01

Full Text Available Although echocardiography has been used in rats, few studies have determined its efficacy for estimating myocardial infarct size. Our objective was to estimate the myocardial infarct size, and to evaluate anatomic and functional variables of the left ventricle. Myocardial infarction was produced in 43 female Wistar rats by ligature of the left coronary artery. Echocardiography was performed 5 weeks later to measure left ventricular diameter and transverse area (mean of 3 transverse planes, infarct size (percentage of the arc with infarct on 3 transverse planes, systolic function by the change in fractional area, and diastolic function by mitral inflow parameters. The histologic measurement of myocardial infarction size was similar to the echocardiographic method. Myocardial infarct size ranged from 4.8 to 66.6% when determined by histology and from 5 to 69.8% when determined by echocardiography, with good correlation (r = 0.88; P < 0.05; Pearson correlation coefficient. Left ventricular diameter and mean diastolic transverse area correlated with myocardial infarct size by histology (r = 0.57 and r = 0.78; P < 0.0005. The fractional area change ranged from 28.5 ± 5.6 (large-size myocardial infarction to 53.1 ± 1.5% (control and correlated with myocardial infarct size by echocardiography (r = -0.87; P < 0.00001 and histology (r = -0.78; P < 00001. The E/A wave ratio of mitral inflow velocity for animals with large-size myocardial infarction (5.6 ± 2.7 was significantly higher than for all others (control: 1.9 ± 0.1; small-size myocardial infarction: 1.9 ± 0.4; moderate-size myocardial infarction: 2.8 ± 2.3. There was good agreement between echocardiographic and histologic estimates of myocardial infarct size in rats.

Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart.

Science.gov (United States)

Yeo, Lami; Romero, Roberto

2013-09-01

To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology. We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum). In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy. The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify

Implementation of the stress echocardiography in an echocardiographic laboratory

International Nuclear Information System (INIS)

Solis Brizuela, Felix

2013-01-01

The logistics for the implementation of the stress echocardiography is defined with based on current recommendations, for an echocardiography laboratory. The protocols established to perform the studies and procedures of this diagnostic method are exposed. The elementary conditions to realize with safety the stress echocardiography are established. Recent literature on the evaluation of new echocardiographic techniques is reviewed to determine their usefulness in stress testing. The assessment of stress echocardiography is developed. The stress echocardiography has been the procedure with high sensitivity and specificity for the diagnosis of coronary artery disease [es

Four-Dimensional Ultrafast Electron Microscopy: Insights into an Emerging Technique

KAUST Repository

Adhikari, Aniruddha; Eliason, Jeffrey K.; Sun, Jingya; Bose, Riya; Flannigan, David J.; Mohammed, Omar F.

2016-01-01

Four-dimensional ultrafast electron microscopy (4D-UEM) is a novel analytical technique that aims to fulfill the long-held dream of researchers to investigate materials at extremely short spatial and temporal resolutions by integrating the excellent

Three-dimensional echocardiography in various types of heart disease: a comparison study of magnetic resonance imaging and 64-slice computed tomography in a real-world population.

Science.gov (United States)

Squeri, Angelo; Censi, Stefano; Reverberi, Claudio; Gaibazzi, Nicola; Baldelli, Marco; Binno, Simone Maurizio; Properzi, Enrico; Bosi, Stefano

2017-03-01

Accurate quantification of left ventricular (LV) volumes [end-diastolic volume (EDV) and end-systolic volume (ESV)] and ejection fraction (EF) is of critical importance. The development of real-time three-dimensional echocardiography (RT3DE) has shown better correlation than two-dimensional (2D) echocardiography with magnetic resonance imaging (MRI) measurements. The aim of our study was to assess the accuracy of RT3DE and 64-slice computed tomography (CT) in the evaluation of LV volumes and function using MRI as the reference standard in a real-world population with various types of heart disease with different chamber geometry. The study population consisted of 66 patients referred for cardiac MRI for various pathologies. All patients underwent cardiac MRI, and RT3DE and 64 slices CT were then performed on a subsequent day. The study population was then divided into 5 clinical groups depending on the underlying heart disease. RT3DE volumes correlated well with MRI values (R 2 values: 0.90 for EDV and 0.94 for ESV). RT3DE measurements of EF correlated well with MRI values (R 2  = 0.86). RT3DE measurements resulted in slightly underestimated values of both EDV and ESV, as reflected by biases of -9.18 and -4.50 mL, respectively. Comparison of RT3DE and MRI in various types of cardiomyopathies showed no statistical difference between different LV geometrical patterns. These results confirm that RT3DE has good accuracy in everyday clinical practice and can be of clinical utility in all types of cardiomyopathy independently of LV geometric pattern, LV diameter or wall thickness, taking into account a slight underestimation of LV volumes and EF compared to MRI.

Practical guidance for the implementation of stress echocardiography.

Science.gov (United States)

Suzuki, Kengo; Hirano, Yutaka; Yamada, Hirotsugu; Murata, Mitsushige; Daimon, Masao; Takeuchi, Masaaki; Seo, Yoshihiro; Izumi, Chisato; Akaishi, Makoto

2018-06-06

Exercise stress testing has been widely undertaken for the diagnosis of heart diseases. The accurate assessment of clinical conditions can be conducted by comparing the findings obtained from the results of stress echocardiography with the changes in the blood/heart rate and electrocardiograms. Numerous overseas studies have reported the utility of stress echocardiography in diagnosing myocardial ischemia; in Japan, the use of this modality for this purpose was included in the national health insurance reimbursable list in 2012. Nevertheless, stress echocardiography is far from being a widespread practice in Japan. This might be due to insufficient equipment (e.g., ergometers, space for test implementation) at each medical institution, shortage of technicians and sonographers who are well experienced and who are responsible for obtaining images during stress testing. The other possible reasons include the limited evidence available in Japan and the lack of a standardized testing protocol. Further dissemination of the practice of exercise stress echocardiography in this country is deemed necessary to establish satisfactory evidence for the use of stress echocardiography in the Japanese population. To this end, efforts are underway to develop a standardized protocol and report format to be adopted throughout Japan. We here present a guideline created by the Guideline Development Committee of the Japanese Society of Echocardiography that describes safe and effective stress echocardiography protocols and report formats. The readers are encouraged to perform exercise stress echocardiography using the proposed template for consensus document and report attached to this guideline.

Measurement of cardiac dimensions with two-dimensional echocardiography in the living horse

International Nuclear Information System (INIS)

Voros, K.; Holmes, J.R.; Gibbs, C.

1991-01-01

Two-dimensional echocardiography (2DE) was performed on 22 unsedated Thoroughbred and part Thoroughbred horses weighing between 411 and 650 kg to establish normal reference values for 2DE measurements. Animals stood during examinations performed with a 3.5 MHz mechanical sector transducer using various transducer positions and tomographic planes. Right ventricular diameter (RVD), ventricular septal thickness (VSTh), aortic diameter (AoD), area of the chordal lumen of the left ventricle (CTA), left ventricular diameter (LVD) and left atrial diameter (LAD) were determined at ventricular end-diastole (Ed) and/or end-systole (Es). Fractional shortening (FS) of the left ventricle and end-systolic left atrial to aortic ratio (LADEs: AoD-Es) also were calculated. Echocardiographic data were related to body weight by linear regression analysis. Intra-observer variability was checked in five horses by measuring each parameter during each of 10 consecutive cardiac cycles. The 2DE data were compared with M-mode values in published reports. In the 18 horses whose weight did not exceed 551 kg, repeatable recordings of good quality were obtained, and 2DE measurements could be made using intra-cardiac reference points. Increasing body weight proved to impose substantial limitations on measurements taken with the available machine and transducer. This problem might be overcome by using probes of lower frequency or equipment with higher quality image display at greater depth. The following parameters correlated significantly to body weight: VSTh-Es (r = 0.69; P<0.01). AoD-Es (r = 0.64; P<0.01) and CTA-Es (r = 0.84; P<0.001). However, technical limitations prevented determination of the relationship between bodyweight and CTA-Ed and LVD-Ed. For each parameter, good reproducibility of values was found because the mean coefficient of variation (CV) varied between 2.6 and 7.2. In this study, 2DE provided reliable qualitative and quantitative assessment of cardiac anatomy and function

Charged rotating black holes in four-dimensional gauged and ungauged supergravities

International Nuclear Information System (INIS)

Chong, Z.-W.; Cvetic, M.; Lue, H.; Pope, C.N.

2005-01-01

We study four-dimensional non-extremal charged rotating black holes in ungauged and gauged supergravity. In the ungauged case, we obtain rotating black holes with four independent charges, as solutions of N=2 supergravity coupled to three Abelian vector multiplets. This is done by reducing the theory along the time direction to three dimensions, where it has an O(4,4) global symmetry. Applied to the reduction of the uncharged Kerr metric, O(1,1) 4 is a subject of O(4,4) transformations generate new solutions that correspond, after lifting back to four dimensions, to the introduction of four independent electromagnetic charges. In the case where these charges are set pairwise equal, we then generalise the four-dimensional rotating black holes to solutions of gauged N=4 supergravity, with mass, angular momentum and two independent electromagnetic charges. The dilaton and axion fields are non-constant. We also find generalisations of the gauged and ungauged solutions to include the NUT parameter, and for the ungauged solutions, the acceleration parameter too. The solutions in gauged supergravity provide new gravitational backgrounds for a further study of the AdS 4 /CFT 3 correspondence at non-zero temperature

Naked singularities in four-dimensional string backgrounds

International Nuclear Information System (INIS)

Mohammedi, N.

1993-04-01

It is shown that gauged nonlinear sigma models can be always deformed by terms proportional to the field strength of the gauge fields (nonminimal gauging). These deformations can be interpreted as perturbations, by marginal operators, of conformal coset models. When applied to the SL(2, R)xSU(2)/U(1)xU(1)) WZWN model, a large class of four-dimensional curved spacetime backgrounds are obtained. In particular, a naked singularity may form at a time when the volume of the universe is different from zero. (orig.)

Carcinoid syndrome diagnosed by echocardiography.

Science.gov (United States)

Garg, Scot; Bourantas, Christos V; Nair, Rajesh K; Alamgir, Farqad

2011-02-17

Right heart failure is a common presentation to both general physicians and cardiologists. Echocardiography is a useful investigation, and usually imaging of the liver is confined to helping estimate the right atrial pressure. We report a case of right heart failure where incidental imaging of the liver architecture during transoesophageal echocardiography helped in establishing the final diagnosis. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Use of real-time three-dimensional transesophageal echocardiography in type A aortic dissections: Advantages of 3D TEE illustrated in three cases

Directory of Open Access Journals (Sweden)

Cindy J Wang

2015-01-01

Full Text Available Stanford type A aortic dissections often present to the hospital requiring emergent surgical intervention. Initial diagnosis is usually made by computed tomography; however transesophageal echocardiography (TEE can further characterize aortic dissections with specific advantages: It may be performed on an unstable patient, it can be used intra-operatively, and it has the ability to provide continuous real-time information. Three-dimensional (3D TEE has become more accessible over recent years allowing it to serve as an additional tool in the operating room. We present a case series of three patients presenting with type A aortic dissections and the advantages of intra-operative 3D TEE to diagnose the extent of dissection in each case. Prior case reports have demonstrated the use of 3D TEE in type A aortic dissections to characterize the extent of dissection and involvement of neighboring structures. In our three cases described, 3D TEE provided additional understanding of spatial relationships between the dissection flap and neighboring structures such as the aortic valve and coronary orifices that were not fully appreciated with two-dimensional TEE, which affected surgical decisions in the operating room. This case series demonstrates the utility and benefit of real-time 3D TEE during intra-operative management of a type A aortic dissection.

Finite-temperature symmetry restoration in the four-dimensional Φ4 model with four components

International Nuclear Information System (INIS)

Jansen, K.

1990-01-01

The finite-temperature symmetry restoration in the four-dimensional φ 4 theory with four components and with an infinite self-coupling is studied by means of Monte Carlo simulations on lattices with time extensions L t =4,5,6 and space extensions 12 3 -28 3 . The numerical calculations are done by means of the Wolff cluster algorithm which is very efficient for simulations near a phase transition. The numerical results are in good agreement with an improved one-loop expansion and with the 1/N-expansion, indicating that in the electroweak theory the symmetry restoration temperature T sr is about 350 GeV. (orig.)

Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography.

Science.gov (United States)

Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas; Andersen, Mads J; Vejlstrup, Niels; Kelbæk, Henning; Engstrøm, Thomas; Møller, Jacob E; Kofoed, Klaus F

2012-06-01

Measurement of left atrial (LA) maximal volume (LA(max)) using two-dimensional transthoracic echocardiography (TTE) provides prognostic information in several cardiac diseases. However, the relationship between LA(max) and LA function is poorly understood and TTE is less well suited for measuring dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir volume) and pump function (left atrial ejection fraction-LAEF) were derived using CMR and MSCT. Left atrial fractional change and left atrial ejection fraction (LAEF) determined with CMR and MSCT were unrelated to LA(max) enlargement by echocardiography (P = NS). There was an overall good agreement between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P fractional change and LAEF is not significantly related to LA(max) measured by TTE. TTE systematically underestimated LA volumes, whereas there are good agreements between MSCT and CMR for volumetric and functional properties.

Stable de Sitter vacua in four-dimensional supergravity originating from five dimensions

International Nuclear Information System (INIS)

Oegetbil, O.

2008-01-01

The five-dimensional stable de Sitter ground states in N=2 supergravity obtained by gauging SO(1,1) symmetry of the real symmetric scalar manifold (in particular, a generic Jordan family manifold of the vector multiplets) simultaneously with a subgroup R s of the R-symmetry group descend to four-dimensional de Sitter ground states under certain conditions. First, the holomorphic section in four dimensions has to be chosen carefully by using the symplectic freedom in four dimensions; second, a group contraction is necessary to bring the potential into a desired form. Under these conditions, stable de Sitter vacua can be obtained in dimensionally reduced theories (from 5D to 4D) if the semidirect product of SO(1,1) with R (1,1) together with a simultaneous R s is gauged. We review the stable de Sitter vacua in four dimensions found in earlier literature for N=2 Yang-Mills Einstein supergravity with the SO(2,1)xR s gauge group in a symplectic basis that comes naturally after dimensional reduction. Although this particular gauge group does not descend directly from five dimensions, we show that its contraction does. Hence, two different theories overlap in certain limits. Examples of stable de Sitter vacua are given for the cases: (i) R s =U(1) R , (ii) R s =SU(2) R , and (iii) N=2 Yang-Mills/Einstein supergravity theory coupled to a universal hypermultiplet. We conclude with a discussion regarding the extension of our results to supergravity theories with more general homogeneous scalar manifolds.

Supergravity duals of supersymmetric four dimensional gauge theories

Energy Technology Data Exchange (ETDEWEB)

Bigazzi, F [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Cotrone, A L [Centre de Physique Theorique, Ecole Polytechnique, Palaiseau Cedex (France); [INFN, Rome (Italy); Petrini, M [Centre de Physique Theorique, Ecole Polytechnique, Palaiseau (France); Zaffaroni, A [Universita di Milano-Bicocca and INFN, Milan (Italy)

2002-03-01

This article contains an overview of some recent attempts of understanding supergravity and string duals of four dimensional gauge theories using the AdS/CFT correspondence. We discuss the general philosophy underlying the various ways to realize Super Yang-Mills theories in terms of systems of branes. We then review some of the existing duals for N=2 and N=1 theories. We also discuss differences and similarities with realistic theories. (author)

Real-time three-dimensional transesophageal echocardiography in valve disease: comparison with surgical findings and evaluation of prosthetic valves.

Science.gov (United States)

Sugeng, Lissa; Shernan, Stanton K; Weinert, Lynn; Shook, Doug; Raman, Jai; Jeevanandam, Valluvan; DuPont, Frank; Fox, John; Mor-Avi, Victor; Lang, Roberto M

2008-12-01

Recently, a novel real-time 3-dimensional (3D) matrix-array transesophageal echocardiographic (3D-MTEE) probe was found to be highly effective in the evaluation of native mitral valves (MVs) and other intracardiac structures, including the interatrial septum and left atrial appendage. However, the ability to visualize prosthetic valves using this transducer has not been evaluated. Moreover, the diagnostic accuracy of this new technology has never been validated against surgical findings. This study was designed to (1) assess the quality of 3D-MTEE images of prosthetic valves and (2) determine the potential value of 3D-MTEE imaging in the preoperative assessment of valvular pathology by comparing images with surgical findings. Eighty-seven patients undergoing clinically indicated transesophageal echocardiography were studied. In 40 patients, 3D-MTEE images of prosthetic MVs, aortic valves (AVs), and tricuspid valves (TVs) were scored for the quality of visualization. For both MVs and AVs, mechanical and bioprosthetic valves, the rings and leaflets were scored individually. In 47 additional patients, intraoperative 3D-MTEE diagnoses of MV pathology obtained before initiating cardiopulmonary bypass were compared with surgical findings. For the visualization of prosthetic MVs and annuloplasty rings, quality was superior compared with AV and TV prostheses. In addition, 3D-MTEE imaging had 96% agreement with surgical findings. Three-dimensional matrix-array transesophageal echocardiographic imaging provides superb imaging and accurate presurgical evaluation of native MV pathology and prostheses. However, the current technology is less accurate for the clinical assessment of AVs and TVs. Fast acquisition and immediate online display will make this the modality of choice for MV surgical planning and postsurgical follow-up.

Endocarditis : Effects of routine echocardiography during Gram-positive bacteraemia

NARCIS (Netherlands)

Vos, F J; Bleeker-Rovers, C P; Sturm, P D; Krabbe, P F M; van Dijk, A P J; Oyen, W J G; Kullberg, B J

2011-01-01

BACKGROUND: Despite firm recommendations to perform echocardiography in high-risk patients with Gram-positive bacteraemia, routine echocardiography is not embedded in daily practice in many settings. The aim of this study was to evaluate whether a regime including routine echocardiography results in

Application of Echocardiography on Transgenic Mice with Cardiomyopathies

Directory of Open Access Journals (Sweden)

G. Chen

2012-01-01

Full Text Available Cardiomyopathies are common cardiac disorders that primarily affect cardiac muscle resulting in cardiac dysfunction and heart failure. Transgenic mouse disease models have been developed to investigate the cellular mechanisms underlying heart failure and sudden cardiac death observed in cardiomyopathy cases and to explore the therapeutic outcomes in experimental animals in vivo. Echocardiography is an essential diagnostic tool for accurate and noninvasive assessment of cardiac structure and function in experimental animals. Our laboratory has been among the first to apply high-frequency research echocardiography on transgenic mice with cardiomyopathies. In this work, we have summarized our and other studies on assessment of systolic and diastolic dysfunction using conventional echocardiography, pulsed Doppler, and tissue Doppler imaging in transgenic mice with various cardiomyopathies. Estimation of embryonic mouse hearts has been performed as well using this high-resolution echocardiography. Some technical considerations in mouse echocardiography have also been discussed.

Improvement of continuous subcutaneous insulin infusion on patients with type 2 diabetes mellitus by 3-dimensional speckle tracking echocardiography.

Science.gov (United States)

Luo, Hong-Xia; Zhou, Xiao-Ling; Kou, Hong-Ju; Ni, Xian-Wei; Wu, Qing; Zou, Chun-Peng; Wu, Dao-Zhu; Liu, Yong-Fang

2018-03-01

Three-dimensional speckle tracking echocardiography (3D-STE) was used to evaluate the improvement of continuous subcutaneous insulin infusion on the left ventricular (LV) systolic function of patients with type 2 diabetes mellitu (T2DM). We recruited T2DM patients (38 cases, diabetic group) and healthy volunteers (35 cases, control group) to collect LV full volume imaging. TomTec software was used for calculating LV global longitudinal strain (LVGLS), global circumferential strain (LVGCS), peak twist (LVTW), peak apical rotation (LVPAR), ejection fraction (LVEF), and torsion (LVT). All indices were re-tested 2 weeks later after intensive treatment of insulin pump. LVGLS, LVGCS, LVTW and LVPAR in diabetic group were significantly decreased than control group. LVGLS and LVGCS in pre-treatment diabetic group were significantly increased than post-treatment. LVGLS, LVGCS, LVTW and LVPAR had correlations among control, pre-treatment and post-treatment diabetic groups. There were no significant differences in LVEDV, LVESV, LVEF, LVT and R-R. LV systolic function of patients with T2DM complicated with microangiopathy was improved after treatment of continuous subcutaneous insulin infusion. In addition, therapeutic effect could be accurately evaluated by 3D-STE which had vital clinical application.

Complementary roles of m-mode echocardiography and scintigraphy in the evaluation of adults wih suspected left-to-right shunts

International Nuclear Information System (INIS)

Botvinick, E.H.; Schiller, N.B.

1980-01-01

We sought to determine the relative clinical abilities and roles of echocardiography and scintigraphy in left-to-right shunt diagnosis. M-mode echocardiographic and scintigraphic studies were analyzed in 37 adults presenting diagnostic difficulties with suspected left-to-right shunts. An enlarged right ventricle on M-mode echocardiography was a sensitive (100%) but not specific (55%) indicator of atrial septal defect (ASD). M-mode lacked sensitivity for ventricular eptal defect (VSD) and patent ductus arteriosus (PDA). In a few studies, two-dimensional echocardiography provided additional specific and clinically important anatomic information. Scintigraphic analysis demonstrated complete diagnostic accuracy and excellent localizing and quantitative abilities in all patients studied. Because it is extremely sensitie to ASD, free of any exposure to radioactivity, entirely noninvasive and may by simply and visually analyzed, echocardiography is the study of choice in the preliminary evaluation of patients presenting, diagnostic difficulty with suspected ASD. Scintigraphy is the study of choice in the preliminary evaluation of patients presenting diagnostic difficulty with suspected VSD and PDA and is the logical response to the finding of echocardiographic right ventricular enlargement when the diagnosis remains in doubt

What every radiologist should know about paediatric echocardiography

International Nuclear Information System (INIS)

Sorantin, Erich; Heinzl, Bernd

2014-01-01

Congenital heart defects (CHD) occur in less than one percent of all newborns. Echocardiography represents the imaging modality of choice for morphological and functional assessment. In childhood the different CHD types can be diagnosed trustfully and can be performed bedside. In the follow-up of CHD cross sectional imaging plays an important role and therefore it is essential for the radiologist to know the features, challenges and limitations of echocardiography. Within this review article a systematic approach for morphological and functional assessment of the heart will is given along with representative example images. In addition, typical echocardiographic findings in common CHD is presented. In older children, adolescents and grown-ups with CHD (GUCH) echocardiography suffers from limitations – partially due to skeletal deformations and lung emphysema. In particular right ventricular function assessment is not always possible by echocardiography. Therefore strengths and limitations of echocardiography will be discussed the role of cardiac magnetic resonance imaging (cMRI) and cardiac computed tomography (cCT) emphasized

What every radiologist should know about paediatric echocardiography

Energy Technology Data Exchange (ETDEWEB)

Sorantin, Erich, E-mail: erich.sorantin@medunigraz.at [Division of Pediatric Radiology, Department of Radiology, Medical University Graz, Auenbruggerplatz 34, A-8036 Graz (Austria); Heinzl, Bernd [Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Medical University Graz, Auenbruggerplatz 34, A-8036 Graz (Austria)

2014-09-15

Congenital heart defects (CHD) occur in less than one percent of all newborns. Echocardiography represents the imaging modality of choice for morphological and functional assessment. In childhood the different CHD types can be diagnosed trustfully and can be performed bedside. In the follow-up of CHD cross sectional imaging plays an important role and therefore it is essential for the radiologist to know the features, challenges and limitations of echocardiography. Within this review article a systematic approach for morphological and functional assessment of the heart will is given along with representative example images. In addition, typical echocardiographic findings in common CHD is presented. In older children, adolescents and grown-ups with CHD (GUCH) echocardiography suffers from limitations – partially due to skeletal deformations and lung emphysema. In particular right ventricular function assessment is not always possible by echocardiography. Therefore strengths and limitations of echocardiography will be discussed the role of cardiac magnetic resonance imaging (cMRI) and cardiac computed tomography (cCT) emphasized.

Registration-based Reconstruction of Four-dimensional Cone Beam Computed Tomography

DEFF Research Database (Denmark)

Christoffersen, Christian; Hansen, David Christoffer; Poulsen, Per Rugaard

2013-01-01

We present a new method for reconstruction of four-dimensional (4D) cone beam computed tomography from an undersampled set of X-ray projections. The novelty of the proposed method lies in utilizing optical flow based registration to facilitate that each temporal phase is reconstructed from the full...

Diagnostic value of echocardiography in infective endocarditis

International Nuclear Information System (INIS)

Luo Yinli; Ni Xianda; Hu Yuanping; Liu Jingyun; Yang Weiyu

2010-01-01

Objective: To investigate the feature and value of echocardiography for diagnosing infective endocarditis. Methods: The shape, size, echogenicity, distribution of vegetations and valvular injury of the heart were observed in 30 patients with infective endocarditis. Results: The vegetations were located in the aortic valves (10 cases), bicuspid valves (5), tricuspid valve (1), pulmonary valve (2), main pulmonary artery with patent ductus arteriosus (2), and right ventricle with ventricular septal defect (2). The size of vegetation ranged from 2 to 27 mm and the echogenicity of vegetations was low to high. The location, size, shape and amount of vegetations observed on echocardiography correlated well with the operative findings. Echocardiography also demonstrated underlying heart disease and abnormal hemodynamics induced by infective endocarditis. Conclusion: Echocardiography can determine the location, size, shape, amount of vegetation and concomitant cardiac disease in patients with infective endocarditis. It play an important role in treatment and prognosis. (authors)

Wall-motion tracking in fetal echocardiography-Influence of frame rate on longitudinal strain analysis assessed by two-dimensional speckle tracking.

Science.gov (United States)

Enzensberger, Christian; Achterberg, Friederike; Graupner, Oliver; Wolter, Aline; Herrmann, Johannes; Axt-Fliedner, Roland

2017-06-01

Frame rates (FR) used for strain analysis assessed by speckle tracking in fetal echocardiography show a considerable variation. The aim of this study was to investigate the influence of the FR on strain analysis in 2D speckle tracking. Fetal echocardiography was performed prospectively on a Toshiba Aplio 500 system and a Toshiba Artida system, respectively. Based on an apical or basal four-chamber view of the fetal heart, cine loops were stored with a FR of 30 fps (Aplio 500) and 60 fps (Artida/Aplio 500). For both groups (30fps and 60fps), global and segmental longitudinal peak systolic strain (LPSS) values of both, left (LV) and right ventricle (RV), were assessed by 2D wall-motion tracking. A total of 101 fetuses, distributed to three study groups, were included. The mean gestational age was 25.2±5.0 weeks. Mean global LPSS values for RV in the 30 fps group and in the 60 fps group were -16.07% and -16.47%, respectively. Mean global LPSS values for LV in the 30 fps group and in the 60 fps group were -17.54% and -17.06%, respectively. Comparing global and segmental LPSS values of both, the RV and LV, did not show any statistically significant differences within the two groups. Performance of myocardial 2D strain analysis by wall-motion tracking was feasible with 30 and 60 fps. Obtained global and segmental LPSS values of both ventricles were relatively independent from acquisition rate. © 2017, Wiley Periodicals, Inc.

Standardised imaging technique for guided M-mode and Doppler echocardiography in the horse.

Science.gov (United States)

Long, K J; Bonagura, J D; Darke, P G

1992-05-01

Eighteen echocardiographic images useful for diagnostic imaging, M-mode echocardiography, and Doppler echocardiography of the equine heart were standardised by relating the position of the axial beam to various intracardiac landmarks. The transducer orientation required for each image was recorded in 14 adult horses by describing the degree of sector rotation and the orientation of the axial beam relative to the thorax. Repeatable images could be obtained within narrow limits of angulation and rotation for 14 of the 18 standardised images evaluated. Twenty-seven National Hunt horses were subsequently examined using this standardised technique. Selected cardiac dimensions were measured from two-dimensional and guided M-mode studies. Satisfactory results were achieved in 26 of the 27 horses. There was no linear correlation between any of the measured cardiac values and bodyweight. There was no significant difference between measurements taken from the left and the right hemithorax. Six horses were imaged on three consecutive days to assess the repeatability of the measurements. No significant difference was found between measurements obtained on different days. This study demonstrates a method for standardised echocardiographic evaluation of the equine heart that is repeatable, valuable for teaching techniques of equine echocardiography, applicable for diagnostic imaging and quantification of cardiac size, and useful for the evaluation of blood-flow patterns by Doppler ultrasound.

MODERN POSSIBILITIES OF SPECKLE TRACKING ECHOCARDIOGRAPHY IN CLINICAL PRACTICE

Directory of Open Access Journals (Sweden)

V. S. Nikiforov

2017-01-01

Full Text Available Speckle-tracking echocardiography is promising modern technique for evaluation of structural and functional changes in the myocardium. It evaluates the indicator of global longitudinal myocardial deformation, which is more sensitive than ejection fraction to early changes of left ventricular contractility. The diagnostic capabilities of speckle tracking echocardiography are reflected in clinical recommendations and consensus statements of European Society of Cardiology (ESC, European Association of Cardiovascular Imaging (EACVI and American Society of Echocardiography (ASE. The aim of this paper is describe basic principles of speckle tracking echocardiography and clinical applications of this new technology. Attention is paid to the use of speckle tracking echocardiography in such heart pathologies as heart failure, coronary heart disease and myocardial infarction, left ventricular hypertrophy in arterial hypertension, hypertrophic cardiomyopathy and amyloidosis of the heart, valvular heart disease, constrictive pericarditis and cancer therapy-induced cardiotoxicity.

Four-dimensional computed tomographic analysis of esophageal mobility during normal respiration

NARCIS (Netherlands)

Dieleman, Edith M. T.; Senan, Suresh; Vincent, Andrew; Lagerwaard, Frank J.; Slotman, Ben J.; van Sörnsen de Koste, John R.

2007-01-01

BACKGROUND: Chemo-radiotherapy for thoracic tumors can result in high-grade radiation esophagitis. Treatment planning to reduce esophageal irradiation requires organ motion to be accounted for. In this study, esophageal mobility was assessed using four-dimensional computed tomography (4DCT). METHODS

The use of echocardiography in acute cardiovascular care

DEFF Research Database (Denmark)

Lancellotti, Patrizio; Price, Susanna; Edvardsen, Thor

2014-01-01

Echocardiography is one of the most powerful diagnostic and monitoring tools available to the modern emergency/critical care practitioner. Currently, there is a lack of specific European Association of Cardiovascular Imaging/Acute Cardiovascular Care Association recommendations for the use...... of echocardiography in acute cardiovascular care. In this document, we describe the practical applications of echocardiography in patients with acute cardiac conditions, in particular with acute chest pain, acute heart failure, suspected cardiac tamponade, complications of myocardial infarction, acute valvular heart...

The use of echocardiography in acute cardiovascular care

DEFF Research Database (Denmark)

Lancellotti, Patrizio; Price, Susanna; Edvardsen, Thor

2015-01-01

Echocardiography is one of the most powerful diagnostic and monitoring tools available to the modern emergency/ critical care practitioner. Currently, there is a lack of specific European Association of Cardiovascular Imaging/Acute Cardiovascular Care Association recommendations for the use...... of echocardiography in acute cardiovascular care. In this document, we describe the practical applications of echocardiography in patients with acute cardiac conditions, in particular with acute chest pain, acute heart failure, suspected cardiac tamponade, complications of myocardial infarction, acute valvular heart...

The use of echocardiography in acute cardiovascular care

DEFF Research Database (Denmark)

Lancellotti, Patrizio; Price, Susanna; Edvardsen, Thor

2015-01-01

Echocardiography is one of the most powerful diagnostic and monitoring tools available to the modern emergency/critical care practitioner. Currently, there is a lack of specific European Association of Cardiovascular Imaging/Acute Cardiovascular Care Association recommendations for the use...... of echocardiography in acute cardiovascular care. In this document, we describe the practical applications of echocardiography in patients with acute cardiac conditions, in particular with acute chest pain, acute heart failure, suspected cardiac tamponade, complications of myocardial infarction, acute valvular heart...

The influence of percutaneous closure of patent ductus arteriosus on left ventricular size and function: a prospective study using two- and three-dimensional echocardiography and measurements of serum natriuretic peptides.

Science.gov (United States)

Eerola, Anneli; Jokinen, Eero; Boldt, Talvikki; Pihkala, Jaana

2006-03-07

We aimed to evaluate the effect of percutaneous closure of patent ductus arteriosus (PDA) on left ventricular (LV) hemodynamics. Today, most PDAs are closed percutaneously. Little is known, however, about hemodynamic changes after the procedure. Of 37 children (ages 0.6 to 10.6 years) taken to the catheterization laboratory for percutaneous PDA closure, the PDA was closed in 33. Left ventricular diastolic and systolic dimensions, volumes, and function were examined by two-dimensional (2D) and three-dimensional (3D) echocardiography and serum concentrations of natriuretic peptides measured before PDA closure, on the following day, and 6 months thereafter. Control subjects comprised 36 healthy children of comparable ages. At baseline, LV diastolic diameter measured >+2 SD in 5 of 33 patients. In 3D echocardiography, a median LV diastolic volume measured 54.0 ml/m2 in the control subjects and 58.4 ml/m2 (p closure and 57.2 ml/m2 (p = NS) 6 months after closure. A median N-terminal brain natriuretic peptide (pro-BNP) concentration measured 72 ng/l in the control group and 141 ng/l in the PDA group before closure (p = 0.001) and 78.5 ng/l (p = NS) 6 months after closure. Patients differed from control subjects in indices of LV systolic and diastolic function at baseline. By the end of follow-up, all these differences had disappeared. Even in the subgroup of patients with normal-sized LV at baseline, the LV diastolic volume decreased significantly during follow-up. Changes in LV volume and function caused by PDA disappear by 6 months after percutaneous closure. Even the children with normal-sized LV benefit from the procedure.

Bosonisation of four dimensional real fermionic string models and asymmetric orbifolds

International Nuclear Information System (INIS)

Bailin, D.; Dunbar, D.C.; Love, A.

1990-01-01

Models of four dimensional strings based on internal world-sheet fermions are bosonised and the partition functions are compared with the partition functions of asymmetric Z 2 M orbifold models. Selection rules and couplings are also compared between the two formations. (orig.)

MRI and echocardiography in the diagnosis of cardiac amyloidosis

International Nuclear Information System (INIS)

Wang Jing; Kong Xiangquan; Zhou Guofeng; Xu Haibo; Chang Dandan; Feng Yiming; Liu Dingxi; Zhang Li; Xie Mingxing

2010-01-01

Objective: To assess the values of MRI and echocardiography for the diagnosis of cardiac amyloidosis (CA). Methods: Eleven cases with CA proved pathologically performed MRI and echocardiography, the findings were analyzed retrospectively. Results: The characteristic features of cardiac amyloidosis on MRI and echocardiography were: diffuse slight myocardial thickening of the left ventricular wall and interventricular septum (11 cases), slight myocardial thickening of the interatrial septum (5 cases), increased left ventricular mass (7 cases), enlarged left atrium (7 cases), impaired ventricular systolic and diastolic function (10 cases), pleural and pericardial effusions (11 and 9 cases). Echocardiography showed that myocardium was hyperechoic and presented as ground glass with some spotty hyperechoes in 6 cases. MRI revealed a distinct diffuse delayed enhancement of subendocardial and entire myocardium in 8 cases. Conclusion: Doppler echocardiography is the first-choice imaging technique and cardiac magnetic resonance imaging can provide more information for the diagnosis of CA. (authors)

Decision-making for supplying energy projects: A four-dimensional model

International Nuclear Information System (INIS)

Smith Stegen, Karen; Palovic, Martin

2014-01-01

Highlights: • Extant pipeline evaluation models offer insufficient supplier analysis tools. • We offer a four-dimensional decision-making tool to augment extant models. • Model employs four filters to help decision makers eliminate unsuitable suppliers. • Aids in prioritization of best courses of action for overcoming obstacles. • Case study of Nabucco pipeline shows Azerbaijan would have been best supply option. - Abstract: Importing states and regions employ myriad strategies to enhance energy security, from stockpiling to diversification to efficiency programs. As has occurred in recent years, importers can seek diversification by initiating pipeline and liquefied natural gas projects, meaning they may also have to select suppliers. However, most extant pipeline evaluation models erroneously assume suppliers are known and thus neglect supplier selection. We propose a decision-making tool to augment these older models: a systematic and replicable four-dimensional model to help policymakers and managers identify suitable suppliers and prioritize the best courses of action for overcoming obstacles. The first three dimensions—timeframe, supply availability and infrastructure constraints—filter out unsuitable suppliers. The fourth dimension then assesses the political, geopolitical and commercial stability of the remaining candidates. To demonstrate the model in practice, we assess the original Nabucco pipeline proposal, which was designed to transport gas from the Caspian and Middle East regions to Europe

The use of echocardiography in Wolff-Parkinson-White syndrome.

Science.gov (United States)

Cai, Qiangjun; Shuraih, Mossaab; Nagueh, Sherif F

2012-04-01

Endocardial mapping and radiofrequency catheter ablation are well established modalities for the diagnosis and treatment of patients with Wolff-Parkinson-White (WPW) syndrome associated with tachyarrhythmias. However, the electrophysiologic techniques are invasive, require radiation exposure, and lack spatial resolution of cardiac structures. A variety of echocardiographic techniques have been investigated as a non-invasive alternative for accessory pathway localization. Conventional M-mode echocardiography can detect the fine premature wall motion abnormalities associated with WPW syndrome. However, it is unable to identify the exact site of accessory pathway with sufficient accuracy. 2D, 2D-guided M-mode, and 2D phase analysis techniques are limited by image quality and endocardial border definition. Various modalities of tissue Doppler echocardiography significantly increase the accuracy of left-sided accessory pathway localization to 80-90% even in patients with poor acoustic window. However, right-sided pathways remain a diagnostic challenge. Strain echocardiography by speckle tracking has recently been evaluated and appears promising. Different cardiac abnormalities have been detected by echocardiography in WPW patients. Patients with WPW syndrome and tachyarrhythmias have impaired systolic and diastolic function which improves after radiofrequency ablation. Echocardiography is useful in identifying patient with accessory pathway-associated left ventricular dyssynchrony and dysfunction who may benefit from ablation therapy. Transesophageal and intracardiac echocardiography have been used to guide ablation procedure. Ablation-related complications detected by routine echocardiography are infrequent, rarely clinically relevant, and of limited value.

Quantification in echocardiography

NARCIS (Netherlands)

Korsten, H.H.M.; Mischi, M.; Grouls, R.J.E.; Jansen, A.H.M.; Dantzig, van J.M.; Peels, C.H.

2006-01-01

Until recently, more than 2200 Swan Ganz catheters were used annually in the operating rooms (OR) and intensive care unit (ICU) of the Catharina Hospital in Eindhoven, The Netherlands. After cardiologists who were specialists in echocardiography (ECHO) trained anesthesiologists in ECHO, the need for

Systematic review of cardiac output measurements by echocardiography vs. thermodilution

DEFF Research Database (Denmark)

Wetterslev, Mik; Møller-Sørensen, Hasse; Johansen, Rasmus Rothmann

2016-01-01

PURPOSE: Echocardiography is frequently used in the hemodynamic evaluation of critically ill patients, but inaccurate measurements may lead to wrong clinical decisions. The aim of our systematic review was to investigate the interchangeability of echocardiography with thermodilution technique...... of the studies assessed left-sided heart structures and the majority had small bias, wide limits of agreement, and high percentage error between echocardiography and thermodilution. In only two of the 24 studies the precision of each technique (echocardiography and thermodilution) was assessed before comparing...... them. In the single study evaluating trending ability using valid methodology, agreement was observed between echocardiography and thermodilution in detecting the directional changes in cardiac output, but the magnitude of changes varied considerably. CONCLUSIONS: The majority of studies comparing...

Annular dynamics of memo3D annuloplasty ring evaluated by 3D transesophageal echocardiography.

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Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Yoshioka, Daisuke; Sawa, Yoshiki

2018-04-01

We assessed the mitral annular motion after mitral valve repair with the Sorin Memo 3D® (Sorin Group Italia S.r.L., Saluggia, Italy), which is a unique complete semirigid annuloplasty ring intended to restore the systolic profile of the mitral annulus while adapting to the physiologic dynamism of the annulus, using transesophageal real-time three-dimensional echocardiography. 17 patients (12 male; mean age 60.4 ± 14.9 years) who underwent mitral annuloplasty using the Memo 3D ring were investigated. Mitral annular motion was assessed using QLAB®version8 allowing for a full evaluation of the mitral annulus dynamics. The mitral annular dimensions were measured throughout the cardiac cycle using 4D MV assessment2® while saddle shape was assessed through sequential measurements by RealView®. Saddle shape configuration of the mitral annulus and posterior and anterior leaflet motion could be observed during systole and diastole. The mitral annular area changed during the cardiac cycle by 5.7 ± 1.8%.The circumference length and diameter also changed throughout the cardiac cycle. The annular height was significantly higher in mid-systole than in mid-diastole (p 3D ring maintained a physiological saddle-shape configuration throughout the cardiac cycle. Real-time three-dimensional echocardiography analysis confirmed the motion and flexibility of the Memo 3D ring upon implantation.

Motion Mode and Two Dimensional Echocardiographic Measurements of Cardiac Dimensions of Indonesian Mongrel Dogs

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DENI NOVIANA

2011-03-01

Full Text Available Prevalence of heart disease in dogs was very high and required early diagnosis through physical examination, electrocardiogram, and echocardiography. Normal reference values of echocardiography are highly breedspecific and need for comparison and evaluation of dogs suspected with heart disease. Therefore the aim of this study was to establish normal reference echocardiographic values for Indonesian mongrel dogs, specifically to find out intracardiac dimensions, wall thickness, and fractional shortening. Motion-mode and two-dimensional echocardiography from right parasternal short axis and long axis view were performed on nine clinically healthy dogs consisting of five males and four males. The results showed that wall thickness and fractional shortening of Indonesia mongrel dogs were higher compared with those in the other breed that have the same average weight. As opposite, the intracardiac dimensions and lumen dimensions of aorta and left atrial diameter were smaller. These differences might occur due to factors other than the dog's habits and functions such as working and hunting, but can also be caused by the existence of breed differences. There was no significant difference between male and female dogs in terms of intracardiac dimension systole (P = 0.53, diastole (P = 0.38, fractional shortening (P = 0.053, and the ratio of aorta and left atrial diameter (P = 0.06.

Quantum theory of string in the four-dimensional space-time

International Nuclear Information System (INIS)

Pron'ko, G.P.

1986-01-01

The Lorentz invariant quantum theory of string is constructed in four-dimensional space-time. Unlike the traditional approach whose result was breaking of Lorentz invariance, our method is based on the usage of other variables for description of string configurations. The method of an auxiliary spectral problem for periodic potentials is the main tool in construction of these new variables

The scalar curvature problem on the four dimensional half sphere

CERN Document Server

Ben-Ayed, M; El-Mehdi, K

2003-01-01

In this paper, we consider the problem of prescribing the scalar curvature under minimal boundary conditions on the standard four dimensional half sphere. We provide an Euler-Hopf type criterion for a given function to be a scalar curvature for some metric conformal to the standard one. Our proof involves the study of critical points at infinity of the associated variational problem.

Comparision the value of detecting myocardial viability between low dose dobutamine stress MRI and echocardiography

International Nuclear Information System (INIS)

He Yi; Zhang Zhaoqi; Yu Wei; Miao Cuilian; Zhao Yike; Yan Zixu

2006-01-01

Objective: To Compare the diagnostic value between low dose dobutamine stress transthrotic echocardiography and low dose dobutamine stress MRI in detecting myocardial viability of chronic myocardial infarction. Methods: Rest and low dose dobutamine (5, 10 μg·kg -1 ·min -1 ) stress transthrotic echocardiography and cine-MRI were performed in 30 patients with chronic myocardial infarction. 24 patients underwent successful revascularization and 10 of them underwent another rest cine-MRI study to assess segmental myocardial functional recovery. Left ventricular were divided into 16 segments, the criteria of viability in different techniques is: MRI: dobutamine induced systolic wall thickening was ≥2 mm in akinetic or diskinetic segments at rest; Echocardiography: wall motion score reduced at least 1 after dobutamine stress in akinetic or' diskinetic segments at rest. Results: One hundren and eight segments showed wall motion abnormalities of 30 patients, 65 and 56 segments shows positive reaction, 43 and 52 segments shows negativereaction in MRI and echocardiography after dobutamine stress respectively. Kappa value of the two techniques is 0.75, concordance in both techniques is 88%. Twenty-four segments showed functional recovery, 14 segments remained dysfunction 3-6 months after revascularization, the sensitivity, specificity and accuracy of detecting myocardial viability in chronic myocardial infarction in MRI and echocardiography is 95.8% vs 79.2% (P>0.05), 85.7% vs 85.7% (P>0.05), 92.1% vs 81.6% (P>0.05) respectively. The sensitivity and accuracy of MRI is a little higher. Conclusion: The ability of detecting myocardial viability by both low dose dobutamine stress transthrotic echocardiography and low dose dobutamine stress MRI is similer, the sensitivity and accuracy of MRI is a little higher. (authors)

Four-dimensional optical multiband-OFDM for beyond 1.4 Tb/s serial optical transmission.

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Djordjevic, Ivan; Batshon, Hussam G; Xu, Lei; Wang, Ting

2011-01-17

We propose a four-dimensional (4D) coded multiband-OFDM scheme suitable for beyond 1.4 Tb/s serial optical transport. The proposed scheme organizes the N-dimensional (ND) signal constellation points in the form of signal matrix; employs 2D-inverse FFT and 2D-FFT to perform modulation and demodulation, respectively; and exploits both orthogonal polarizations. This scheme can fully exploit advantages of OFDM to deal with chromatic dispersion, PMD and PDL effects; and multidimensional signal constellations to improve OSNR sensitivity of conventional optical OFDM. The improvement of 4D-OFDM over corresponding polarization-multiplexed QAM (with the same number of constellation points) ranges from 1.79 dB for 16 signal constellation point-four-dimensional-OFDM (16-4D-OFDM) up to 4.53 dB for 128-4D-OFDM.

Pacing stress echocardiography

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Agrusta Marco

2005-12-01

Full Text Available Abstract Background High-rate pacing is a valid stress test to be used in conjunction with echocardiography; it is independent of physical exercise and does not require drug administration. There are two main applications of pacing stress in the echo lab: the noninvasive detection of coronary artery disease through induction of a regional transient dysfunction; and the assessment of contractile reserve through peak systolic pressure/ end-systolic volume relationship at increasing heart rates to assess global left ventricular contractility. Methods The pathophysiologic rationale of pacing stress for noninvasive detection of coronary artery disease is obvious, with the stress determined by a controlled increase in heart rate, which is a major determinant of myocardial oxygen demand, and thereby tachycardia may exceed a fixed coronary flow reserve in the presence of hemodynamically significant coronary artery disease. The use of pacing stress echo to assess left ventricular contractile reserve is less established, but promising. Positive inotropic interventions are mirrored by smaller end-systolic volumes and higher end-systolic pressures. An increased heart rate progressively increases the force of ventricular contraction (Bowditch treppe or staircase phenomenon. To build the force-frequency relationship, the force is determined at different heart rate steps as the ratio of the systolic pressure (cuff sphygmomanometer/end-systolic volume index (biplane Simpson rule. The heart rate is determined from ECG. Conclusion Two-dimensional echocardiography during pacing is a useful tool in the detection of coronary artery disease. Because of its safety and ease of repeatability noninvasive pacing stress echo can be the first-line stress test in patients with permanent pacemaker. The force-frequency can be defined as up- sloping (normal when the peak stress pacing systolic pressure/end-systolic volume index is higher than baseline and intermediate stress

Prenatal diagnosis of congenital heart disease using four-dimensional spatio-temporal image correlation (STIC) telemedicine via an Internet link: a pilot study.

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Viñals, F; Mandujano, L; Vargas, G; Giuliano, A

2005-01-01

To assess whether the spatio-temporal image correlation (STIC) acquisition technique can be taught to a general obstetrician by e-mail; whether STIC volume datasets can be transmitted over the Internet; and whether STIC volume datasets analyzed offline at a remote setting can be used to confirm or exclude major cardiac defects (TELE-STIC). This was a prospective study involving 50 pregnant women with gestational ages ranging between 20 and 36 weeks. These patients were selected by two general obstetricians (operators) working in geographically remote areas of Chile. Although both obstetricians were users of equipment capable of four-dimensional (4D) ultrasound with STIC, they lacked skill in the performance of fetal cardiac examination. A dedicated web disk was created to upload the acquired volume datasets using an Internet broadband connection. Offline analysis was performed by a single investigator experienced in fetal echocardiography (the administrator). A telemedicine link via the Internet was possible in all cases. Seventy-seven volume datasets were sent to the web server. A complete cardiac examination according to set criteria was achieved by the administrator in 86% of the cases scanned by one operator and 95% of the cases scanned by the other operator. Three patients had cardiac defects confirmed postnatally, two fetuses had extracardiac anomalies and one fetus had a suspected cardiac defect unconfirmed by second-opinion TELE-STIC. There were two isolated major congenital heart defects. Both patients were given advice by e-mail and teleconference using a web camera about the likely outcome and benefits of scheduling in utero transport to a tertiary care center. STIC volumes can be obtained by operators inexperienced in fetal echocardiography, transmitted via the Internet, and their analysis enables recognition of most of the structures and views necessary to assess fetal cardiac anatomy. The preliminary use of TELE-STIC allowed us to demonstrate that

Teaching focused echocardiography for rheumatic heart disease screening

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Daniel Engelman

2015-01-01

Full Text Available Screening for rheumatic heart disease (RHD requires workers skilled in echocardiography, which typically involves prolonged, specialized training. Task shifting echocardiographic screening to nonexpert health workers may be a solution in settings with limited human resources. An 8-week training program was designed to train health workers without any prior experience in focused echocardiography for RHD screening. Seven health workers participated. At the completion of training, the health workers performed unsupervised echocardiography on 16 volunteer children with known RHD status. A pediatric cardiologist assessed image quality. Participants provided qualitative feedback. The quality of echocardiograms were high at completion of training (55 of 56 were adequate for diagnosis and all cases of RHD were identified. Feedback was strongly positive. Training health workers to perform focused echocardiography for RHD screening is feasible. After systematic testing for accuracy, this training program could be adapted in other settings seeking to expand echocardiographic capabilities.

Teaching focused echocardiography for rheumatic heart disease screening

International Nuclear Information System (INIS)

Engelman, Daniel; Kado, Joseph H; Reményi, Bo; Colquhoun, Samantha M; Watson, Caroline; Rayasidamu, Sera C; Steer, Andrew C

2005-01-01

Screening for rheumatic heart disease (RHD) requires workers skilled in echocardiography, which typically involves prolonged, specialized training. Task shifting echocardiographic screening to nonexpert health workers may be a solution in settings with limited human resources. An 8-week training program was designed to train health workers without any prior experience in focused echocardiography for RHD screening. Seven health workers participated. At the completion of training, the health workers performed unsupervised echocardiography on 16 volunteer children with known RHD status. A pediatric cardiologist assessed image quality. Participants provided qualitative feedback. The quality of echocardiograms were high at completion of training (55 of 56 were adequate for diagnosis) and all cases of RHD were identified. Feedback was strongly positive. Training health workers to perform focused echocardiography for RHD screening is feasible. After systematic testing for accuracy, this training program could be adapted in other settings seeking to expand echocardiographic capabilities

Energy and angular-momentum non-conservation in four-dimensional gauge theories

International Nuclear Information System (INIS)

Manohar, A.

1985-01-01

We study energy and angular-momentum non-conservation on four-dimensional chiral gauge theories using Landau levels. These effects are physical manifestations of the usual gauge anomaly, and enable us to understand in a semi-classical approximation why anomaly cancellation is required for a consistent field theory. (orig.)

On the four-dimensional character of micro-physical phenomena

International Nuclear Information System (INIS)

Rietdijk, C.W.

1984-01-01

It is proved that retroactive effects exist in Nature. This emphasizes the fact that micro-processes constitute integrated wholes so much that it is no longer far-fetched to posit the hypothesis that events, that is, action, rather than objects, constitute the proper stuff of the (four-dimensional) Universe. Mind here, too, that retroactivity implies that the future and future parts of events 'exist already'. Then, distances between (e.g., alternative) events A and B have to be measured by the quantity of 'occurring' or action that is needed in order to transform event A into event B. The action metric so introduced appears to be in a position to solve the nonlocality paradoxes of quantum mechanics such as wave-particle 'duality' and the EPR paradox. In this connection, the Minkowski metric corresponds to a macro scheme which cannot be 'interpolated' to within a micro-process, i.e., to within action quanta, without producing serious metrical distortions. Generally, metric is considered to be a property of events, it having no existence independent of them as a 'pre-existing scheme'. Planck's elementary quantities of action h are seen as real entities in the four-dimensional world, i.e., as the 'atoms of occurring'. By intersecting (dilated) series of them with a now-hyperplane we in an imaginable way get the wave patterns satisfying the relevant wave equation. (Auth.)

Acquiring a four-dimensional computed tomography dataset using an external respiratory signal

International Nuclear Information System (INIS)

Vedam, S S; Keall, P J; Kini, V R; Mostafavi, H; Shukla, H P; Mohan, R

2003-01-01

Four-dimensional (4D) methods strive to achieve highly conformal radiotherapy, particularly for lung and breast tumours, in the presence of respiratory-induced motion of tumours and normal tissues. Four-dimensional radiotherapy accounts for respiratory motion during imaging, planning and radiation delivery, and requires a 4D CT image in which the internal anatomy motion as a function of the respiratory cycle can be quantified. The aims of our research were (a) to develop a method to acquire 4D CT images from a spiral CT scan using an external respiratory signal and (b) to examine the potential utility of 4D CT imaging. A commercially available respiratory motion monitoring system provided an 'external' tracking signal of the patient's breathing. Simultaneous recording of a TTL 'X-Ray ON' signal from the CT scanner indicated the start time of CT image acquisition, thus facilitating time stamping of all subsequent images. An over-sampled spiral CT scan was acquired using a pitch of 0.5 and scanner rotation time of 1.5 s. Each image from such a scan was sorted into an image bin that corresponded with the phase of the respiratory cycle in which the image was acquired. The complete set of such image bins accumulated over a respiratory cycle constitutes a 4D CT dataset. Four-dimensional CT datasets of a mechanical oscillator phantom and a patient undergoing lung radiotherapy were acquired. Motion artefacts were significantly reduced in the images in the 4D CT dataset compared to the three-dimensional (3D) images, for which respiratory motion was not accounted. Accounting for respiratory motion using 4D CT imaging is feasible and yields images with less distortion than 3D images. 4D images also contain respiratory motion information not available in a 3D CT image

Detection of congenital heart disease by fetal echocardiography

International Nuclear Information System (INIS)

Fayyaz, A.; Majeed, S.M.I.

2013-01-01

Objective: The objective of the study was to determine the sensitivity, specificity, accuracy and predictive value of fetal echocardiography in our set up using postnatal echocardiography as gold standard. Study Design: Validation study. Place and Duration of study: This is an ongoing study in the Radiology department of CMH Rawalpindi and Armed Forces Institute of Cardiology (AFIC) Rawalpindi and the data collected from January 2007 to Jan 2012 is presented. Patients and Methods: Two hundred eighty seven patients reported for fetal echocardiography. Two hundred twenty nine patients were subsequently included in the study. These included patients of all ages who reported to the Radiology department of CMH Rawalpindi for fetal echocardiography. Fetal echo was done on Toshiba Aplio with 3.5 MHz probe having Doppler facility. Post natal evaluation was done by a pediatric cardiologist. Results: There were 207 (90.4%) true negative cases, 15 (6.6%) true positive, 2 (0.9%) false positive and 6 (2.2%) false negative cases. The sensitivity, specificity, positive and negative predictive values were 75%, 99%, 88%, 97% respectively. Conclusion: Fetal echocardiography has high specificity, negative predictive values and accuracy and cases diagnosed as normal can reassure the parents about the normal cardiac status of the fetus. (author)

No-go theorems for R symmetries in four-dimensional GUTs

CERN Document Server

Fallbacher, Maximilian; Vaudrevange, Patrick K S

2011-01-01

We prove that it is impossible to construct a grand unified model, based on a simple gauge group, in four dimensions that leads to the exact MSSM, nor to a singlet extension, and possesses an unbroken R symmetry. This implies that no MSSM model with either a Z_{M>=3}^R or U(1)_R symmetry can be completed by a four-dimensional GUT in the ultraviolet. However, our no-go theorem does not apply to GUT models with extra dimensions. We also show that it is impossible to construct a 4D GUT that leads to the MSSM plus an additional anomaly-free symmetry that forbids the mu term.

Four dimensional sigma model coupled to the metric tensor field

International Nuclear Information System (INIS)

Ghika, G.; Visinescu, M.

1980-02-01

We discuss the four dimensional nonlinear sigma model with an internal O(n) invariance coupled to the metric tensor field satisfying Einstein equations. We derive a bound on the coupling constant between the sigma field and the metric tensor using the theory of harmonic maps. A special attention is paid to Einstein spaces and some new explicit solutions of the model are constructed. (author)

Three-dimensional echocardiographic assessment of the repaired mitral valve.

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Maslow, Andrew; Mahmood, Feroze; Poppas, Athena; Singh, Arun

2014-02-01

This study examined the geometric changes of the mitral valve (MV) after repair using conventional and three-dimensional echocardiography. Prospective evaluation of consecutive patients undergoing mitral valve repair. Tertiary care university hospital. Fifty consecutive patients scheduled for elective repair of the mitral valve for regurgitant disease. Intraoperative transesophageal echocardiography. Assessments of valve area (MVA) were performed using two-dimensional planimetry (2D-Plan), pressure half-time (PHT), and three-dimensional planimetry (3D-Plan). In addition, the direction of ventricular inflow was assessed from the three-dimensional imaging. Good correlations (r = 0.83) and agreement (-0.08 +/- 0.43 cm(2)) were seen between the MVA measured with 3D-Plan and PHT, and were better than either compared to 2D-Plan. MVAs were smaller after repair of functional disease repaired with an annuloplasty ring. After repair, ventricular inflow was directed toward the lateral ventricular wall. Subgroup analysis showed that the change in inflow angle was not different after repair of functional disease (168 to 171 degrees) as compared to those presenting with degenerative disease (168 to 148 degrees; p<0.0001). Three-dimensional imaging provides caregivers with a unique ability to assess changes in valve function after mitral valve repair. Copyright © 2014 Elsevier Inc. All rights reserved.

Haunted Kaluza universe with four-dimensional Lorentzian flat, Kerr, and Taub-NUT slices

International Nuclear Information System (INIS)

Ivanov, Rossen I.; Prodanov, Emil M.

2005-01-01

The duality between the original Kaluza's theory and Klein's subsequent modification is duality between slicing and threading decomposition of the five-dimensional spacetime. The field equations of the original Kaluza's theory lead to the interpretation of the four-dimensional Lorentzian Kerr and Taub-NUT solutions as resulting from static electric and magnetic charges and dipoles in the presence of ghost matter and constant dilaton, which models Newton's constant

Dobutamine stress echocardiography: a review and update

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Gilstrap LG

2014-04-01

Full Text Available Lauren Gray Gilstrap,1 R Sacha Bhatia,2 Rory B Weiner,3 David M Dudzinski3 1Division of Cardiology, Brigham and Women's Hospital, Boston, MA, USA; 2Institute for Health Systems Solutions, Women's College Hospital, Toronto, ON, Canada; 3Cardiology Division, Massachusetts General Hospital, Boston, MA, USA Abstract: Stress echocardiography is a noninvasive cardiovascular diagnostic test that provides functional and hemodynamic information in the assessment of a number of cardiac diseases. Performing stress echocardiography with a pharmacologic agent such as dobutamine allows for simulation of increased heart rate and increased myocardial physiologic demands in patients who may be unable to exercise due to musculoskeletal or pulmonary comorbidities. Dobutamine stress echocardiography (DSE, like exercise echocardiography, has found its primary application in ischemic heart disease, with roles in identification of obstructive epicardial coronary artery disease, detection of viable myocardium, and assessment of the efficacy of anti-ischemic medical therapy in patients with known coronary artery disease. DSE features prominently in the evaluation and management of valvular heart disease by helping to assess the effects of mitral and aortic stenoses, as well as a specific use in differentiating true severe valvular aortic stenosis from pseudostenosis that may occur in the setting of left ventricular systolic dysfunction. DSE is generally well tolerated, and its side effects and contraindications generally relate to consequences of excess inotropic and/or chronotropic stimulation of the heart. The aim of this paper is to review the indications, contraindications, advantages, disadvantages, and risks of DSE. Keywords: stress echocardiography, dobutamine, coronary artery disease, myocardial ischemia

Bifurcation structures and transient chaos in a four-dimensional Chua model

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Hoff, Anderson, E-mail: hoffande@gmail.com; Silva, Denilson T. da; Manchein, Cesar, E-mail: cesar.manchein@udesc.br; Albuquerque, Holokx A., E-mail: holokx.albuquerque@udesc.br

2014-01-10

A four-dimensional four-parameter Chua model with cubic nonlinearity is studied applying numerical continuation and numerical solutions methods. Regarding numerical solution methods, its dynamics is characterized on Lyapunov and isoperiodic diagrams and regarding numerical continuation method, the bifurcation curves are obtained. Combining both methods the bifurcation structures of the model were obtained with the possibility to describe the shrimp-shaped domains and their endoskeletons. We study the effect of a parameter that controls the dimension of the system leading the model to present transient chaos with its corresponding basin of attraction being riddled.

Noninvasive Localization of Accessory Pathways in Wolff-Parkinson-White Syndrome by Three-Dimensional Speckle Tracking Echocardiography.

Science.gov (United States)

Ishizu, Tomoko; Seo, Yoshihiro; Igarashi, Miyako; Sekiguchi, Yukio; Machino-Ohtsuka, Tomoko; Ogawa, Kojiro; Kuroki, Kenji; Yamamoto, Masahiro; Nogami, Akihiko; Kawakami, Yasushi; Aonuma, Kazutaka

2016-06-01

We have developed a noninvasive isochrone activation imaging (AI) system with 3-dimensional (3D) speckle tracking echocardiography (STE), which allows visualization of the wavefront image of mechanical propagation of the accessory pathway (ACP) in Wolff-Parkinson-White syndrome. Patients with manifest Wolff-Parkinson-White syndrome were imaged in 3D-STE AI mode, which quantified the time from QRS onset to regional endocardial deformation. In 2 patients with left- and right-side ACP, we confirmed that intraoperative contact endocardial electric mapping and the 3D-STE AI system showed comparable images pre- and postablation. In normal heart assessment by 3D-echo AI, the earliest activation sites were found at the attachment of the papillary muscles in the left ventricle and midseptum in the right ventricle, and none showed earliest activation at the peri-atrioventricular valve annuli. An analyzer who was unaware of the clinical information assessed 39 ACP locations in 38 Wolff-Parkinson-White syndrome patients using 3D-STE. All showed abnormal perimitral or tricuspid annular activations, and the location of 34 ACP (87%) showed agreement with the successful ablation sites within a 2-o'clock range. Especially for left free wall ACP, 17/18 (94%) showed consistency with the ablation site within a 2 o'clock range. Among 15 ACP at the ventricular septum, 9 (60%) showed early local activation in both right and left sides of the septum. Isochrone AI with 3D-STE may be a promising noninvasive imaging tool to assess cardiac synchronized activation in normal hearts and detect abnormal breakthrough of mechanical activation from both atrioventricular annuli in Wolff-Parkinson-White syndrome. © 2016 American Heart Association, Inc.

Gestational changes in left ventricular myocardial contractile function: new insights from two-dimensional speckle tracking echocardiography.

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Sengupta, Shantanu P; Bansal, Manish; Hofstra, Leonard; Sengupta, Partho P; Narula, Jagat

2017-01-01

The goal of this study was to evaluate the impact of pregnancy and labor on left ventricular (LV) myocardial mechanics using speckle tracking echocardiography (STE). Pregnancy is characterized by profound hormonal and hemodynamic alterations that directly or indirectly influence cardiac structure and function. However, the impact of these changes on left ventricular (LV) myocardial contractile function has not been fully elucidated. In this prospective, longitudinal study, 35 pregnant women underwent serial clinical and echocardiographic evaluation during each trimester and at labor. Two dimensional STE was performed to measure global LV longitudinal, circumferential and radial strain (GLS, GCS and GRS, respectively). Similar data obtained from 20 nulliparous, age-matched women were used as control. All strain values during pregnancy were adjusted for age and hemodynamic parameters. There was a progressive increase in heart rate, systolic and diastolic blood pressure, cardiac output and LV stroke-work during pregnancy. LV end-diastolic and end-systolic volumes also increased progressively but LV ejection fraction remained unaltered, except for slight reduction during the second trimester. Compared to the controls, GLS and GCS were reduced in the first trimester itself (GLS -22.39 ± 5.43 % vs. -18.66 ± 0.64 %, P 0.0002; GCS -20.84 ± 3.20 vs. -17.88 ± 0.09, P counterbalancing changes in the myocardial mechanics. LV longitudinal and circumferential strain are reduced whereas radial strain is increased. These counterbalancing changes serve to maintain overall LV ejection performance within a normal range and enable the maternal heart to meet the hemodynamic demands of pregnancy and labor.

Reliability of quantitative echocardiography in adult sheep and goats

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Hallowell Gayle D

2012-09-01

Full Text Available Abstract Background Echocardiography is a non-invasive method for assessment of the ovine and caprine heart. Complete reference ranges for cardiac dimensions and time indices for both species are not currently available and reliability of these measurements has not been evaluated. The objectives for this study are to report reliability, normal cardiac dimensions and time indices in a large group of adult sheep and goats. Fifty-one adult sheep and forty adult goats were recruited. Full echocardiographic examinations were performed in the standing unsedated animal. All animals underwent echocardiography four times in a 72-hour period. Echocardiography was performed three times by one author and once by another. Images were stored and measured offline. Technique and measurement repeatability and reproducibility and any differences due to animal or day were evaluated. Reference ranges (mean ± 2 standard deviations were calculated for both species. Results Majority of the images obtained were of good to excellent quality. Image acquisition was straightforward with 5.4% of animals demonstrating a small scanning window. Reliability was excellent for majority of dimensions and time indices. There was less variation in repeatability when compared with reproducibility and differences were greater for technique than for measurements. Dimensions that were less reliable included those for right ventricular diameter and left ventricular free wall. There were many differences in cardiac dimensions between sheep and goats. Conclusions This study has demonstrated that specific reference ranges are required for these two species. Repeatability and reproducibility were excellent for the majority of cardiac dimensions and time indices suggesting that this technique is reliable and valuable for examination of clinical cases over time and for longitudinal research studies.

String propagation in an exact four-dimensional black hole background

International Nuclear Information System (INIS)

Mahapatra, S.

1997-01-01

We study string propagation in an exact, stringy, four-dimensional dyonic black hole background. The exact solutions in terms of elliptic functions describing string configurations in the J=0 limit are obtained by solving the string equations of motion and constraints. By using the covariant formalism, we also investigate the propagation of physical perturbations along the string in the given curved background. copyright 1997 The American Physical Society

Gauge constructs and immersions of four-dimensional spacetimes in (4 + k)-dimensional flat spaces: algebraic evaluation of gravity fields

International Nuclear Information System (INIS)

Edelen, Dominic G B

2003-01-01

Local action of the fundamental group SO(a, 4 + k - a) is used to show that any solution of an algebraically closed differential system, that is generated from matrix Lie algebra valued 1-forms on a four-dimensional parameter space, will generate families of immersions of four-dimensional spacetimes R 4 in flat (4 + k)-dimensional spaces M 4+k with compatible signature. The algorithm is shown to work with local action of SO(a, 4 + k - a) replaced by local action of GL(4 + k). Immersions generated by local action of the Poincare group on the target spacetime are also obtained. Evaluations of the line elements, immersion loci and connection and curvature forms of these immersions are algebraic. Families of immersions that depend on one or more arbitrary functions are calculated for 1 ≤ k ≤ 4. Appropriate sections of graphs of the conformal factor for two and three interacting line singularities immersed in M 6 are given in appendix A. The local immersion theorem given in appendix B shows that all local solutions of the immersion problem are obtained by use of this method and an algebraic extension in exceptional cases

Head-to-head comparison of peak supine bicycle exercise echocardiography and treadmill exercise echocardiography at peak and at post-exercise for the detection of coronary artery disease.

Science.gov (United States)

Peteiro, Jesús; Bouzas-Mosquera, Alberto; Estevez, Rodrigo; Pazos, Pablo; Piñeiro, Miriam; Castro-Beiras, Alfonso

2012-03-01

Supine bicycle exercise (SBE) echocardiography and treadmill exercise (TME) echocardiography have been used for evaluation of coronary artery disease (CAD). Although peak imaging acquisition has been considered unfeasible with TME, higher sensitivity for the detection of CAD has been recently found with this method compared with post-TME echocardiography. However, peak TME echocardiography has not been previously compared with the more standardized peak SBE echocardiography. The aim of this study was to compare peak TME echocardiography, peak SBE echocardiography, and post-TME echocardiography for the detection of CAD. A series of 116 patients (mean age, 61 ± 10 years) referred for evaluation of CAD underwent SBE (starting at 25 W, with 25-W increments every 2-3 min) and TME with peak and postexercise imaging acquisition, in a random sequence. Digitized images at baseline, at peak TME, after TME, and at peak SBE were interpreted in a random and blinded fashion. All patients underwent coronary angiography. Maximal heart rate was higher during TME, whereas systolic blood pressure was higher during SBE, resulting in similar rate-pressure products. On quantitative angiography, 75 patients had coronary stenosis (≥50%). In these patients, wall motion score indexes at maximal exercise were higher at peak TME (median, 1.45; interquartile range [IQR], 1.13-1.75) than at peak SBE (median, 1.25; IQR, 1.0-1.56) or after TME (median, 1.13; IQR, 1.0-1.38) (P = .002 between peak TME and peak SBE imaging, P peak TME (median, 5; IQR, 2-12) compared with peak SBE (median, 3; IQR, 0-8) or after TME (median, 2; IQR, 0-4) (P peak TME and peak SBE imaging, P peak TME, peak SBE, and post-TME echocardiography for CAD was 84%, 75%, and 60% (P = .001 between post-TME and peak TME echocardiography, P = .055 between post-TME and peak SBE echocardiography), with specificity of 63%, 80%, and 78%, respectively (P = NS) and accuracy of 77%, 77%, and 66%, respectively (P = NS). Peak TME

Role of modern 3D echocardiography in valvular heart disease

Science.gov (United States)

2014-01-01

Three-dimensional (3D) echocardiography has been conceived as one of the most promising methods for the diagnosis of valvular heart disease, and recently has become an integral clinical tool thanks to the development of high quality real-time transesophageal echocardiography (TEE). In particular, for mitral valve diseases, this new approach has proven to be the most unique, powerful, and convincing method for understanding the complicated anatomy of the mitral valve and its dynamism. The method has been useful for surgical management, including robotic mitral valve repair. Moreover, this method has become indispensable for nonsurgical mitral procedures such as edge to edge mitral repair and transcatheter closure of paravaluvular leaks. In addition, color Doppler 3D echo has been valuable to identify the location of the regurgitant orifice and the severity of the mitral regurgitation. For aortic and tricuspid valve diseases, this method may not be quite as valuable as for the mitral valve. However, the necessity of 3D echo is recognized for certain situations even for these valves, such as for evaluating the aortic annulus for transcatheter aortic valve implantation. It is now clear that this method, especially with the continued development of real-time 3D TEE technology, will enhance the diagnosis and management of patients with these valvular heart diseases. PMID:25378966

Simulations of four-dimensional simplicial quantum gravity as dynamical triangulation

International Nuclear Information System (INIS)

Agishtein, M.E.; Migdal, A.A.

1992-01-01

In this paper, Four-Dimensional Simplicial Quantum Gravity is simulated using the dynamical triangulation approach. The authors studied simplicial manifolds of spherical topology and found the critical line for the cosmological constant as a function of the gravitational one, separating the phases of opened and closed Universe. When the bare cosmological constant approaches this line from above, the four-volume grows: the authors reached about 5 x 10 4 simplexes, which proved to be sufficient for the statistical limit of infinite volume. However, for the genuine continuum theory of gravity, the parameters of the lattice model should be further adjusted to reach the second order phase transition point, where the correlation length grows to infinity. The authors varied the gravitational constant, and they found the first order phase transition, similar to the one found in three-dimensional model, except in 4D the fluctuations are rather large at the transition point, so that this is close to the second order phase transition. The average curvature in cutoff units is large and positive in one phase (gravity), and small negative in another (antigravity). The authors studied the fractal geometry of both phases, using the heavy particle propagator to define the geodesic map, as well as with the old approach using the shortest lattice paths

A four-dimensional variational chemistry data assimilation scheme for Eulerian chemistry transport modeling

Science.gov (United States)

Eibern, Hendrik; Schmidt, Hauke

1999-08-01

The inverse problem of data assimilation of tropospheric trace gas observations into an Eulerian chemistry transport model has been solved by the four-dimensional variational technique including chemical reactions, transport, and diffusion. The University of Cologne European Air Pollution Dispersion Chemistry Transport Model 2 with the Regional Acid Deposition Model 2 gas phase mechanism is taken as the basis for developing a full four-dimensional variational data assimilation package, on the basis of the adjoint model version, which includes the adjoint operators of horizontal and vertical advection, implicit vertical diffusion, and the adjoint gas phase mechanism. To assess the potential and limitations of the technique without degrading the impact of nonperfect meteorological analyses and statistically not established error covariance estimates, artificial meteorological data and observations are used. The results are presented on the basis of a suite of experiments, where reduced records of artificial "observations" are provided to the assimilation procedure, while other "data" is retained for performance control of the analysis. The paper demonstrates that the four-dimensional variational technique is applicable for a comprehensive chemistry transport model in terms of computational and storage requirements on advanced parallel platforms. It is further shown that observed species can generally be analyzed, even if the "measurements" have unbiased random errors. More challenging experiments are presented, aiming to tax the skill of the method (1) by restricting available observations mostly to surface ozone observations for a limited assimilation interval of 6 hours and (2) by starting with poorly chosen first guess values. In this first such application to a three-dimensional chemistry transport model, success was also achieved in analyzing not only observed but also chemically closely related unobserved constituents.

Echocardiography in the flight program

Science.gov (United States)

Charles, John B.; Bungo, Michael W.; Mulvagh, Sharon L.

1991-01-01

Observations on American and Soviet astronauts have documented the association of changes in cardiovascular function during orthostasis with space flight. A basic understanding of the cardiovascular changes occurring in astronauts requires the determination of cardiac output and total peripheral vascular resistance as a minimum. In 1982, we selected ultrasound echocardiography as our means of acquiring this information. Ultrasound offers a quick, non-invasive and accurate means of determining stroke volume which, when combined with the blood pressure and heart rate measurements of the stand test, allows calculation of changes in peripheral vascular resistance, the body's major response to orthostatic stress. The history of echocardiography in the Space Shuttle Program is discussed and the results are briefly presented.

Four-dimensional (4D) tracking of high-temperature microparticles

International Nuclear Information System (INIS)

Wang, Zhehui; Liu, Q.; Waganaar, W.; Fontanese, J.; James, D.; Munsat, T.

2016-01-01

High-speed tracking of hot and molten microparticles in motion provides rich information about burning plasmas in magnetic fusion. An exploding-wire apparatus is used to produce moving high-temperature metallic microparticles and to develop four-dimensional (4D) or time-resolved 3D particle tracking techniques. The pinhole camera model and algorithms developed for computer vision are used for scene calibration and 4D reconstructions. 3D positions and velocities are then derived for different microparticles. Velocity resolution approaches 0.1 m/s by using the local constant velocity approximation.

Echocardiography in Infective Endocarditis: State of the Art.

Science.gov (United States)

Afonso, Luis; Kottam, Anupama; Reddy, Vivek; Penumetcha, Anirudh

2017-10-25

In this review, we examine the central role of echocardiography in the diagnosis, prognosis, and management of infective endocarditis (IE). 2D transthoracic echocardiography (TTE) and transesophageal echocardiography TEE have complementary roles and are unequivocally the mainstay of diagnostic imaging in IE. The advent of 3D and multiplanar imaging have greatly enhanced the ability of the imager to evaluate cardiac structure and function. Technologic advances in 3D imaging allow for the reconstruction of realistic anatomic images that in turn have positively impacted IE-related surgical planning and intervention. CT and metabolic imaging appear to be emerging as promising ancillary diagnostic tools that could be deployed in select scenarios to circumvent some of the limitations of echocardiography. Our review summarizes the indispensable and central role of various echocardiographic modalities in the management of infective endocarditis. The complementary role of 2D TTE and TEE are discussed and areas where 3D TEE offers incremental value highlighted. An algorithm summarizing a contemporary approach to the workup of endocarditis is provided and major societal guidelines for timing of surgery are reviewed.

OPPORTUNITIES OF TRANSVAGINAL ECHOCARDIOGRAPHY FOR EARLY PRENATAL DIAGNOSIS OF INBORN HEART DISEASES IN FETUS

Directory of Open Access Journals (Sweden)

E.A. Shevchenko

2008-01-01

Full Text Available According to the literature data, transvaginal echocardiography (Echocg is the method, used for the doppler diagnostics in early terms of pregnancy (if principles of safety are observed. This method allows detecting about 70–97% of all prognostic cally significant inborn heart diseases in fetus, beginning at 12 week of pregnancy. a scheme of research includes estimation of four chamber cut of fetus heart, and study of state of its main arteries. This is an expert investigation, because it needs special grounding of specialist, high resolution ultrasonic equipment, and considerable expense of time. Wile parameters are estimated, it is necessary to use normative rates of sizes of ventricles and main arteries of fetus, developed by Russian experts, taking into account individual variations.Key words: transvaginal echocardiography, diagnosis, inborn heart disease.

Four-dimensional dose evaluation using deformable image registration in radiotherapy for liver cancer

Energy Technology Data Exchange (ETDEWEB)

Hoon Jung, Sang; Min Yoon, Sang; Ho Park, Sung; Cho, Byungchul; Won Park, Jae; Jung, Jinhong; Park, Jin-hong; Hoon Kim, Jong; Do Ahn, Seung [Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736 (Korea, Republic of)

2013-01-15

Purpose: In order to evaluate the dosimetric impact of respiratory motion on the dose delivered to the target volume and critical organs during free-breathing radiotherapy, a four-dimensional dose was evaluated using deformable image registration (DIR). Methods: Four-dimensional computed tomography (4DCT) images were acquired for 11 patients who were treated for liver cancer. Internal target volume-based treatment planning and dose calculation (3D dose) were performed using the end-exhalation phase images. The four-dimensional dose (4D dose) was calculated based on DIR of all phase images from 4DCT to the planned image. Dosimetric parameters from the 4D dose, were calculated and compared with those from the 3D dose. Results: There was no significant change of the dosimetric parameters for gross tumor volume (p > 0.05). The increase D{sub mean} and generalized equivalent uniform dose (gEUD) for liver were by 3.1%{+-} 3.3% (p= 0.003) and 2.8%{+-} 3.3% (p= 0.008), respectively, and for duodenum, they were decreased by 15.7%{+-} 11.2% (p= 0.003) and 15.1%{+-} 11.0% (p= 0.003), respectively. The D{sub max} and gEUD for stomach was decreased by 5.3%{+-} 5.8% (p= 0.003) and 9.7%{+-} 8.7% (p= 0.003), respectively. The D{sub max} and gEUD for right kidney was decreased by 11.2%{+-} 16.2% (p= 0.003) and 14.9%{+-} 16.8% (p= 0.005), respectively. For left kidney, D{sub max} and gEUD were decreased by 11.4%{+-} 11.0% (p= 0.003) and 12.8%{+-} 12.1% (p= 0.005), respectively. The NTCP values for duodenum and stomach were decreased by 8.4%{+-} 5.8% (p= 0.003) and 17.2%{+-} 13.7% (p= 0.003), respectively. Conclusions: The four-dimensional dose with a more realistic dose calculation accounting for respiratory motion revealed no significant difference in target coverage and potentially significant change in the physical and biological dosimetric parameters in normal organs during free-breathing treatment.

Dobutamine Stress Echocardiography and Tissue Synchronization Imaging

Science.gov (United States)

Tas, Hakan; Gundogdu, Fuat; Gurlertop, Yekta; Karakelleoglu, Sule

2008-01-01

Dobutamine stress echocardiography has emerged as a reliable method for the diagnosis of coronary artery disease and the management of its treatment. Several studies have shown that that this technique works with 80–85% accuracy in comparison with other imaging methods. There are few studies aimed at developing the clinical utility of dobutamine stress echocardiography for the evaluation of normal and abnormal segments that result from dobutamine stress with Tissue Synchronization Imaging. PMID:25610034

Real-time three-dimensional color Doppler echocardiography for characterizing the spatial velocity distribution and quantifying the peak flow rate in the left ventricular outflow tract

Science.gov (United States)

Tsujino, H.; Jones, M.; Shiota, T.; Qin, J. X.; Greenberg, N. L.; Cardon, L. A.; Morehead, A. J.; Zetts, A. D.; Travaglini, A.; Bauer, F.;

Basic echocardiography for undergraduate students: a comparison of different peer-teaching approaches.

Science.gov (United States)

Gradl-Dietsch, G; Menon, A K; Gürsel, A; Götzenich, A; Hatam, N; Aljalloud, A; Schrading, S; Hölzl, F; Knobe, M

2018-02-01

The aim of this study was to assess the impact of different teaching interventions in a peer-teaching environment on basic echocardiography skills and to examine the influence of gender on learning outcomes. We randomly assigned 79 s year medical students (55 women, 24 men) to one of four groups: peer teaching (PT), peer teaching using Peyton's four-step approach (PPT), team based learning (TBL) and video-based learning (VBL). All groups received theoretical and practical hands-on training according to the different approaches. Using a pre-post-design we assessed differences in theoretical knowledge [multiple choice (MC) exam], practical skills (Objective Structured Practical Examination, OSPE) and evaluation results with respect to gender. There was a significant gain in theoretical knowledge for all students. There were no relevant differences between the four groups regarding the MC exam and OSPE results. The majority of students achieved good or very good results. Acceptance of the peer-teaching concept was moderate and all students preferred medical experts to peer tutors even though the overall rating of the instructors was fairly good. Students in the Video group would have preferred a different training method. There was no significant effect of gender on evaluation results. Using different peer-teaching concepts proved to be effective in teaching basic echocardiography. Gender does not seem to have an impact on effectiveness of the instructional approach. Qualitative analysis revealed limited acceptance of peer teaching and especially of video-based instruction.

Adding Four- Dimensional Data Assimilation (a.k.a. grid nudging) to MPAS

Science.gov (United States)

Adding four-dimensional data assimilation (a.k.a. grid nudging) to MPAS.The U.S. Environmental Protection Agency is investigating the use of MPAS as the meteorological driver for its next-generation air quality model. To function as such, MPAS needs to operate in a diagnostic mod...

Statistical Entropy of Nonextremal Four-Dimensional Black Holes and U-Duality

International Nuclear Information System (INIS)

Horowitz, G.T.; Lowe, D.A.; Maldacena, J.M.

1996-01-01

We identify the states in string theory which are responsible for the entropy of near-extremal rotating four-dimensional black holes in N=8 supergravity. For black holes far from extremality (with no rotation), the Bekenstein-Hawking entropy is exactly matched by a mysterious duality invariant extension of the formulas derived for near-extremal black holes states. copyright 1996 The American Physical Society

The Role of Focused Echocardiography in Pediatric Intensive Care: A Critical Appraisal

Science.gov (United States)

Gaspar, Heloisa Amaral; Morhy, Samira Saady

2015-01-01

Echocardiography is a key tool for hemodynamic assessment in Intensive Care Units (ICU). Focused echocardiography performed by nonspecialist physicians has a limited scope, and the most relevant parameters assessed by focused echocardiography in Pediatric ICU are left ventricular systolic function, fluid responsiveness, cardiac tamponade and pulmonary hypertension. Proper ability building of pediatric emergency care physicians and intensivists to perform focused echocardiography is feasible and provides improved care of severely ill children and thus should be encouraged. PMID:26605333

Sonocubic fine: new three-dimensional ultrasound software to the screening of congenital heart diseases

Directory of Open Access Journals (Sweden)

Edward Araujo Júnior

2014-09-01

Full Text Available Congenital heart disease is the most common fetal congenital malformations; however, the prenatal rate detection still is low. The two-dimensional echocardiography is the "gold standard" exam to screening and diagnosis of congenital heart disease during the prenatal; however, this exam is operator-depending and it is realized only in high risk pregnancies. Spatio-temporal image correlation is a three-dimensional ultrasound software that analyses the fetal heart and your connections in the multiplanar and rendering modes; however, spatio-temporal image correlation too is operator-depending and time-consuming. We presenting a new three-dimensional software named Sonocubic fine to the screening of congenital heart disease. This software applies intelligent navigation technology to spatio-temporal image correlation volume datasets to automatically generate nine fetal echocardiography standard views. Thus, this new software tends to be less operator-depending and time-consuming.

Assessment of left ventricular regional function in affected and carrier dogs with duchenne muscular dystrophy using speckle tracking echocardiography

Directory of Open Access Journals (Sweden)

Yugeta Naoko

2011-05-01

Full Text Available Abstract Background Two-dimensional speckle tracking echocardiography (STE is a relatively new method to detect regional myocardial dysfunction. To assess left ventricular (LV regional myocardial dysfunction using STE in Duchenne muscular dystrophy model dogs (CXMDJ without overt clinical signs of heart failure. Methods Six affected dogs, 8 carrier dogs with CXMDJ, and 8 control dogs were used. Conventional echocardiography, systolic and diastolic function by Doppler echocardiography, tissue Doppler imaging (TDI, and strain indices using STE, were assessed and compared among the 3 groups. Results Significant differences were seen in body weight, transmitral E wave and E' wave derived from TDI among the 3 groups. Although no significant difference was observed in any global strain indices, in segmental analysis, the peak radial strain rate during early diastole in posterior segment at chordae the tendineae level showed significant differences among the 3 groups. Conclusions The myocardial strain rate by STE served to detect the impaired cardiac diastolic function in CXMDJ without any obvious LV dilation or clinical signs. The radial strain rate may be a useful parameter to detect early myocardial impairment in CXMDJ.

Echocardiography in Ebstein's anomaly

NARCIS (Netherlands)

W.J. Gussenhoven (Wilhelmina Johanna)

1984-01-01

textabstractIn this thesis the value of echocardiography is evaluated for the diagnosis of Ebstein's anomaly of the tricuspid valve. This congenital heart defect, first described in 1866 by Wilhelm Ebstein, is characterized by an apical displacement of the septal and inferior tricuspid valve

Usefulness and limitations of transthoracic echocardiography in heart transplantation recipients

Directory of Open Access Journals (Sweden)

Galderisi Maurizio

2008-01-01

Full Text Available Abstract Transthoracic echocardiography is a primary non-invasive modality for investigation of heart transplant recipients. It is a versatile tool which provides comprehensive information about cardiac structure and function. Echocardiographic examinations can be easily performed at the bedside and serially repeated without any patient's discomfort. This review highlights the usefulness of Doppler echocardiography in the assessment of left ventricular and right ventricular systolic and diastolic function, of left ventricular mass, valvular heart disease, pulmonary arterial hypertension and pericardial effusion in heart transplant recipients. The main experiences performed by either standard Doppler echocardiography and new high-tech ultrasound technologies are summarised, pointing out advantages and limitations of the described techniques in diagnosing acute allograft rejection and cardiac graft vasculopathy. Despite the sustained efforts of echocardiographic technique in predicting the biopsy state, endocardial myocardial biopsies are still regarded as the gold standard for detection of acute allograft rejection. Conversely, stress echocardiography is able to identify accurately cardiac graft vasculopathy and has a recognised prognostic in this clinical setting. A normal stress-echo justifies postponement of invasive studies. Another use of transthoracic echocardiography is the monitorisation and the visualisation of the catheter during the performance of endomyocardial biopsy. Bedside stress echocardiography is even useful to select appropriately heart donors with brain death. The ultrasound monitoring is simple and effective for monitoring a safe performance of biopsy procedures.

Color M-mode and pulsed wave tissue Doppler echocardiography

DEFF Research Database (Denmark)

Møller, J E; Søndergaard, E; Poulsen, S H

2001-01-01

To assess the association between color M-mode flow propagation velocity and the early diastolic mitral annular velocity (E(m)) obtained with tissue Doppler echocardiography and to assess the prognostic implications of the indexes, echocardiography was performed on days 1 and 5, and 1 and 3 month...

Acquired pulmonary artery stenosis in four dogs.

Science.gov (United States)

Scansen, Brian A; Schober, Karsten E; Bonagura, John D; Smeak, Daniel D

2008-04-15

4 dogs with acquired pulmonary artery stenosis (PAS) were examined for various clinical signs. One was a mixed-breed dog with congenital valvular PAS that subsequently developed peripheral PAS, one was a Golden Retriever with pulmonary valve fibrosarcoma, one was a Pembroke Welsh Corgi in which the left pulmonary artery had inadvertently been ligated during surgery for correction of patent ductus arteriosus, and one was a Boston Terrier with a heart-base mass compressing the pulmonary arteries. All 4 dogs were evaluated with 2-dimensional and Doppler echocardiography to characterize the nature and severity of the stenoses; other diagnostic tests were also performed. The mixed-breed dog with valvular and peripheral PAS was euthanized, surgical resection of the pulmonic valve mass was performed in the Golden Retriever, corrective surgery was performed on the Pembroke Welsh Corgi with left pulmonary artery ligation, and the Boston Terrier with the heart-base mass was managed medically. Acquired PAS in dogs may manifest as a clinically silent heart murmur, syncope, or right-sided heart failure. The diagnosis is made on the basis of imaging findings, particularly results of 2-dimensional and Doppler echocardiography. Treatment may include surgical, interventional, or medical modalities and is targeted at resolving the inciting cause.

Four-dimensional Microscope-Integrated Optical Coherence Tomography to Visualize Suture Depth in Strabismus Surgery.

Science.gov (United States)

Pasricha, Neel D; Bhullar, Paramjit K; Shieh, Christine; Carrasco-Zevallos, Oscar M; Keller, Brenton; Izatt, Joseph A; Toth, Cynthia A; Freedman, Sharon F; Kuo, Anthony N

2017-02-14

The authors report the use of swept-source microscope-integrated optical coherence tomography (SS-MIOCT), capable of live four-dimensional (three-dimensional across time) intraoperative imaging, to directly visualize suture depth during lateral rectus resection. Key surgical steps visualized in this report included needle depth during partial and full-thickness muscle passes along with scleral passes. [J Pediatr Ophthalmol Strabismus. 2017;54:e1-e5.]. Copyright 2017, SLACK Incorporated.

Role of echocardiography in the evaluation of syncope: a prospective study

Science.gov (United States)

Sarasin, F P; Junod, A-F; Carballo, D; Slama, S; Unger, P-F; Louis-Simonet, M

2002-01-01

Objective: To study the role of echocardiography in the stepwise evaluation of syncope. Design: A prospective observational study with an 18 month follow up. Setting: University teaching hospital providing primary and tertiary care. Subjects: 650 consecutive patients with syncope and clinical suspicion of an obstructive valvar lesion, or with syncope not explained by history, physical examination, or a 12 lead ECG, who underwent bidimensional Doppler transthoracic echocardiography. Main outcome measures: The causes of syncope were assigned using published diagnostic criteria. Echocardiography was considered diagnostic when confirming a suspected diagnosis, or when revealing occult cardiac disease explaining the syncope. Results: A systolic murmur was identified in 61 of the 650 patients (9%). Severe aortic stenosis was suspected in 20 of these and was confirmed by echocardiography in eight. Follow up excluded further cases of aortic stenosis. In patients with unexplained syncope (n = 155), routine echocardiography showed no abnormalities that established the cause of the syncope. Echocardiography was normal or non-relevant in all patients with a negative cardiac history and a normal ECG (n = 67). In patients with a positive cardiac history or an abnormal ECG (n = 88), echocardiography showed systolic dysfunction (left ventricular ejection fraction ≤ 40%) in 24 (27%) and minor non-relevant findings in the remaining 64. Arrhythmias were diagnosed in 12 of the 24 patients with systolic dysfunction (50%), and in 12 of the 64 remaining patients (19%) (p < 0.01). Conclusions: Echocardiography was most useful for assessing the severity of the underlying cardiac disease and for risk stratification in patients with unexplained syncope but with a positive cardiac history or an abnormal ECG. PMID:12231593

On 'Common time' in the four-dimensional symmetry framework

International Nuclear Information System (INIS)

Gulati, Shobha

1980-01-01

Recently Hsu has advanced a 'Four-Dimensional Symmetry Theory' with a 'Common time' for all inertial frames. He believes that such a 'Common time' is physically possible. However, as a consequence of 'Common time', Hsu asserts that the speed of light in some inertial frames is not necessarily invariant and isotropic - a result, quite contrary to Einstein's Principle of the constancy of the velocity of light. In the present paper, taking Hsu's 'Common time' at its face value, the author has demonstrated that his formulation itself leads to physically absurd results. A 'Common time' for all inertial frames is just not possible. (author)

A case of complete double aortic arch visualized by transthoracic echocardiography.

Science.gov (United States)

Saito, Naka; Kato, Shingo; Saito, Noritaka; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Kosuge, Masami; Kimura, Kazuo

2017-08-01

A case of double aortic arch that was well visualized using transthoracic echocardiography is reported. A 38-year-old man underwent transthoracic echocardiography for the evaluation of dyspnea. A suprasternal view of transthoracic echocardiography showed the ascending aorta bifurcate to left and right aortic arches, with blood flow from the ascending aorta to bilateral aortic arches. The diagnosis of right side-dominant double aortic arch was made, and the patient's symptom was conceivably related to compression of the trachea due to a vascular ring. This report indicates the potential usefulness of transthoracic echocardiography for noninvasive detection of double aortic arch in adults. © 2017, Wiley Periodicals, Inc.

Two-dimensional echocardiographic and RI angiographic features of aneurysm of the ascending aorta in patients with annuloaortic ectasia

International Nuclear Information System (INIS)

Nakamura, Kenji; Suzuki, Shin; Satomi, Gengi

1981-01-01

The purpose of this study was to compare the diagnostic value of two-dimensional echocardiography with that of other methods in the detection and localization of aneurysm involving the ascending aorta in patients with annuloaortic ectasia. Two-dimensional echocardiography, RI angiography, CT scan and aortography were performed in 19 patients (12 patients with Marfan's syndrome, 4 with aortitis syndrome and 3 with postoperative perivalvular aneurysm). Eight of 12 patients with Marfan's syndrome had dissection in the ascending aorta which was confirmed at surgery or autopsy. The following observations were obtained. 1) Dissection of the ascending aorta was clearly demonstrated on the two-dimensional echocardiogram in 7 patients by recording the intinal tear and flap, and in these cases the short axis two-dimensional echocardiogram of the ascending aorta was more useful in identifying the site and extent of dissection. 2) In patients with postoperative perivalvular aneurysms, RI angiography proved to be a more useful and sensitive technique in differentiating a leakage into the aneurysm from clots in the aneurysm. 3) CT scanning proved to be an insensitive technique to detect dissection of the ascending aneurysm and to differentiate a leakage from clots in the perivalvular aneurysm. From these observations, we concluded that two-dimensional echocardiography and RI angiography proved to be sensitive techniques in detecting dissection of the ascending aneurysm and evaluating a postoperative aneurysm in patients with annuloaortic ectasia. (author)

Targeted neonatal echocardiography services: need for standardized training and quality assurance.

Science.gov (United States)

Finan, Emer; Sehgal, Arvind; Khuffash, Afif El; McNamara, Patrick J

2014-10-01

Targeted neonatal echocardiography refers to a focused assessment of myocardial performance and hemodynamics directed by a specific clinical question. It has become the standard of care in many parts of the world, but practice is variable, and there has been a lack of standardized training and evaluation to date. Targeted neonatal echocardiography was first introduced to Canada in 2006. The purpose of this study was to examine the characteristics of targeted neonatal echocardiography practice and training methods in Canadian neonatal intensive care units (NICUs). A total of 142 Canadian neonatologists were invited to participate in an online survey, which was conducted in September 2010. The survey consisted of questions related to the availability of targeted neonatal echocardiography, clinical indications, benefits and risks, and training methods. The overall survey response rate was 65%. Forty-eight respondents (34%) indicated that targeted neonatal echocardiography was available in their units, and the program was introduced within the preceding 1 to 5 years. In centers where it was unavailable, lack of on-site echocardiography expertise was cited as the major barrier to implementation. The most common indications for targeted neonatal echocardiography included evaluation of a hemodynamically significant ductus arteriosus, systemic or pulmonary blood flow, and response to cardiovascular treatments. Only 27% of respondents, working in centers where targeted neonatal echocardiography existed, actually performed the studies themselves; most individuals completed 11 to 20 studies per month. Almost half of the respondents said that training was available in their institutions, but methods of training and evaluation were inconsistent. Eighty-seven percent of respondents reported no formalized process for assessment of ongoing competency after the initial training period. Targeted neonatal echocardiography is becoming more widely available and is gaining acceptance in

Echocardiography in the adult's congenital cardiopaties

International Nuclear Information System (INIS)

Escobar Q, Carlos I; Jaramillo U, Mario; Tenorio, Luis F; Molina V, Claudia; Saldarriaga A, Marcela; Arango, Angela M

2003-01-01

The number of adults with congenital heart disease is steadily increasing in the course of time. We ignore the prevalence and the most frequent diagnoses in our environment. A descriptive prospective study is presented. Between November 1 1999 and July 31 2001, 8871 Tran-thoracic and Tran-esophageal echocardiographies were performed in the Clinica Cardiovascular Santa Maria's echocardiography service. We found 143 congenital cardiopathies (1.6%) in 74 men and 69 women with a mean age of 37.7 +/- 18.4 years. the most frequent diagnoses were bicuspid aortic valve, atrial septal defect, ventricular septal defect, patent ductus arteriosus and Ebstein's anomaly. these findings agree with world wide data

Monte Carlo Study of Four-Dimensional Self-avoiding Walks of up to One Billion Steps

Science.gov (United States)

Clisby, Nathan

2018-04-01

We study self-avoiding walks on the four-dimensional hypercubic lattice via Monte Carlo simulations of walks with up to one billion steps. We study the expected logarithmic corrections to scaling, and find convincing evidence in support the scaling form predicted by the renormalization group, with an estimate for the power of the logarithmic factor of 0.2516(14), which is consistent with the predicted value of 1/4. We also characterize the behaviour of the pivot algorithm for sampling four dimensional self-avoiding walks, and conjecture that the probability of a pivot move being successful for an N-step walk is O([ log N ]^{-1/4}).

N = 1 supersymmetric indices and the four-dimensional A-model

Science.gov (United States)

Closset, Cyril; Kim, Heeyeon; Willett, Brian

2017-08-01

We compute the supersymmetric partition function of N = 1 supersymmetric gauge theories with an R-symmetry on M_4\\cong M_{g,p}× {S}^1 , a principal elliptic fiber bundle of degree p over a genus- g Riemann surface, Σ g . Equivalently, we compute the generalized supersymmetric index I_{M}{_{g,p}, with the supersymmetric three-manifold M_{g,p} as the spatial slice. The ordinary N = 1 supersymmetric index on the round three-sphere is recovered as a special case. We approach this computation from the point of view of a topological A-model for the abelianized gauge fields on the base Σ g . This A-model — or A-twisted two-dimensional N = (2 , 2) gauge theory — encodes all the information about the generalized indices, which are viewed as expectations values of some canonically-defined surface defects wrapped on T 2 inside Σ g × T 2. Being defined by compactification on the torus, the A-model also enjoys natural modular properties, governed by the four-dimensional 't Hooft anomalies. As an application of our results, we provide new tests of Seiberg duality. We also present a new evaluation formula for the three-sphere index as a sum over two-dimensional vacua.

An accessible four-dimensional treatment of Maxwell's equations in terms of differential forms

Science.gov (United States)

Sá, Lucas

2017-03-01

Maxwell’s equations are derived in terms of differential forms in the four-dimensional Minkowski representation, starting from the three-dimensional vector calculus differential version of these equations. Introducing all the mathematical and physical concepts needed (including the tool of differential forms), using only knowledge of elementary vector calculus and the local vector version of Maxwell’s equations, the equations are reduced to a simple and elegant set of two equations for a unified quantity, the electromagnetic field. The treatment should be accessible for students taking a first course on electromagnetism.

Speckle tracking echocardiography in acute lupus myocarditis: comparison to conventional echocardiography

Directory of Open Access Journals (Sweden)

Riëtte Du Toit

2017-07-01

Full Text Available Aims: Lupus myocarditis occurs in 5–10% of patients with systemic lupus erythematosus (SLE. No single feature is diagnostic of lupus myocarditis. Speckle tracking echocardiography (STE can detect subclinical left ventricular dysfunction in SLE patients, with limited research on its utility in clinical lupus myocarditis. We report on STE in comparison to conventional echocardiography in patients with clinical lupus myocarditis. Methods and results: A retrospective study was done at a tertiary referral hospital in South Africa. SLE patients with lupus myocarditis were included and compared to healthy controls. Echocardiographic images were reanalyzed, including global longitudinal strain through STE. A poor echocardiographic outcome was defined as final left ventricular ejection fraction (LVEF <40%. 28 SLE patients fulfilled the criteria. Global longitudinal strain correlated with global (LVEF: r = −0.808; P = 0.001 and regional (wall motion score: r = 0.715; P < 0.001 function. In patients presenting with a LVEF ≥50%, global longitudinal strain (P = 0.023, wall motion score (P = 0.005 and diastolic function (P = 0.004 were significantly impaired vs controls. Following treatment, LVEF (35–47% (P = 0.023 and wall motion score (1.88–1.5 (P = 0.017 improved but not global longitudinal strain. Initial LVEF (34%; P = 0.046 and global longitudinal strain (−9.5%; P = 0.095 were lower in patients with a final LVEF <40%. Conclusions: This is the first known report on STE in a series of patients with clinical lupus myocarditis. Global longitudinal strain correlated with regional and global left ventricular function. Global longitudinal strain, wall motion score and diastolic parameters may be more sensitive markers of lupus myocarditis in patients presenting with a preserved LVEF ≥50%. A poor initial LVEF and global longitudinal strain were associated with a persistent LVEF <40%. Echocardiography is a non-invasive tool with diagnostic and

Analysis of chronic aortic regurgitation by 2D and 3D echocardiography and cardiac MRI

DEFF Research Database (Denmark)

Stoebe, Stephan; Metze, Michael; Jurisch, Daniel

2018-01-01

) were assessed retrospectively by 2D, 3D echocardiography and cMRI in 55 chronic AR patients. Semi-quantitative parameters were assessed by 2D echocardiography. RESULTS: 22 (40%) patients had mild, 25 (46%) moderate and 8 (14%) severe AR. The quantitative volumetric approach was feasible using 2D, 3D...... echocardiography and cMRI, whereas the feasibility of semi-quantitative parameters varied considerably. LV volume (LVEDV, LVESV, SVtot) analyses showed good correlations between the different imaging modalities, although significantly increased LV volumes were assessed by cMRI. RVol was significantly different...... between 2D/3D echocardiography and 2D echocardiography/cMRI but was not significantly different between 3D echocardiography/cMRI. RF was not statistically different between 2D echocardiography/cMRI and 3D echocardiography/cMRI showing poor correlations (r

Raman scattering in air: four-dimensional analysis

International Nuclear Information System (INIS)

Lin, Y.; Kessler, T.J.; Lawrence, G.N.

1994-01-01

Inertial confinement fusion requires propagation of high-intensity, pulse-shaped IR and UV laser beams through long air paths. Such beams are subject to energy losses and decreased beam quality as a result by stimulated rotational Raman scattering (SRRS). In this paper we describe how quantum fluctuations, stimulated Raman amplification, diffraction propagation, and optical aberrations interact during the propagation of short, high-power laser pulses using a four-dimensional (4-D) model of the optical beams and the medium. The 4-D model has been incorporated into a general optical-propagation computer program that allows the entire optical system to be modeled and that is implemented on high-end personal computers, workstations, and supercomputers. The numerical model is used to illustrate important phenomena in the evolution of the optical beams. In addition, the OMEGA Upgrade laser system is used as a design case to illustrate the various considerations for inertial confinement fusion laser design

Exercise stress echocardiography in patients with valvular heart disease.

Science.gov (United States)

Sharma, Vishal; Newby, David E; Stewart, Ralph A H; Lee, Mildred; Gabriel, Ruvin; Van Pelt, Niels; Kerr, Andrew J

2015-09-01

Stress echocardiography is recommended for the assessment of asymptomatic patients with severe valvular heart disease (VHD) when there is discrepancy between symptoms and resting markers of severity. The aim of this study is to determine the prognostic value of exercise stress echocardiography in patients with common valve lesions. One hundred and fifteen patients with VHD (aortic stenosis (n=28); aortic regurgitation (n=35); mitral regurgitation, (n=26); mitral stenosis (n=26)), and age- and sex-matched controls (n=39) with normal ejection fraction underwent exercise stress echocardiography. The primary endpoint was a composite of death or hospitalization for heart failure. Asymptomatic VHD patients had lower exercise capacity than controls and 37% of patients achieved 60 mmHg) was associated with an increased risk of death or hospital admission (14% vs 1%, P<0.0001). The assessment of contractile reserve did not offer additional predictive value. In conclusion, an abnormal stress echocardiogram is associated with death and hospitalization with heart failure at 2 years. Stress echocardiography should be considered as part of the routine follow-up of all asymptomatic patients with VHD.

Four-dimensional conversion for spiritual leadership development: A missiological approach for African churches

Directory of Open Access Journals (Sweden)

Kalemba Mwambazambi

2014-02-01

Full Text Available The process of a four-dimensional conversion and/or transformation strives in helping the leadership of an organisation, especially such as the church, with practical ways that may lead to the development of an effective leadership by observing the four important aspects of human spirituality as elaborated on in the article. The spiritual, intellectual, moral and socio-political dimensions of the transformation can be catered for so that the complete inner being of humans, as well as their social and political attitudes and behaviours, can equally be transformed to maximum spiritual, personal and socio-political profitability. Mutombo-Mukendi demonstrates that the need for a spiritual leadership that can contribute to an effective transformation of Africa is dire, both for the church and the larger community. The real challenge is how to develop such leadership. This article provides intentional and practical ways that may lead to the development of the needed leadership. Four-dimensional transformation of people can be planned and carried out both in the church arena and in the surrounding communities. Skills development and transfer can also take place when skilled people from the church work with unskilled people from the community.

Analysis of chronic aortic regurgitation by 2D and 3D echocardiography and cardiac MRI

Science.gov (United States)

Stoebe, Stephan; Metze, Michael; Jurisch, Daniel; Tayal, Bhupendar; Solty, Kilian; Laufs, Ulrich; Pfeiffer, Dietrich; Hagendorff, Andreas

2018-01-01

Purpose The study compares the feasibility of the quantitative volumetric and semi-quantitative approach for quantification of chronic aortic regurgitation (AR) using different imaging modalities. Methods Left ventricular (LV) volumes, regurgitant volumes (RVol) and regurgitant fractions (RF) were assessed retrospectively by 2D, 3D echocardiography and cMRI in 55 chronic AR patients. Semi-quantitative parameters were assessed by 2D echocardiography. Results 22 (40%) patients had mild, 25 (46%) moderate and 8 (14%) severe AR. The quantitative volumetric approach was feasible using 2D, 3D echocardiography and cMRI, whereas the feasibility of semi-quantitative parameters varied considerably. LV volume (LVEDV, LVESV, SVtot) analyses showed good correlations between the different imaging modalities, although significantly increased LV volumes were assessed by cMRI. RVol was significantly different between 2D/3D echocardiography and 2D echocardiography/cMRI but was not significantly different between 3D echocardiography/cMRI. RF was not statistically different between 2D echocardiography/cMRI and 3D echocardiography/cMRI showing poor correlations (r echocardiography and 2D echocardiography/cMRI and good agreement was observed between 3D echocardiography/cMRI. Conclusion Semi-quantitative parameters are difficult to determine by 2D echocardiography in clinical routine. The quantitative volumetric RF assessment seems to be feasible and can be discussed as an alternative approach in chronic AR. However, RVol and RF did not correlate well between the different imaging modalities. The best agreement for grading of AR severity by RF was observed between 3D echocardiography and cMRI. LV volumes can be verified by different approaches and different imaging modalities. PMID:29519957

Digital echocardiography and telemedicine applications in pediatric cardiology.

Science.gov (United States)

Sable, Craig

2002-01-01

Digital echocardiography offers several advantages over videotape, including easy review, comparison, storage, postprocessing, and sharing of studies, quantitative analysis, and superior resolution. Newer echocardiography systems can write digital data to computer hardware, whereas older systems require digitization of analog data. Clinical and digital data compression is required to reduce study size. Clinical compression has been validated in several adult studies and one pediatric study. JPEG and MPEG digital compression ratios of 26:1 and 200:1, respectively, approximate S-videotape quality. JPEG is the DICOM 3.0 standard and is ideal for short loops, serial comparisons, and quantitative analysis. MPEG (the motion picture standard) lends itself to digitization of video streams and may be more attractive to pediatric cardiologists. Options for data storage and transfer range from limited local review to multiple offline review stations linked by a wide-area network. Telemedicine expands the capabilities of digital echocardiography in a "store and forward" or "real-time" format. Real-time neonatal telecardiology is accurate, impacts patient care, is cost-effective, and does not increase utilization. Cost, increased reliance on sonographers' skills, lack of accepted standards, and legal, licensure, and billing issues are obstacles to widespread acceptance of digital echocardiography and telemedicine.

Evaluation of prosthetic heart valves by transesophageal echocardiography: problems, pitfalls, and timing of echocardiography

NARCIS (Netherlands)

van den Brink, Renee B. A.

2006-01-01

Transesophageal echocardiography (TEE) is especially suitable for examination of prosthetic valves because of the proximity of the esophagus to the heart and absence of interference with lungs and ribs. This article reviews normal and abnormal morphologic characteristics of prosthetic valves such as

Recommendations for fetal echocardiography in twin pregnancy in 2016

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Leszczyńska Katarzyna

2016-01-01

Full Text Available Progress in the fields of fetal cardiology and fetal surgery have been seen not only in singleton pregnancies but also in multiple pregnancies. Proper interpretation of prenatal echocardiography is critical to clinical decision making, family counseling and perinatal management for obstetricians, maternal fetal medicine specialists, neonatologists and pediatric cardiologists. Fetal echocardiography is one of the most challenging and time-consuming prenatal examinations to perform, especially in multiple gestations. Performing just the basic fetal exam in twin gestations may take an hour or more. Thus, it is not practical to perform this exam in all cases of multiple gestations. Therefore our review and recommendations are related to fetal echocardiography in twin gestation.

Cardiodiagnostic imaging. MRT, CT, echocardiography and other methods

International Nuclear Information System (INIS)

Erbel, R.; Kreitner, K.F.; Barkhausen, J.; Thelen, M.

2007-01-01

The book presents a differentiated approach to cardiac imaging. The focus is n cardio-MR/-CT and echocardiography. These are highly complex methods involving new equipment, new protocols and indications. The techniques are new and difficult to learn for everybody concerned. MR, CT and echocardiography must always be viewed in the context of other diagnostic methods. The interdisciplinary approach of the book addresses both radiologists and cardiologists and relies on the vast experience of the authors. The book offers more than 500 large high-quality reference images reflecting the latest state of the art. It has amethodological section in which the current methods are described (X-ray, echocardiography, nuclear medicine, angiography, CT, MRT etc.) along with their advantages and shortcomings, and a clinical section in which the main indications are described in the common standardized way (anatomy, clinical picture, interpretation, differential diagnosis). (orig.)

Speckle tracking echocardiography derived 2-dimensional myocardial strain predicts left ventricular function and mass regression in aortic stenosis patients undergoing aortic valve replacement.

Science.gov (United States)

Staron, Adam; Bansal, Manish; Kalakoti, Piyush; Nakabo, Ayumi; Gasior, Zbigniew; Pysz, Piotr; Wita, Krystian; Jasinski, Marek; Sengupta, Partho P

2013-04-01

Regression of left ventricular (LV) mass in severe aortic stenosis (AS) following aortic valve replacement (AVR) reduces the potential risk of sudden death and congestive heart failure associated with LV hypertrophy. We investigated whether abnormalities of resting LV deformation in severe AS can predict the lack of regression of LV mass following AVR. Two-dimensional speckle tracking echocardiography (STE) was performed in a total of 100 subjects including 60 consecutive patients with severe AS having normal LV ejection fraction (EF > 50 %) and 40 controls. STE was performed preoperatively and at 4 months following AVR, including longitudinal strain assessed from the apical 4-chamber and 2-chamber views and the circumferential and rotational mechanics measured from the apical short axis view. In comparison with controls, the patients with AS showed a significantly lower LV longitudinal (p regression (>10 %) following AVR. In conclusion, STE can quantify the burden of myocardial dysfunction in patients with severe AS despite the presence of normal LV ejection fraction. Furthermore, resting abnormalities in circumferential strain at LV apex is related with a hemodynamic milieu associated with the lack of LV mass regression during short-term follow up after AVR.

Contrast echocardiography: history, micro bubble characteristics and instrumental techniques

International Nuclear Information System (INIS)

Cubides, Carlos; Restrepo, Gustavo; Aristizabal, Dagnovar; Munera, Ana

2006-01-01

This article describes the history of contrast echocardiography, the physical characteristics of the contrast agent's micro bubbles, the main instrumental tools (mechanical index, focus and focusing, frame rate), and the echocardiography techniques (second harmonic imaging, fusion harmonic, power pulse inversion imaging, triggered imaging, intermittent harmonic power Doppler, color power angio and acoustic densitometry), actually available for clinical use

The four-dimensional mouse whole-body phantoms and its application in medical imaging research

International Nuclear Information System (INIS)

Li Chongguo; Wu Dake

2012-01-01

Medical imaging simulation is a powerful tool for characterizing,evaluating,and optimizing medical imaging devices and techniques. A vital aspect of simulation is to have a realistic phantom or model of the subject's anatomy. Four-dimensional mouse whole-body phantoms provide realistic models of the mouse anatomy and physiology for imaging studies. When combined with accurate models for the imaging process,are capable of providing a wealth of realistic imaging data from subjects with various anatomies and motions (cardiac and respiratory) in health and disease. With this ability, the four-dimensional mouse whole-body phantoms have enormous potential to study the effects of anatomical, physiological and physical factors on medical and small animal imaging and to research new instrumentation, image acquisition strategies, image processing, reconstruction methods, image visualization and interpretation techniques. (authors)

Four-loop divergences of the two-dimensional (1,1) supersymmetric non-linear sigma model with a Wess-Zumino-Witten term

International Nuclear Information System (INIS)

Deriglazov, A.A.; Ketov, S.V.

1991-01-01

The four-loop divergences of the (1,1) supersymmetric two-dimensional non-linear σ-model with a Wess-Zumino-Witten term are analyzed. All the four-loop 1/ε-divergences in the general case (and an overall coefficient at the total four-loop contribution to the β-function) are shown to be reducible to only structures proportional to ζ(3). We explicitly calculate non-derivative contributions to the four-loop β-function from logarithmically divergent graphs. As a by-product, we obtain the complete four-loop β-function for the supersymmetric Wess-Zumino-Witten model. We use the partial results for the general four-loop β-function to shed some light on the structure of the (α') 3 -corrections to the superstring effective-action with antisymmetric-tensor field coupling. An inconsistency of the supersymmetrical dimensional regularisation via dimensional reduction in the presence of torsion is discovered at four loops, unless the string interpretation for the σ-model is adopted. (orig.)

Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

Energy Technology Data Exchange (ETDEWEB)

Schillaci, O. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Moroni, C. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Scopinaro, F. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Tavolaro, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Danieli, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Bossini, A. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Cassone, R. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Colella, A.C. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy)

1997-07-01

The aim of this study was to evaluate the diagnostic capability of technetium-99m sestamibi tomography based on dipyridamole echocardiography testing in hypertensives with chest pain, and to compare the scintigraphic results with those of coronary angiography, exercise electrocardiography and dipyridamole echocardiography. Forty subjects with mild to moderate hypertension, chest pain and no previous myocardial infarction were submitted to {sup 99m}Tc-sestamibi tomography (at rest and after high-dose dipyridamole echocardiography) and to exercise electrocardiography testing. At coronary angiography 22 patients (group A) had significant epicardial coronary artery disease ({>=}70% stenosis of at least one major vessel) and 18 normal main coronary vessels (group B). Dipyridamole {sup 99m}Tc-sestamibi imaging was positive in 21/22 patients of group A and in 5/18 of group B. Dipyridamole echocardiography was positive in 18/22 patients of group A and in 5/18 of group B. Exercise electrocardiography was positive in 15/22 patients of group A and in 11/18 of group B. Four out of five subjects in group B with positive results in all the tests showed a slow run-off of angiographic contrast medium, probably due to small-vessel disease. Significant epicardial coronary artery disease in hypertensives with chest pain is unlikely when dipyridamole {sup 99m}Tc-sestamibi tomography is negative. When scintigraphy is positive, either epicardial coronary artery disease or a small-vessel disease condition is possible. The association of scintigraphy with dipyridamole echocardiography testing allows the assessment of contractile function and myocardial perfusion by a single pharmacological stress. (orig./AJ). With 3 figs., 2 tabs.

[Early detection of the cardiotoxicity induced by chemotherapy drug through two-dimensional speckle tracking echocardiography combined with high-sensitive cardiac troponin T].

Science.gov (United States)

Wang, W; Kang, Y; Shu, X H; Shen, X D; He, B

2017-11-23

Objective: To investigate the clinical value of two-dimensional speckle tracking echocardiography(2D-STE) combined with high-sensitive cardiac troponin T (hs-cTnT) in early detection of the cardiotoxicity induced by chemotherapy drug. Methods: Seventy-five non-Hodgkin's lymphoma patients who received the CHOP regimen were recruited in this study. Conventional echocardiography and 2D-STE were performed on these patients before chemotherapy, the second day after the third course of chemotherapy (during chemotherapy) and the second day after the last course of chemotherapy (after chemotherapy). The parameters included left ventricular ejection fraction (LVEF), global longitudinal strain (LS), global circumferential strain (CS) and global radial strain (RS). The serum hs-cTNT levels were tested simultaneously. Results: Three cycles of CHOP were completed in 30 patients and 6-8 cycles of CHOP were completed in 45 patients. The LVEF of 75 patients before, during and after chemotherapy was (63.8±2.6)%, (63.8±2.8)% and (64.0±3.3)%, respectively, without significant difference ( P =0.91). However, the LS of 75 patients before, during and after chemotherapy was (-18.5±1.7)%, (-16.5±1.9)% and (-16.0±1.6)%, respectively. The CS was (-20.9±2.9)%, (-19.3±3.5)% and (-19.2±3.2)%, respectively. The RS was (39.2±6.4)%, (35.3±5.2)% and (35.0±6.2)%, respectively. The hs-cTnT was (0.001 0±0.002 0)ng/ml, (0.006 3±0.008 9)ng/ml and (0.007 3±0.003 8)ng/ml, respectively. The LS, CS and RS were significantly decreased while hs-cTnT was significantly increased during chemotherapy when compared to those before chemotherapy (all of P chemotherapy were marginally different from those during chemotherapy (all of P >0.05). Moreover, T(LS-SD), T(CS-SD) and T(RS-SD) showed no significant difference before, during and after chemotherapy (all of P >0.05). The reduction of LS was positively associated with the enhancement of hs-cTnT after chemotherapy ( r =0.60, P effectively and

Four-dimensional Yang-Mills theory, gauge invariant mass and fluctuating three-branes

International Nuclear Information System (INIS)

Niemi, Antti J; Slizovskiy, Sergey

2010-01-01

We are interested in a gauge invariant coupling between four-dimensional Yang-Mills field and a three-brane that can fluctuate into higher dimensions. For this we interpret the Yang-Mills theory as a higher dimensional bulk gravity theory with dynamics that is governed by the Einstein action, and with a metric tensor constructed from the gauge field in a manner that displays the original gauge symmetry as an isometry. The brane moves in this higher dimensional spacetime under the influence of its bulk gravity, with dynamics determined by the Nambu action. This introduces the desired interaction between the brane and the gauge field in a way that preserves the original gauge invariance as an isometry of the induced metric. After a prudent change of variables the result can be interpreted as a gauge invariant and massive vector field that propagates in the original spacetime R 4 . The presence of the brane becomes entirely invisible, expect for the mass.

Resolution enhancement of scanning four-point-probe measurements on two-dimensional systems

DEFF Research Database (Denmark)

Hansen, Torben Mikael; Stokbro, Kurt; Hansen, Ole

2003-01-01

A method to improve the resolution of four-point-probe measurements of two-dimensional (2D) and quasi-2D systems is presented. By mapping the conductance on a dense grid around a target area and postprocessing the data, the resolution can be improved by a factor of approximately 50 to better than 1....../15 of the four-point-probe electrode spacing. The real conductance sheet is simulated by a grid of discrete resistances, which is optimized by means of a standard optimization algorithm, until the simulated voltage-to-current ratios converges with the measurement. The method has been tested against simulated...

Two-dimensional echocardiographic and RI angiographic features of aneurysm of the ascending aorta in patients with annuloaortic ectasia

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K.; Suzuki, S.; Satomi, G. (Tokyo Women' s Medical Coll. (Japan). Heart Inst. and Hospital)

1981-03-01

The purpose of this study was to compare the diagnostic value of two-dimensional echocardiography with that of other methods in the detection and localization of aneurysm involving the ascending aorta in patients with annuloaortic ectasia. Two-dimensional echocardiography, RI angiography, CT scan and aortography were performed in 19 patients (12 patients with Marfan's syndrome, 4 with aortitis syndrome and 3 with postoperative perivalvular aneurysm). Eight of 12 patients with Marfan's syndrome had dissection in the ascending aorta which was confirmed at surgery or autopsy. The following observations were obtained. 1) Dissection of the ascending aorta was clearly demonstrated on the two-dimensional echocardiogram in 7 patients by recording the intinal tear and flap, and in these cases the short axis two-dimensional echocardiogram of the ascending aorta was more useful in identifying the site and extent of dissection. 2) In patients with postoperative perivalvular aneurysms, RI angiography proved to be a more useful and sensitive technique in differentiating a leakage into the aneurysm from clots in the aneurysm. 3) CT scanning proved to be an insensitive technique to detect dissection of the ascending aneurysm and to differentiate a leakage from clots in the perivalvular aneurysm. From these observations, we concluded that two-dimensional echocardiography and RI angiography proved to be sensitive techniques in detecting dissection of the ascending aneurysm and evaluating a postoperative aneurysm in patients with annuloaortic ectasia.

Evaluation of congenital heart disease by three-dimensional MR imaging

International Nuclear Information System (INIS)

Vannier, M.W.; Gutierrez, F.R.; Canter, C.E.; Yoffie, R.L.; Hildebolt, C.F.

1988-01-01

In an evaluation of the detectability of intra-and extracardiac morphologic defects with electrocardiographically gated magnetic resonance (MR) imaging, 100 patients were studied, including ten without and 90 with abnormalities. The abnormalities included septal defects, tetrology of Fallot, pulmonary atresia, transposition of the great vessels, and others. The patients with abnormalities were studied angiographically and with echocardiographic analyses. Two radiologists with cardiac MR imaging experience evaluated the scans in a blinded fashion, and the results were analyzed by means of receiver operating characteristic analysis. The diagnostic value of routine two-dimensional cardiac MR imaging was compared with that of three-dimensional reconstruction imaging and with the results of cardiac catheterization and echocardiography. The reported sensitivity and specificity of echocardiography in the detection of congenital heart disease is comparable to that of MR imaging. The differences in diagnostic value between various modalities for the imaging of congenital heart disease may be determined from the results of the preliminary series

Echocardiography derived three-dimensional printing of normal and abnormal mitral annuli

Directory of Open Access Journals (Sweden)

Feroze Mahmood

2014-01-01

Full Text Available Aims and Objectives: The objective of this study was to assess the clinical feasibility of using echocardiographic data to generate three-dimensional models of normal and pathologic mitral valve annuli before and after repair procedures. Materials and Methods: High-resolution transesophageal echocardiographic data from five patients was analyzed to delineate and track the mitral annulus (MA using Tom Tec Image-Arena software. Coordinates representing the annulus were imported into Solidworks software for constructing solid models. These solid models were converted to stereolithographic (STL file format and three-dimensionally printed by a commercially available Maker Bot Replicator 2 three-dimensional printer. Total time from image acquisition to printing was approximately 30 min. Results: Models created were highly reflective of known geometry, shape and size of normal and pathologic mitral annuli. Post-repair models also closely resembled shapes of the rings they were implanted with. Compared to echocardiographic images of annuli seen on a computer screen, physical models were able to convey clinical information more comprehensively, making them helpful in appreciating pathology, as well as post-repair changes. Conclusions: Three-dimensional printing of the MA is possible and clinically feasible using routinely obtained echocardiographic images. Given the short turn-around time and the lack of need for additional imaging, a technique we describe here has the potential for rapid integration into clinical practice to assist with surgical education, planning and decision-making.

A systematic method for using 3D echocardiography to evaluate tricuspid valve insufficiency in hypoplastic left heart syndrome.

Science.gov (United States)

Mart, Christopher Robin; Eckhauser, Aaron Wesley; Murri, Michael; Su, Jason Thomas

2014-09-01

With surgical palliation of hypoplastic left heart syndrome (HLHS), the tricuspid valve (TV) becomes the systemic atrioventricular valve and moderate/severe TV insufficiency (TVI), an adverse risk factor for survival to Fontan, has been reported in up to 35% of patients prior to stage I palliation. Precise echocardiographic identification of the mechanism of TVI cannot be determined by two-dimensional echocardiography. Three-dimensional echocardiography (3DE) can provide significant insight into the mechanisms of TVI. It is the intent of this report to propose a systematic method on how to evaluate and display 3DE images of the TV in HLHS which has not been done previously. TV anatomy, function, and the known mechanisms of insufficiency are reviewed. We defined three regions of the TV (anterior, posterior, septal) that can help define valve "leaflets" that incorporates the many variations of TV anatomy. To determine how the surgeon views the TV, a picture of a pathologic specimen of the TV was placed on a computer screen and rotated until it was oriented as it appears during surgery, the "surgeons view." We have proposed a systematic method for evaluating and displaying the TV using 3DE which can provide significant insight into the mechanisms causing TVI in HLHS. This has the potential to improve both the surgical approach to repairing the valve and, ultimately, patient outcomes.

Detection of left ventricular thrombi by computerised tomography

International Nuclear Information System (INIS)

Nair, C.K.; Sketch, M.H.; Mahoney, P.D.; Lynch, J.D.; Mooss, A.N.; Kenney, N.P.

1981-01-01

Sixteen patients suspected of having left ventricular mural thrombi were studied. All had suffered transmural myocardial infarction. Fifteen patients had a ventricular aneurysm. One had had systemic emboli. The mean length of time between the myocardial infarction and the study was 14.8 months, with a range of one month to 79 months. All patients underwent computerised tomography of the heart, M-mode echocardiography (M-mode), and two-dimensional echocardiography (2-D). Eight patients underwent left ventricular cineangiography. Five patients had surgical confirmation. Computerised tomography, two-dimensional, and M-mode echocardiography predicted left ventricular mural thrombi in 10, eight, and one of the 16 patients, respectively. Left ventricular cineangiography predicted left ventricular mural thrombi in four out of eight patients. Computerised tomography and left ventricular cineangiography correctly predicted the presence or absence of left ventricular thrombi in all five patients who underwent operation. In the same group, however, two-dimensional and M-mode echocardiography failed to predict the presence of thrombi in one and three patients, respectively. Among the 11 patients without surgical confirmation, one, in whom no left ventricular thrombi were shown by M-mode and two-dimensional echocardiography, was found to have thrombi on computerised tomography. In another, two-dimensional echocardiography was positive but this finding was not confirmed either by computerised tomography or by left ventricular angiography. (author)

Simulation-based training in echocardiography.

Science.gov (United States)

Biswas, Monodeep; Patel, Rajendrakumar; German, Charles; Kharod, Anant; Mohamed, Ahmed; Dod, Harvinder S; Kapoor, Poonam Malhotra; Nanda, Navin C

2016-10-01

The knowledge gained from echocardiography is paramount for the clinician in diagnosing, interpreting, and treating various forms of disease. While cardiologists traditionally have undergone training in this imaging modality during their fellowship, many other specialties are beginning to show interest as well, including intensive care, anesthesia, and primary care trainees, in both transesophageal and transthoracic echocardiography. Advances in technology have led to the development of simulation programs accessible to trainees to help gain proficiency in the nuances of obtaining quality images, in a low stress, pressure free environment, often with a functioning ultrasound probe and mannequin that can mimic many of the pathologies seen in living patients. Although there are various training simulation programs each with their own benefits and drawbacks, it is clear that these programs are a powerful tool in educating the trainee and likely will lead to improved patient outcomes. © 2016, Wiley Periodicals, Inc.

Exercise echocardiography in asymptomatic survivors of childhood cancer treated with anthracyclines

DEFF Research Database (Denmark)

Sieswerda, Elske; Kremer, Leontien C M; Vidmar, Suzanna

2010-01-01

BACKGROUND: Exercise echocardiography reveals abnormalities in asymptomatic childhood cancer survivors who previously have been treated with anthracyclines. We determined the added value of monitoring childhood cancer survivors with exercise echocardiography compared to monitoring with resting ec...

Targeted neonatal echocardiography services: need for standardized training and quality assurance.

LENUS (Irish Health Repository)

Finan, Emer

2014-10-01

Targeted neonatal echocardiography refers to a focused assessment of myocardial performance and hemodynamics directed by a specific clinical question. It has become the standard of care in many parts of the world, but practice is variable, and there has been a lack of standardized training and evaluation to date. Targeted neonatal echocardiography was first introduced to Canada in 2006. The purpose of this study was to examine the characteristics of targeted neonatal echocardiography practice and training methods in Canadian neonatal intensive care units (NICUs).

Annular dynamics after mitral valve repair with different prosthetic rings: A real-time three-dimensional transesophageal echocardiography study.

Science.gov (United States)

Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Kawamura, Masashi; Yoshioka, Daisuke; Saito, Tetsuya; Ueno, Takayoshi; Kuratani, Toru; Sawa, Yoshiki

2016-09-01

We assessed the effects of different types of prosthetic rings on mitral annular dynamics using real-time three-dimensional echocardiography (RT3DE). RT3DE was performed in 44 patients, including patients undergoing mitral annuloplasty using the Cosgrove-Edwards flexible band (Group A, n = 10), the semi-rigid Sorin Memo 3D ring (Group B, n = 17), the semi-rigid Edwards Physio II ring (Group C, n = 7) and ten control subjects. Various annular diameters were measured throughout the cardiac cycle. We observed flexible anterior annulus motion in all of the groups except Group C. A flexible posterior annulus was only observed in Group B and the Control group. The mitral annular area changed during the cardiac cycle by 8.4 ± 3.2, 6.3 ± 2.0, 3.2 ± 1.3, and 11.6 ± 5.0 % in Group A, Group B, Group C, and the Control group, respectively. The dynamic diastolic to systolic change in mitral annular diameters was lost in Group C, while it was maintained in Group A, and to a good degree in Group B. In comparison to the Control group, the mitral annulus shape was more ellipsoid in Group B and Group C, and more circular in Group A. Although mitral regurgitation was well controlled by all of the types of rings that were utilized in the present study, we demonstrated that the annulus motion and annulus shape differed according to the type of prosthetic ring that was used, which might provide important information for the selection of an appropriate prosthetic ring.

Two-Dimensional Speckle Tracking Echocardiography Detects Subclinical Left Ventricular Systolic Dysfunction among Adult Survivors of Childhood, Adolescent, and Young Adult Cancer

Directory of Open Access Journals (Sweden)

Anthony F. Yu

2016-01-01

Full Text Available Two-dimensional speckle tracking echocardiography (2DSTE provides a sensitive measure of left ventricular (LV systolic function and may aid in the diagnosis of cardiotoxicity. 2DSTE was performed in a cross-sectional study of 134 patients (mean age: 31.4±8.8 years; 55% male; mean time since diagnosis: 15.4±9.4 years previously treated with anthracyclines (mean cumulative dose: 320±124 mg/m2, with (n=52 or without (n=82 mediastinal radiotherapy. The prevalence of LV systolic dysfunction, defined as fractional shortening < 27%, LV ejection fraction (LVEF < 55%, and global longitudinal strain (GLS ≤ 16%, was 5.2%, 6.0%, and 23.1%, respectively. Abnormal GLS was observed in 24 (18% patients despite a normal LVEF. Indices of LV systolic function were similar regardless of anthracycline dose. However, GLS was worse (18.0 versus 19.0, p=0.003 and prevalence of abnormal GLS was higher (36.5% versus 14.6%, p=0.004 in patients treated with mediastinal radiotherapy. Mediastinal radiotherapy was associated with reduced GLS (p=0.040 after adjusting for sex, age, and cumulative anthracycline dose. In adult survivors of childhood, adolescent, and young adult cancer, 2DSTE frequently detects LV systolic dysfunction despite a normal LVEF and may be useful for the long-term cardiac surveillance of adult cancer survivors.

The use of TEE simulation in teaching basic echocardiography skills to senior anesthesiology residents.

Science.gov (United States)

Jelacic, Srdjan; Bowdle, Andrew; Togashi, Kei; VonHomeyer, Peter

2013-08-01

The authors evaluated the educational benefits of using a first-generation HeartWorks simulator to teach senior anesthesiology residents basic echocardiography skills. Prospective observational study. A single academic medical center (teaching hospital). Thirty-seven senior (fourth-year) anesthesiology residents participated in this study. Groups of 3 senior anesthesiology residents participated in a single 3-hour tutorial in the simulation laboratory in the authors' institution during their cardiothoracic anesthesiology rotation. A cardiothoracic anesthesiology faculty member demonstrated the use of the transesophageal echocardiography (TEE) simulator and instructed the residents on obtaining standard TEE views of normal anatomy. Prior to the laboratory session, the residents took an online multiple-choice pretest with 25 questions related to safety, probe manipulation, clinical application, and pathology, which was accompanied by echo images of normal cardiac anatomy and video clips of pathology. Three to four weeks after the TEE tutorial, the residents completed an online post-test and evaluation of the teaching session. There was a statistically significant increase in knowledge of normal echocardiographic anatomy (p = 0.04), with an average improvement in normal echocardiographic anatomy scores of 15%. Virtual reality TEE simulation technology was endorsed strongly by residents, produced a statistically significant improvement in knowledge of normal echocardiographic anatomy, and could be effective for teaching basic echocardiography to anesthesiology residents. Copyright © 2013 Elsevier Inc. All rights reserved.

Dynamic Three-Dimensional Geometry of the Aortic Valve Apparatus-A Feasibility Study

NARCIS (Netherlands)

Khamooshian, Arash; Amador, Yannis; Hai, Ting; Jeganathan, Jelliffe; Saraf, Maria; Mahmood, Eitezaz; Matyal, Robina; Khabbaz, Kamal R.; Mariani, Massimo; Mahmood, Feroze

OBJECTIVE: To provide (1) an overview of the aortic valve (AV) apparatus anatomy and nomenclature, and (2) data regarding the normal AV apparatus geometry and dynamism during the cardiac cycle obtained from three-dimensional transesophageal echocardiography (3D TEE). DESIGN: Retrospective

The diagnostic ability of echocardiography for infective endocarditis and its associated complications.

Science.gov (United States)

Vilacosta, Isidre; Olmos, Carmen; de Agustín, Alberto; López, Javier; Islas, Fabián; Sarriá, Cristina; Ferrera, Carlos; Ortiz-Bautista, Carlos; Sánchez-Enrique, Cristina; Vivas, David; San Román, Alberto

2015-11-01

Echocardiography, transthoracic and transoesophageal, plays a key role in the diagnosis and prognosis assessment of patients with infective endocarditis. It constitutes a major Duke criterion and is pivotal in treatment guiding. Seven echocardiographic findings are major criteria in the diagnosis of infective endocarditis (IE) (vegetation, abscess, pseudoaneurysm, fistulae, new dehiscence of a prosthetic valve, perforation and valve aneurysm). Echocardiography must be performed as soon as endocarditis is suspected. Transoesophageal echocardiography should be done in most cases of left-sided endocarditis to better define the anatomic lesions and to rule out local complications. Transoesophageal echocardiography is not necessary in isolated right-sided native valve IE with good quality transthoracic examination and unequivocal echocardiographic findings. Echocardiography is a very useful tool to assess the prognosis of patients with IE at any time during the course of the disease. Echocardiographic predictors of poor outcome include presence of periannular complications, prosthetic dysfunction, low left ventricular ejection fraction, pulmonary hypertension and very large vegetations.

Four-Dimensional Data Assimilation Using the Adjoint Method

Science.gov (United States)

Bao, Jian-Wen

The calculus of variations is used to confirm that variational four-dimensional data assimilation (FDDA) using the adjoint method can be implemented when the numerical model equations have a finite number of first-order discontinuous points. These points represent the on/off switches associated with physical processes, for which the Jacobian matrix of the model equation does not exist. Numerical evidence suggests that, in some situations when the adjoint method is used for FDDA, the temperature field retrieved using horizontal wind data is numerically not unique. A physical interpretation of this type of non-uniqueness of the retrieval is proposed in terms of energetics. The adjoint equations of a numerical model can also be used for model-parameter estimation. A general computational procedure is developed to determine the size and distribution of any internal model parameter. The procedure is then applied to a one-dimensional shallow -fluid model in the context of analysis-nudging FDDA: the weighting coefficients used by the Newtonian nudging technique are determined. The sensitivity of these nudging coefficients to the optimal objectives and constraints is investigated. Experiments of FDDA using the adjoint method are conducted using the dry version of the hydrostatic Penn State/NCAR mesoscale model (MM4) and its adjoint. The minimization procedure converges and the initialization experiment is successful. Temperature-retrieval experiments involving an assimilation of the horizontal wind are also carried out using the adjoint of MM4.

DOBUTAMINE STRESS-ECHOCARDIOGRAPHY: POSSIBILITY OF CLINICAL USAGE IN CARDIOLOGY PRACTICE

Directory of Open Access Journals (Sweden)

M. A. Saidova

2016-01-01

Full Text Available Currently stress-echocardiography or so-called burden echocardiography is essential method of patient examination to reveal latent ischemic heart disease (IHD. That is one of the mostly informative non-invasive methods of IHD diagnosis as well as efficacy evaluation of coronary angioplasty, surgical and pharmacological treatments of IHD. Dobutamine usage as a stress-agent at burden echocardiography allows evaluating not only ischemia but a myocardial vitality in post infarction area as well as clarify severity of valve stenosis, pulmonary hypertension and extent of latent obstruction of exhaust duct of the left ventricle. Method possibilities are presented as well as test protocol, main indications and contraindications.

Four-dimensional parameter estimation of plane waves using swarming intelligence

International Nuclear Information System (INIS)

Zaman Fawad; Munir Fahad; Khan Zafar Ullah; Qureshi Ijaz Mansoor

2014-01-01

This paper proposes an efficient approach for four-dimensional (4D) parameter estimation of plane waves impinging on a 2-L shape array. The 4D parameters include amplitude, frequency and the two-dimensional (2D) direction of arrival, namely, azimuth and elevation angles. The proposed approach is based on memetic computation, in which the global optimizer, particle swarm optimization is hybridized with a rapid local search technique, pattern search. For this purpose, a new multi-objective fitness function is used. This fitness function is the combination of mean square error and the correlation between the normalized desired and estimated vectors. The proposed hybrid scheme is not only compared with individual performances of particle swarm optimization and pattern search, but also with the performance of the hybrid genetic algorithm and that of the traditional approach. A large number of Monte—Carlo simulations are carried out to validate the performance of the proposed scheme. It gives promising results in terms of estimation accuracy, convergence rate, proximity effect and robustness against noise. (interdisciplinary physics and related areas of science and technology)

Functional Tricuspid Regurgitation Caused by Chronic Atrial Fibrillation: A Real-Time 3-Dimensional Transesophageal Echocardiography Study.

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Utsunomiya, Hiroto; Itabashi, Yuji; Mihara, Hirotsugu; Berdejo, Javier; Kobayashi, Sayuki; Siegel, Robert J; Shiota, Takahiro

2017-01-01

Functional tricuspid regurgitation (TR) with a structurally normal tricuspid valve (TV) may occur secondary to chronic atrial fibrillation (AF). However, the clinical and echocardiographic differences according to functional TR subtypes are unclear. Therefore, characterization of functional TR because of chronic AF (AF-TR) remains undetermined. To investigate the prevalence of AF-TR, 437 patients with moderate to severe TR underwent 3-dimensional (3D) transesophageal echocardiography. TR severity was determined by the averaged vena contracta width on apical and parasternal inflow views. The prevalence of AF-TR was 9.2%, whereas that of functional TR because of left-sided heart disease was 45.3%. Clinical features of AF-TR included advanced age, female sex, greater right atrial than left atrial enlargement and lower systolic pulmonary artery pressure compared with left-sided heart disease-TR with sinus rhythm (all P<0.05). In 3D TV assessment, patients with AF-TR had a larger TV annular area with weaker annular contraction (both P<0.001) but a smaller tethering angle (P<0.001) despite a similar leaflet coaptation status compared with patients with left-sided heart disease-TR with sinus rhythm. On multivariable analysis, only the TV annular area in midsystole (coefficient, 0.059; 95% confidence interval, 0.041-0.078 per 100 mm 2 ; P<0.001) was associated with TR severity in AF-TR. The annular area was more closely correlated with the right atrial volume than right ventricular end-systolic volume in AF-TR (P<0.001). AF-TR is not rare and is associated with advanced age and right atrial enlargement. TV deformations and their association with right heart remodeling differ between AF-TR and left-sided heart disease-TR. Our results suggest that in patients with TR secondary to AF, TV annuloplasty should be effective because this entity has annular dilatation without leaflet deformation. © 2017 American Heart Association, Inc.

Assessment of mitral apparatus in patients with acute inferoposterior myocardial infarction and ischaemic mitral regurgitation with two-dimensional echocardiography from anatomically correct imaging planes.

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Mėlinytė, Karolina; Valuckiene, Živile; Jurkevičius, Renaldas

2017-01-01

Ischaemic mitral regurgitation (IMR) is associated with adverse prognosis after myocardial infarction (MI) as a result of left ventricular remodelling and geometric deformation of the mitral apparatus (MA). The aim of this study was to assess MA from anatomically correct imaging planes in acute inferoposterior MI and IMR. Ninety-three patients with no structural cardiac valve abnormalities and the first acute inferoposterior MI were prospectively enrolled into the study. Two-dimensional transthoracic echocardiography for MA assessment was performed within 48 h of presentation after reperfusion therapy. Based on the degree of mitral regurgitation (MR), patients were divided into either a no significant MR (NMR) group (n = 52 with no or mild, grade 0-I MR) or an IMR group (n = 41 with grade ≥ 2 MR). The control group consisted of 45 healthy individuals. Ischaemic MR was related with dilatation of the left ventricle chambers, decrease in ejection fraction, increase in mitral annulus diameter and area, and changes in subvalvular apparatus when compared with the NMR group or healthy individuals. Ischaemic MR in acute inferoposterior MI is related with worse lesions in MA geometry that cause insufficiency of mitral valve function.

Galactic Cosmic-ray Transport in the Global Heliosphere: A Four-Dimensional Stochastic Model

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Florinski, V.

2009-04-01

We study galactic cosmic-ray transport in the outer heliosphere and heliosheath using a newly developed transport model based on stochastic integration of the phase-space trajectories of Parker's equation. The model employs backward integration of the diffusion-convection transport equation using Ito calculus and is four-dimensional in space+momentum. We apply the model to the problem of galactic proton transport in the heliosphere during a negative solar minimum. Model results are compared with the Voyager measurements of galactic proton radial gradients and spectra in the heliosheath. We show that the heliosheath is not as efficient in diverting cosmic rays during solar minima as predicted by earlier two-dimensional models.

A validation study of the Four-Dimensional Symptom Questionnaire (4DSQ) in insurance medicine

NARCIS (Netherlands)

Langerak, W.; Langeland, W.; van Balkom, A.J.L.M.; Draisma, S.; Terluin, B.; Draijer, P.J.

2012-01-01

Objective: This study aimed to evaluate the criterion validity and the diagnostic accuracy of the Four-Dimensional Symptom Questionnaire (4DSQ) regarding the identification of depressive and anxiety disorders in an insurance medicine setting. Participants: Our sample consisted of 230 individuals who

Improving left ventricular segmentation in four-dimensional flow MRI using intramodality image registration for cardiac blood flow analysis.

Science.gov (United States)

Gupta, Vikas; Bustamante, Mariana; Fredriksson, Alexandru; Carlhäll, Carl-Johan; Ebbers, Tino

2018-01-01

Assessment of blood flow in the left ventricle using four-dimensional flow MRI requires accurate left ventricle segmentation that is often hampered by the low contrast between blood and the myocardium. The purpose of this work is to improve left-ventricular segmentation in four-dimensional flow MRI for reliable blood flow analysis. The left ventricle segmentations are first obtained using morphological cine-MRI with better in-plane resolution and contrast, and then aligned to four-dimensional flow MRI data. This alignment is, however, not trivial due to inter-slice misalignment errors caused by patient motion and respiratory drift during breath-hold based cine-MRI acquisition. A robust image registration based framework is proposed to mitigate such errors automatically. Data from 20 subjects, including healthy volunteers and patients, was used to evaluate its geometric accuracy and impact on blood flow analysis. High spatial correspondence was observed between manually and automatically aligned segmentations, and the improvements in alignment compared to uncorrected segmentations were significant (P  0.05). Our results demonstrate the efficacy of the proposed approach in improving left-ventricular segmentation in four-dimensional flow MRI, and its potential for reliable blood flow analysis. Magn Reson Med 79:554-560, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

A guideline update for the practice of echocardiography in the cardiac screening of sports participants: a joint policy statement from the British Society of Echocardiography and Cardiac Risk in the Young

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David Oxborough PhD

2018-03-01

Full Text Available Sudden cardiac death (SCD in an athlete is a rare but tragic event. In view of this, pre-participation cardiac screening is mandatory across many sporting disciplines to identify those athletes at risk. Echocardiography is a primary investigation utilized in the pre-participation setting and in 2013 the British Society of Echocardiography and Cardiac Risk in the Young produced a joint policy document providing guidance on the role of echocardiography in this setting. Recent developments in our understanding of the athlete’s heart and the application of echocardiography have prompted this 2018 update.

Evaluation of echocardiography in the management of elderly patients with heart failure.

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Hendry, A; Hacking, L; Langhorne, P; Vallance, R; MacDonald, J

1999-09-01

To determine the validity of a clinical diagnosis of systolic dysfunction in elderly patients with heart failure and assess the contribution of echocardiography to their management. 61 elderly patients with a diagnosis of heart failure in a geriatric assessment unit setting. Prospective study determining sensitivity, specificity and predictive values of a clinical and radiological diagnosis compared with echocardiographic standard. Proposed management was compared before and after echocardiography. Clinical assessment was highly sensitive (93%) but lacked specificity (32%). Combining radiological and clinical diagnoses increased specificity to 58%. Echocardiography revised the lead cardiac diagnosis for 28% of patients and influenced patient management plans for 41%. For elderly patients with heart failure, echocardiography improves diagnostic accuracy and identifies those patients with potential to benefit from angiotensin-converting enzyme inhibitors.

Intraoperative echocardiography of a dislodged Björk-Shiley mitral valve disc.

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Tanaka, M; Abe, T; Takeuchi, E; Watanabe, T; Tamaki, S

1991-02-01

The successful management of a patient who suffered an outlet strut fracture of a Björk-Shiley 60-degree convexo-concave mitral valve prosthesis is reported. Emergency operation was life-saving. Preoperative echocardiography assisted in making a prompt diagnosis, and intraoperative echocardiography allowed the detection and removal of the dislodged disc from the left ventricle at the time of the operation. The role of intraoperative echocardiography in the diagnosis of prosthetic strut fracture is emphasized.

Four-dimensional optoacoustic temperature mapping in laser-induced thermotherapy

Science.gov (United States)

Oyaga Landa, Francisco Javier; Deán-Ben, Xosé Luís.; Sroka, Ronald; Razansky, Daniel

2018-02-01

Photoablative laser therapy is in common use for selective destruction of malignant masses, vascular and brain abnormalities. Tissue ablation and coagulation are irreversible processes occurring shortly after crossing a certain thermal exposure threshold. As a result, accurate mapping of the temperature field is essential for optimizing the outcome of these clinical interventions. Here we demonstrate four-dimensional optoacoustic temperature mapping of the entire photoablated region. Accuracy of the method is investigated in tissue-mimicking phantom experiments. Deviations of the volumetric optoacoustic temperature readings provided at 40ms intervals remained below 10% for temperature elevations above 3°C, as validated by simultaneous thermocouple measurements. The excellent spatio-temporal resolution of the new temperature monitoring approach aims at improving safety and efficacy of laser-based photothermal procedures.

Factors associated with diagnostic discrepancy for left ventricular hypertrophy between electrocardiography and echocardiography

DEFF Research Database (Denmark)

Sandager Petersen, Søren; Reinholdt Pedersen, Line; Pareek, Manan

2017-01-01

(absolute value/cut-off value for LVH) were used as outcome variables in order to identify explanatory variables associated with diagnostic discrepancies between ECG and echocardiography. RESULTS: Of the 1382 subjects included, 77% did not display any signs of LVH, 6% had LVH defined by ECG only, 13% had...... LVH defined by echocardiography only, and 5% had LVH on both ECG and echocardiography. Older subjects and those with higher blood pressure and RWT were more likely to have a relatively greater LVMI on echocardiography than that predicted on ECG (odds ratio: 1.65 per 10 years (95% confidence interval...... and odds ratio: 1.41 (95% CI: 1.06-1.87), p = .02), but FPG did not independently influence discrepancy between ECG and echocardiography. CONCLUSION: Age, blood pressure, female sex, greater RWT and use of antihypertensive medication were associated with a greater risk of non-consistency between LVH...

Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure

Science.gov (United States)

Shojaeifard, Maryam; Ghaedian, Tahereh; Yaghoobi, Nahid; Malek, Hadi; Firoozabadi, Hasan; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amin, Ahmad; Azizian, Nasrin; Rastgou, Feridoon

2015-01-01

Background: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. Objectives: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. Patients and Methods: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. Results: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. Conclusions: Gated SPECT MPI has a good correlation with echocardiography for the measurement of left ventricular EF, EDV, and ESV in patients with severe heart failure. However, the absolute values of these functional parameters from echocardiography and gated

Intraoperative three-dimensional transesophageal echocardiography for assessing the defect geometries of mitral prosthetic paravalvular leak during transcatheter closure.

Science.gov (United States)

Wei, Jeng; Yin, Wei-Hsian; Lee, Yung-Tsai; Hsiung, Ming C; Tsai, Shen-Kou; Chuang, Yi Cheng; Ou, Ching-Huei; Chou, Yi-Pen

2015-03-01

Paravalvular leaks (PVLs) are a common complication of prosthetic valve replacement. Use of the transcatheter intervention technique is a suitable alternative in high-risk patients who may not tolerate repeat surgery. Common reasons for failure of this demanding intervention include poor imaging quality and unsuitable anatomy. The purpose of this study was to assess the usefulness and the incremental value of real-time three-dimensional (RT 3D) transesophageal echocardiography (TEE) over two-dimensional (2D) TEE findings in the evaluation of the geometry and track of mitral PVLs during transcatheter closure. Five patients with six mitral PVLs at high risk for repeat surgery underwent transcatheter leak closure. Intraoperative RT 3DTEE was used to assess the location, shape, number, and size of the defects. Transapical approaches were used in all cases with fluoroscopic and RT 3D TEE guidance of the wire and catheter, device positioning, and assessment of residual leak after the procedure. In all of the cases, defects with irregular crescent shapes and distorted tracks were clearly delineated by RT 3D TEE. This was compared to those results obtained through 2D TEE, which was unable to characterize the defects. Three cases showed small leaks, which were completely occluded with a patent ductus arteriosus (PDA) device in two cases, and a muscular ventricular septal defect (mVSD) occluder combined with coil devices in one case. One case involved a large leak and early device embolization of the muscular VSD occluder, which was removed surgically, and demonstrated a crescent-shaped defect. One patient had two releaks 2 months subsequent to the procedure due to two new extended leaks at the tails of the crescent-shaped defect. RT 3D TEE can clearly delineate the geometries of defects in their entirety, including shape, size, and location of the defect and track canal. It would also appear that RT 3D TEE is superior to 2D TEE in the process of guiding the wire through the

Transesophageal echocardiography for cardiac thromboembolic risk assessment in patients with severe, symptomatic aortic valve stenosis referred for potential transcatheter aortic valve implantation.

Science.gov (United States)

Lenders, Guy D; Paelinck, Bernard P; Wouters, Kristien; Claeys, Marc J; Rodrigus, Inez E; Van Herck, Paul L; Vrints, Christiaan J; Bosmans, Johan M

2013-05-15

Stroke is a devastating complication after transcatheter aortic valve implantation (TAVI) and might partially be related to cardiac embolization. The aim of this single-center prospective study was to determine the incidence of intracardiac thrombi and left atrial spontaneous echo contrast (SEC), both known predictors of cardiac embolic stroke, in patients referred for potential TAVI. One hundred four consecutive patients with severe symptomatic aortic valve stenosis and at high or very high risk for surgery were included and underwent transesophageal echocardiography. In 11 patients (10.6%), intracardiac thrombi were detected, and 25 patients (24%) showed dense grade 2 SEC. Atrial fibrillation (p risk patients with severe aortic valve stenosis referred for potential TAVI is high and can accurately be detected using transesophageal echocardiography. Systematic thromboembolic evaluation using transesophageal echocardiography is thus recommended in patients referred for TAVI. Copyright © 2013 Elsevier Inc. All rights reserved.

Spontaneous transition to a stochastic state in a four-dimensional Yang-Mills quantum theory

International Nuclear Information System (INIS)

Semikhatov, A.M.

1983-01-01

The quantum expectation values in a four-dimensional Yang-Mills theory are represented in each topological sector as expectation values over the diffusion which develops in the ''fourth'' Euclidean time. The Langevin equations of this diffusion are stochastic duality equations in the A 4 = 0 gauge

Four dimensional chaos and intermittency in a mesoscopic model of the electroencephalogram.

Science.gov (United States)

Dafilis, Mathew P; Frascoli, Federico; Cadusch, Peter J; Liley, David T J

2013-06-01

The occurrence of so-called four dimensional chaos in dynamical systems represented by coupled, nonlinear, ordinary differential equations is rarely reported in the literature. In this paper, we present evidence that Liley's mesoscopic theory of the electroencephalogram (EEG), which has been used to describe brain activity in a variety of clinically relevant contexts, possesses a chaotic attractor with a Kaplan-Yorke dimension significantly larger than three. This accounts for simple, high order chaos for a physiologically admissible parameter set. Whilst the Lyapunov spectrum of the attractor has only one positive exponent, the contracting dimensions are such that the integer part of the Kaplan-Yorke dimension is three, thus giving rise to four dimensional chaos. A one-parameter bifurcation analysis with respect to the parameter corresponding to extracortical input is conducted, with results indicating that the origin of chaos is due to an inverse period doubling cascade. Hence, in the vicinity of the high order, strange attractor, the model is shown to display intermittent behavior, with random alternations between oscillatory and chaotic regimes. This phenomenon represents a possible dynamical justification of some of the typical features of clinically established EEG traces, which can arise in the case of burst suppression in anesthesia and epileptic encephalopathies in early infancy.

Three-Dimensional Echocardiography-Derived Non-Invasive Right Ventricular Pressure-Volume Analysis.

Science.gov (United States)

Huang, Kuan-Chih; Lin, Lian-Yu; Hwang, Juey-Jen; Lin, Lung-Chun

2017-09-01

In patients with pulmonary hypertension, repeated evaluations of right ventricular (RV) function are still required for clinical decision making, but the invasive nature of current pressure-volume analysis makes conducting regular follow-ups in a clinical setting infeasible. We enrolled 12 patients with pulmonary arterial hypertension (PAH) and 10 with pulmonary venous hypertension (PVH) May 2016-October 2016. All patients underwent a clinically indicated right heart catheterization (RHC), from which the yielded right ventricular pressure recordings were conjugated with RV volume by 3-D echocardiography to generate a pressure-volume loop. A continuous-wave Doppler envelope of tricuspid regurgitation was transformed into a pressure gradient recording by the simplified Bernoulli equation, and then a systolic pressure gradient-volume (PG-V) diagram was generated from similar methods. The area enclosed by the pressure-volume loop was calculated to represent semi-invasive right ventricular stroke work (RVSW RHC ). The area between the PG-V diagram and x-axis was calculated to estimate non-invasive RVSW (RVSW echo ). Patients with PAH have higher RV pressure, lower pulmonary arterial wedge pressure and larger RV volume that was contributed by the dilation of RV mid-cavity minor dimension. We found no significant difference of traditional parameters between these two groups, but RVSW values were significantly higher in PAH patients. The RVSW values of these two methods were significantly correlated by the equation RVSW echo  = 0.8447 RVSW RHC  + 129.38 (R 2  = 0.9151, p rights reserved.

Left Ventricular Myocardial Deformation Parameters Are Affected by Coronary Slow Flow Phenomenon: A Study of Speckle Tracking Echocardiography.

Science.gov (United States)

Gulel, Okan; Akcay, Murat; Soylu, Korhan; Aksan, Gokhan; Yuksel, Serkan; Zengin, Halit; Meric, Murat; Sahin, Mahmut

2016-05-01

The coronary slow flow phenomenon (CSFP) is defined as a delayed distal vessel contrast opacification in the absence of obstructive epicardial coronary artery disease during coronary angiography. There is conflicting data in medical literature regarding the effects of CSFP on the left ventricular functions assessed by conventional echocardiography or tissue Doppler imaging. Therefore, we aimed to evaluate whether there is any abnormality in the myocardial deformation parameters (strain, strain rate (SR), rotation, twist) of the left ventricle obtained by speckle tracking echocardiography (STE) in patients with CSFP. Twenty patients with CSFP were included prospectively in the study. Another 20 patients with similar demographics and cardiovascular risk factors as well as normal coronary angiography were used as the control group. Two-dimensional echocardiographic images of the left ventricle from the apical long-axis, two-chamber, four-chamber, and parasternal short-axis views were used for STE analysis. The analysis of left ventricular circumferential deformation parameters showed that the averaged peak systolic strain, systolic SR, and early diastolic SR values were significantly lower in patients with CSFP (P = 0.009, P = 0.02, and P = 0.02, respectively). Among the left ventricular rotation and twist values, apical rotation was significantly lower in patients with CSFP (P = 0.02). Further, the mean thrombolysis in myocardial infarction frame count value was found to be negatively correlated with the averaged peak circumferential early diastolic SR (r = -0.35, P = 0.03). It was positively correlated with the averaged peak circumferential systolic strain (r = 0.47, P = 0.003) and circumferential systolic SR (r = 0.46, P = 0.005). Coronary slow flow phenomenon leads to significant alterations in the myocardial deformation parameters of the left ventricle as assessed by STE. Specifically, circumferential deformation parameters are affected in CSFP patients. © 2015

Strain Echocardiography Improves Risk Prediction of Ventricular Arrhythmias After Myocardial Infarction

DEFF Research Database (Denmark)

Haugaa, Kristina H; Grenne, Bjørnar L; Eek, Christian H

2013-01-01

The aim of this study was to test the hypothesis that strain echocardiography might improve arrhythmic risk stratification in patients after myocardial infarction (MI).......The aim of this study was to test the hypothesis that strain echocardiography might improve arrhythmic risk stratification in patients after myocardial infarction (MI)....

Four-dimensional gravity as an almost-Poisson system

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Ita, Eyo Eyo

2015-04-01

In this paper, we examine the phase space structure of a noncanonical formulation of four-dimensional gravity referred to as the Instanton representation of Plebanski gravity (IRPG). The typical Hamiltonian (symplectic) approach leads to an obstruction to the definition of a symplectic structure on the full phase space of the IRPG. We circumvent this obstruction, using the Lagrange equations of motion, to find the appropriate generalization of the Poisson bracket. It is shown that the IRPG does not support a Poisson bracket except on the vector constraint surface. Yet there exists a fundamental bilinear operation on its phase space which produces the correct equations of motion and induces the correct transformation properties of the basic fields. This bilinear operation is known as the almost-Poisson bracket, which fails to satisfy the Jacobi identity and in this case also the condition of antisymmetry. We place these results into the overall context of nonsymplectic systems.

Exercise echocardiography for structural heart disease.

Science.gov (United States)

Izumo, Masaki; Akashi, Yoshihiro J

2016-03-01

Since the introduction of transcatheter structural heart intervention, the term "structural heart disease" has been widely used in the field of cardiology. Structural heart disease refers to congenital heart disease, valvular heart disease, and cardiomyopathy. In structural heart disease, valvular heart disease is frequently identified in the elderly. Of note, the number of patients who suffer from aortic stenosis (AS) and mitral regurgitation (MR) is increasing in developed countries because of the aging of the populations. Transcatheter aortic valve replacement and percutaneous mitral valve repair has been widely used for AS and MR, individually. Echocardiography is the gold standard modality for initial diagnosis and subsequent evaluation of AS and MR, although the difficulties in assessing patients with these diseases still remain. Here, we review the clinical usefulness and prognostic impact of exercise echocardiography on structural heart disease, particularly on AS and MR.

Non-critical string duals of four-dimensional CFTs with fundamental matter

International Nuclear Information System (INIS)

Bigazzi, F.; Casero, R.; Paredes, A.; Cotrone, A.L.

2006-01-01

The two-derivative approximation to non-critical strings is used as a qualitative tool to find solutions dual to four dimensional CFTs with matter in the fundamental. Two solutions are discussed: an AdS 5 x S 3 , which is dual to an N=1 SCFT only for a ratio of N f /N c and an AdS 5 which is proposed to be dual to N=0 QCD in the conformal window. All solutions have curvatures of the order of the string scale. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Effect of Novel Amplitude/Phase Binning Algorithm on Commercial Four-Dimensional Computed Tomography Quality

International Nuclear Information System (INIS)

Olsen, Jeffrey R.; Lu Wei; Hubenschmidt, James P.; Nystrom, Michelle M.; Klahr, Paul; Bradley, Jeffrey D.; Low, Daniel A.; Parikh, Parag J.

2008-01-01

Purpose: Respiratory motion is a significant source of anatomic uncertainty in radiotherapy planning and can result in errors of portal size and the subsequent radiation dose. Although four-dimensional computed tomography allows for more accurate analysis of the respiratory cycle, breathing irregularities during data acquisition can cause considerable image distortions. The aim of this study was to examine the effect of respiratory irregularities on four-dimensional computed tomography, and to evaluate a novel image reconstruction algorithm using percentile-based tagging of the respiratory cycle. Methods and Materials: Respiratory-correlated helical computed tomography scans were acquired for 11 consecutive patients. The inspiration and expiration data sets were reconstructed using the default phase-based method, as well as a novel respiration percentile-based method with patient-specific metrics to define the ranges of the reconstruction. The image output was analyzed in a blinded fashion for the phase- and percentile-based reconstructions to determine the prevalence and severity of the image artifacts. Results: The percentile-based algorithm resulted in a significant reduction in artifact severity compared with the phase-based algorithm, although the overall artifact prevalence did not differ between the two algorithms. The magnitude of differences in respiratory tag placement between the phase- and percentile-based algorithms correlated with the presence of image artifacts. Conclusion: The results of our study have indicated that our novel four-dimensional computed tomography reconstruction method could be useful in detecting clinically relevant image distortions that might otherwise go unnoticed and to reduce the image distortion associated with some respiratory irregularities. Additional work is necessary to assess the clinical impact on areas of possible irregular breathing

Multidetector CT evaluation of total anomalous pulmonary venous connections: comparison with echocardiography

International Nuclear Information System (INIS)

Oh, Ki Ho; Choo, Ki Seok; Lim, Soo Jin; Lee, Hyoung Doo; Park, Ji Ae; Jo, Min Jung; Sung, Si Chan; Chang, Yun Hee; Jeong, Dong Wook; Kim, Siho

2009-01-01

Although echocardiography is the first-line imaging modality in the diagnosis of total anomalous pulmonary venous connection (TAPVC), multidetector CT (MDCT) could have advantages in the diagnosis of TAPVC in certain cases. To compare MDCT with echocardiography in the evaluation of TAPVC. Enrolled in the study were 23 patients with surgically proven TAPVC. The echocardiography and MDCT findings were independently interpreted by a paediatric cardiologist and cardiac radiologist in terms of: (1) the drainage site of the common pulmonary vein, (2) stenosis of the vertical vein, and (3) the course of the atypical vessel into the systemic vein in the case of vertical vein stenosis. The findings from both modalities were correlated with the results obtained at surgery (n=22) or autopsy (n=1). In all patients, MDCT correctly depicted the drainage site of the common pulmonary vein, stenosis of the vertical vein and the course of the atypical vessel into the systemic vein (sensitivity 100%, specificity 100%). The specificity of echocardiography was 100% for the three defined findings. The sensitivity of echocardiography, however, was 87%, 71% and 0%, respectively. MDCT can facilitate the diagnosis of TAPVC in certain cases. (orig.)

Mass, angular momentum and thermodynamics in four-dimensional Kerr-AdS black holes

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Olea, Rodrigo [Departamento de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile)

2005-06-01

In this paper, the connection between the Lorentz-covariant counterterms that regularize the four-dimensional AdS gravity action and topological invariants is explored. It is shown that demanding the spacetime to have a negative constant curvature in the asymptotic region permits the explicit construction of such series of boundary terms. The orthonormal frame is adapted to appropriately describe the boundary geometry and, as a result, the boundary term can be expressed as a functional of the boundary metric, extrinsic curvature and intrinsic curvature. This choice also allows to write down the background-independent Noether charges associated to asymptotic symmetries in standard tensorial formalism. The absence of the Gibbons-Hawking term is a consequence of an action principle based on a boundary condition different than Dirichlet on the metric. This argument makes plausible the idea of regarding this approach as an alternative regularization scheme for AdS gravity in all even dimensions, different than the standard counterterms prescription. As an illustration of the finiteness of the charges and the euclidean action in this framework, the conserved quantities and black hole entropy for four-dimensional Kerr-AdS are computed.

Quality Assurance Challenges for Motion-Adaptive Radiation Therapy: Gating, Breath Holding, and Four-Dimensional Computed Tomography

International Nuclear Information System (INIS)

Jiang, Steve B.; Wolfgang, John; Mageras, Gig S.

2008-01-01

Compared with conventional three-dimensional (3D) conformal radiation therapy and intensity-modulated radiation therapy treatments, quality assurance (QA) for motion-adaptive radiation therapy involves various challenges because of the added temporal dimension. Here we discuss those challenges for three specific techniques related to motion-adaptive therapy: namely respiratory gating, breath holding, and four-dimensional computed tomography. Similar to the introduction of any other new technologies in clinical practice, typical QA measures should be taken for these techniques also, including initial testing of equipment and clinical procedures, as well as frequent QA examinations during the early stage of implementation. Here, rather than covering every QA aspect in depth, we focus on some major QA challenges. The biggest QA challenge for gating and breath holding is how to ensure treatment accuracy when internal target position is predicted using external surrogates. Recommended QA measures for each component of treatment, including simulation, planning, patient positioning, and treatment delivery and verification, are discussed. For four-dimensional computed tomography, some major QA challenges have also been discussed

Left Ventricular Function after Arterial Switch Operation as Assessed by Two-Dimensional Speckle-Tracking Echocardiography in Patients with Simple Transposition of the Great Arteries.

Science.gov (United States)

Malakan Rad, Elaheh; Ghandi, Yazdan; Kocharian, Armen; Mirzaaghayan, Mohammadreza

2016-07-06

Background: The late postoperative course for children with transposition of the great arteries (TGA) with an intact ventricular septum (IVS) is very important because the coronary arteries may be at risk of damage during arterial switch operation (ASO). We sought to investigate left ventricular function in patients with TGA/IVS by echocardiography. Methods: From March 2011 to December 2012, totally 20 infants (12 males and 8 females) with TGA/IVS were evaluated via 2-dimensional speckle-tracking echocardiography (2D STE) more than 6 months after they underwent ASO. A control group of age-matched infants and children was also studied. Left ventricular longitudinal strain (S), strain rate (SR), time to peak systolic longitudinal strain (TPS), and time to peak systolic longitudinal strain rate (TPSR) were measured and compared between the 2 groups. Results: Mean ± SD of age at the time of study in the patients with TGA/IVS was 15 ± 5 months, and also age at the time of ASO was 12 ± 3 days. Weight was 3.13 ± 0.07 kg at birth and 8.83 ± 1.57 kg at the time of ASO. Global strain (S), Time to peak strain rate (TPSR), and Time to peak strain (TPS) were not significantly different between the 2 groups, whereas global strain rate (SR) was significantly different (p value < 0.001). In the 3-chamber view, the values of S in the lateral, septal, inferior, and anteroseptal walls were significantly different between the 2 groups (p value < 0.001), and SR in the posterior wall was significantly different between the 2 groups (p value < 0.001). There were no positive correlations between S and SR in terms of the variables of heart rate, total cardiopulmonary bypass time, and aortic cross-clamp time. There were no statistically significant differences between the 2 groups regarding S, SR, TPS, and TPSR in the anteroseptal and posterior walls in the 3-chamber view and in the lateral and septal walls in the 4-chamber view. Conclusion: We showed that between 6 and 18 months after

Standard echocardiography versus handheld echocardiography for the detection of subclinical rheumatic heart disease: protocol for a systematic review.

Science.gov (United States)

Telford, Lisa H; Abdullahi, Leila H; Ochodo, Eleanor A; Zühlke, Liesl J; Engel, Mark E

2018-02-10

Rheumatic heart disease (RHD) is a preventable and treatable chronic condition which persists in many developing countries largely affecting impoverished populations. Handheld echocardiography presents an opportunity to address the need for more cost-effective methods of diagnosing RHD in developing countries, where the disease continues to carry high rates of morbidity and mortality. Preliminary studies have demonstrated moderate sensitivity as well as high specificity and diagnostic odds for detecting RHD in asymptomatic patients. We describe a protocol for a systematic review on the diagnostic performance of handheld echocardiography compared to standard echocardiography using the 2012 World Heart Federation criteria for diagnosing subclinical RHD. Electronic databases including PubMed, Scopus, Web of Science and EBSCOhost as well as reference lists and citations of relevant articles will be searched from 2012 to date using a predefined strategy incorporating a combination of Medical Subject Heading terms and keywords. The methodological validity and quality of studies deemed eligible for inclusion will be assessed against review specific Quality Assessment of Diagnostic Accuracy Studies 2 criteria and information on metrics of diagnostic accuracy and demographics extracted. Forest plots of sensitivity and specificity as well as scatter plots in receiver operating characteristic (ROC) space will be used to investigate heterogeneity. If possible, a meta-analysis will be conducted to produce summary results of sensitivity and specificity using the Hierarchical Summary ROC method. In addition, a sensitivity analysis will be conducted to investigate the effect of studies with a high risk of bias. Ethics approval is not required for this systematic review of previously published literature. The planned review will provide a summary of the diagnostic accuracy of handheld echocardiography. Results may feed into evidence-based guidelines and should the findings of this

Model-based image reconstruction for four-dimensional PET

International Nuclear Information System (INIS)

Li Tianfang; Thorndyke, Brian; Schreibmann, Eduard; Yang Yong; Xing Lei

2006-01-01

Positron emission tonography (PET) is useful in diagnosis and radiation treatment planning for a variety of cancers. For patients with cancers in thoracic or upper abdominal region, the respiratory motion produces large distortions in the tumor shape and size, affecting the accuracy in both diagnosis and treatment. Four-dimensional (4D) (gated) PET aims to reduce the motion artifacts and to provide accurate measurement of the tumor volume and the tracer concentration. A major issue in 4D PET is the lack of statistics. Since the collected photons are divided into several frames in the 4D PET scan, the quality of each reconstructed frame degrades as the number of frames increases. The increased noise in each frame heavily degrades the quantitative accuracy of the PET imaging. In this work, we propose a method to enhance the performance of 4D PET by developing a new technique of 4D PET reconstruction with incorporation of an organ motion model derived from 4D-CT images. The method is based on the well-known maximum-likelihood expectation-maximization (ML-EM) algorithm. During the processes of forward- and backward-projection in the ML-EM iterations, all projection data acquired at different phases are combined together to update the emission map with the aid of deformable model, the statistics is therefore greatly improved. The proposed algorithm was first evaluated with computer simulations using a mathematical dynamic phantom. Experiment with a moving physical phantom was then carried out to demonstrate the accuracy of the proposed method and the increase of signal-to-noise ratio over three-dimensional PET. Finally, the 4D PET reconstruction was applied to a patient case

Structures of larger proteins in solution: Three- and four-dimensional heteronuclear NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Gronenborn, A.M.; Clore, G.M. [National Institutes of Health, Bethesda, MD (United States)

1994-12-01

Complete understanding of a protein`s function and mechanism of action can only be achieved with a knowledge of its three-dimensional structure at atomic resolution. At present, there are two methods available for determining such structures. The first method, which has been established for many years, is x-ray diffraction of protein single crystals. The second method has blossomed only in the last 5 years and is based on the application of nuclear magnetic resonance (NMR) spectroscopy to proteins in solution. This review paper describes three- and four-dimensional NMR methods applied to protein structure determination and was adapted from Clore and Gronenborn. The review focuses on the underlying principals and practice of multidimensional NMR and the structural information obtained.

Four-Dimensional CT of the Diaphragm in Children: Initial Experience

Science.gov (United States)

2018-01-01

Objective To evaluate the technical feasibility of four-dimensional (4D) CT for the functional evaluation of the pediatric diaphragm. Materials and Methods In 22 consecutive children (median age 3.5 months, age range 3 days–3 years), 4D CT was performed to assess diaphragm motion. Diaphragm abnormalities were qualitatively evaluated and diaphragm motion was quantitatively measured on 4D CT. Lung density changes between peak inspiration and expiration were measured in the basal lung parenchyma. The diaphragm motions and lung density changes measured on 4D CT were compared between various diaphragm conditions. In 11 of the 22 children, chest sonography was available for comparison. Results Four-dimensional CT demonstrated normal diaphragm (n = 8), paralysis (n = 10), eventration (n = 3), and diffusely decreased motion (n = 1). Chest sonography demonstrated normal diaphragm (n = 2), paralysis (n = 6), eventration (n = 2), and right pleural effusion (n = 1). The sonographic findings were concordant with the 4D CT findings in 90.9% (10/11) of the patients. In diaphragm paralysis, the affected diaphragm motion was significantly decreased compared with the contralateral normal diaphragm motion (−1.1 ± 2.2 mm vs. 7.6 ± 3.8 mm, p = 0.005). The normal diaphragms showed significantly greater motion than the paralyzed diaphragms (4.5 ± 2.1 mm vs. −1.1 ± 2.2 mm, p Hounsfield units [HU] vs. 180 ± 71 HU, p = 0.03), while no significant differences were found between the normal diaphragms and the paralyzed diaphragms (136 ± 66 HU vs. 89 ± 73 HU, p = 0.1) or between the normal diaphragms and the contralateral normal diaphragms in paralysis (136 ± 66 HU vs. 180 ± 71 HU, p = 0.1). Conclusion The functional evaluation of the pediatric diaphragm is feasible with 4D CT in select children. PMID:29354007

An accessible four-dimensional treatment of Maxwell's equations in terms of differential forms

International Nuclear Information System (INIS)

Sá, Lucas

2017-01-01

Maxwell’s equations are derived in terms of differential forms in the four-dimensional Minkowski representation, starting from the three-dimensional vector calculus differential version of these equations. Introducing all the mathematical and physical concepts needed (including the tool of differential forms), using only knowledge of elementary vector calculus and the local vector version of Maxwell’s equations, the equations are reduced to a simple and elegant set of two equations for a unified quantity, the electromagnetic field. The treatment should be accessible for students taking a first course on electromagnetism. (paper)

Universal time versus relativistic time in four-dimensional symmetry framework

International Nuclear Information System (INIS)

Chiu, C.B.; Hsu, J.P.; Sherry, T.N.

1976-12-01

A new four-dimensional symmetry framework with a universal time is investigated which can be realized by a radioactive clock--the measured survival fraction of unstable particles gives the elapsed time. The world picture turns out to be quite different from that in special relativity. The general space-light transformation and the nonuniversal speed of light in this framework are discussed. The difference between the one-way speed and the two-way speed of a light signal is considered in detail. Moreover, the discussion sheds light on the connection between the universality of the light speed and the clock which does not read universal time. The relation with special relativity theory is examined in a few cases

The Role of Echocardiography in Coronary Artery Disease and Acute Myocardial Infarction

Science.gov (United States)

Esmaeilzadeh, Maryam; Parsaee, Mozhgan; Maleki, Majid

2013-01-01

Echocardiography is a non-invasive diagnostic technique which provides information regarding cardiac function and hemodynamics. It is the most frequently used cardiovascular diagnostic test after electrocardiography and chest X-ray. However, in a patient with acute chest pain, Transthoracic Echocardiography is essential both for diagnosing acute coronary syndrome, zeroing on the evaluation of ventricular function and the presence of regional wall motion abnormalities, and for ruling out other etiologies of acute chest pain or dyspnea, including aortic dissection and pericardial effusion. Echocardiography is a versatile imaging modality for the management of patients with chest pain and assessment of left ventricular systolic function, diastolic function, and even myocardial and coronary perfusion and is, therefore, useful in the diagnosis and triage of patients with acute chest pain or dyspnea. This review has focused on the current applications of echocardiography in patients with coronary artery disease and myocardial infarction. PMID:23646042

Cardiac imaging using 256-detector row four-dimensional CT. Preliminary clinical report

International Nuclear Information System (INIS)

Kido, Teruhito; Kurata, Akira; Higashino, Hiroshi

2007-01-01

Along with the increase of detector rows on the z-axis and a faster gantry rotation speed, the spatial and temporal resolutions of the multislice computed tomography (CT) have been improved for noninvasive coronary artery imaging. We investigated the feasibility of the second specification prototype 256-detector row four-dimensional CT for assessing coronary artery and cardiac function. The subjects were five patients with coronary artery disease. Contrast medium (40-60 ml) was intravenously administered at the rate of 3-4 ml/s. The patient's whole heart was scanned for 1.5 s to cover at least one cardiac cycle during breathholding without electrocardiographic gating. Parameters used were 0.5 mm slice thickness, 0.5 s/rotation, 120 Kv, and 350 mA, with a half-scan reconstruction algorithm (temporal resolution 250 ms). Twenty-six transaxial datasets were reconstructed at intervals of 50 ms. The assessability of the coronary arteries in American Heart Association (AHA) segments 1, 2, 3, 5, 6, 7, 9, and 11 was visually evaluated, resulting in 29 of 32 (90.9%) segments being assessable. Functional assessment was also performed using animated movies without banding artifacts in all cases. The 256-detector row four-dimensional CT can assess the coronary artery and cardiac function using data during 1.5 s without banding artifacts. (author)

Effectiveness of simulator-based echocardiography training of noncardiologists in congenital heart diseases.

Science.gov (United States)

Wagner, Robert; Razek, Vit; Gräfe, Florentine; Berlage, Thomas; Janoušek, Jan; Daehnert, Ingo; Weidenbach, Michael

2013-07-01

Congenital heart diseases (CHD) are responsible for substantial morbidity and mortality in neonates. The preliminary diagnosis often is made by noncardiologists. For this reason, there is a huge demand of training in echocardiography of CHD. This is difficult to achieve due to limited resources of specialized centers. The goal of this study was to investigate the training effect of the echocardiography simulator EchoCom on trainee's ability to diagnose CHD. We enrolled 10 residents for simulator-based training in echocardiography of CHD. All participants were instructed on the simulator's basic handling and had one hour to scan the first 9 datasets information (ventricular septal defect, atrial septal defect, atrioventricular septal defect, Tetralogy of Fallot, transposition of great arteries, congenital corrected transposition of great arteries, common arterial trunk, hypoplastic left heart syndrome, normal anatomy) and establish a diagnosis. No help was given except for support regarding simulator related issues. Afterward, 2 rounds of structured simulator based echocardiography training focused on echocardiographic anatomy, spatial orientation, standard views, and echocardiographic anatomy of different CHD followed. All participants completed a standardized questionnaire containing 10 multiple-choice (MC) questions focusing on basic theoretical knowledge in echocardiographic anatomy and common CHD. Almost all of the residents invited from the affiliated children's hospital had little (20%) or no experience (80%) in echocardiography of CHD. Their Pretest and Posttest scores showed significant improvement for both, MC test and performance test, respectively. Our study showed that simulator-based training in echocardiography in CHD could be very effective and may assist with training outside the scope of CHD. © 2013, Wiley Periodicals, Inc.

Dobutamine stress echocardiography in healthy adult male rats

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Couet Jacques

2005-10-01

Full Text Available Abstract Background Dobutamine stress echocardiography is used to investigate a wide variety of heart diseases in humans. Dobutamine stress echocardiography has also been used in animal models of heart disease despite the facts that the normal response of healthy rat hearts to this type of pharmacological stress testing is unknown. This study was performed to assess this normal response. Methods 15 normal adult male Wistar rats were evaluated. Increasing doses of dobutamine were infused intravenously under continuous imaging of the heart by a 12 MHz ultrasound probe. Results Dobutamine stress echocardiography reduced gradually LV diastolic and systolic dimensions. Ejection fraction increased by a mean of +24% vs. baseline. Heart rate increased progressively without reaching a plateau. Changes in LV dimensions and ejection fraction reached a plateau after a mean of 4 minutes at a constant infusion rate. Conclusion DSE can be easily performed in rats. The normal response is an increase in heart rate and ejection fraction and a decrease in LV dimensions. A plateau in echocardiographic measurements is obtained after 4 minutes of a constant infusion rate in most animals.

The accuracy of echocardiography versus surgical and pathological classification of patients with ruptured mitral chordae tendineae: a large study in a Chinese cardiovascular center

Science.gov (United States)

2011-01-01

Background The accuracy of echocardiography versus surgical and pathological classification of patients with ruptured mitral chordae tendineae (RMCT) has not yet been investigated with a large study. Methods Clinical, hemodynamic, surgical, and pathological findings were reviewed for 242 patients with a preoperative diagnosis of RMCT that required mitral valvular surgery. Subjects were consecutive in-patients at Fuwai Hospital in 2002-2008. Patients were evaluated by thoracic echocardiography (TTE) and transesophageal echocardiography (TEE). RMCT cases were classified by location as anterior or posterior, and classified by degree as partial or complete RMCT, according to surgical findings. RMCT cases were also classified by pathology into four groups: myxomatous degeneration, chronic rheumatic valvulitis (CRV), infective endocarditis and others. Results Echocardiography showed that most patients had a flail mitral valve, moderate to severe mitral regurgitation, a dilated heart chamber, mild to moderate pulmonary artery hypertension and good heart function. The diagnostic accuracy for RMCT was 96.7% for TTE and 100% for TEE compared with surgical findings. Preliminary experiments demonstrated that the sensitivity and specificity of diagnosing anterior, posterior and partial RMCT were high, but the sensitivity of diagnosing complete RMCT was low. Surgical procedures for RMCT depended on the location of ruptured chordae tendineae, with no relationship between surgical procedure and complete or partial RMCT. The echocardiographic characteristics of RMCT included valvular thickening, extended subvalvular chordae, echo enhancement, abnormal echo or vegetation, combined with aortic valve damage in the four groups classified by pathology. The incidence of extended subvalvular chordae in the myxomatous group was higher than that in the other groups, and valve thickening in combination with AV damage in the CRV group was higher than that in the other groups. Infective

4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

Energy Technology Data Exchange (ETDEWEB)

Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

2015-06-15

Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

Fusion of three-dimensional X-ray angiography and three-dimensional echocardiography

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Rasche, Volker [University of Ulm, Department of Internal Medicine II, Ulm (Germany); Philips Medical Systems, Bothell, WA (United States); Mansour, Moussa; Reddy, Vivek; Singh, Jagmeet P.; Ruskin, Jeremy [Massachusetts General Hospital, Harvard Medical School, Cardiac Arrhythmia Service, Boston, MA (United States); Qureshi, Answer [Massachusetts General Hospital, Harvard Medical School, Echocardiography, Boston, MA (United States); Manzke, Robert; Sokka, Sham [Philips Research North America, Clinical Sites Research, Briacliff Manor, NY (United States)

2008-03-15

Cardiovascular intervention guidance requires knowledge of heart function relative to its blood supply or venous drainage. Functional and vascular anatomic data are usually generated on different imaging systems, so fusion of the data is necessary to simultaneously visualize the results for intervention planning and guidance. The objective of this work is to establish the feasibility of fusing volumetric ultrasound (U/S) data with three-dimensional (3D) X-ray imaging data for visualization of cardiac morphology, function and coronary venous drainage. Temporally resolved U/S volume data was registered with the 3D reconstruction of vascular structures derived from X-ray modeling and reconstruction. U/S image registration was obtained by optical tracking fiducial markers with simultaneous X-ray imaging. The proposed technique was applied to phantom data for accuracy assessment of the registration process and to biventricular pacemaker implantation as clinical example. Fusion of U/S data with 3D X-ray reconstruction data produced an RMS registration error below 2 mm. Preliminary clinical feasibility of U/S-derived data synchronously with X-ray derived 3D coronary venography was established. This technique can be applied for fusion of functional U/S data with 3D anatomic X-ray data of the coronary veins during a biventricular pacemaker implantation procedures. (orig.)

Fusion of three-dimensional X-ray angiography and three-dimensional echocardiography

International Nuclear Information System (INIS)

Rasche, Volker; Mansour, Moussa; Reddy, Vivek; Singh, Jagmeet P.; Ruskin, Jeremy; Qureshi, Answer; Manzke, Robert; Sokka, Sham

2008-01-01

Cardiovascular intervention guidance requires knowledge of heart function relative to its blood supply or venous drainage. Functional and vascular anatomic data are usually generated on different imaging systems, so fusion of the data is necessary to simultaneously visualize the results for intervention planning and guidance. The objective of this work is to establish the feasibility of fusing volumetric ultrasound (U/S) data with three-dimensional (3D) X-ray imaging data for visualization of cardiac morphology, function and coronary venous drainage. Temporally resolved U/S volume data was registered with the 3D reconstruction of vascular structures derived from X-ray modeling and reconstruction. U/S image registration was obtained by optical tracking fiducial markers with simultaneous X-ray imaging. The proposed technique was applied to phantom data for accuracy assessment of the registration process and to biventricular pacemaker implantation as clinical example. Fusion of U/S data with 3D X-ray reconstruction data produced an RMS registration error below 2 mm. Preliminary clinical feasibility of U/S-derived data synchronously with X-ray derived 3D coronary venography was established. This technique can be applied for fusion of functional U/S data with 3D anatomic X-ray data of the coronary veins during a biventricular pacemaker implantation procedures. (orig.)

Evaluation of Computer-Based Training for Health Workers in Echocardiography for RHD.

Science.gov (United States)

Engelman, Daniel; Okello, Emmy; Beaton, Andrea; Selnow, Gary; Remenyi, Bo; Watson, Caroline; Longenecker, Chris T; Sable, Craig; Steer, Andrew C

2017-03-01

The implementation of screening for rheumatic heart disease at a population-scale would require a considerable increase in human resources. Training nonexpert staff in echocardiography requires appropriate methods and materials. This pre/post study aims to measure the change in the knowledge and confidence of a group of health workers after a computer-assisted training intervention in basic echocardiography for rheumatic heart disease. A syllabus of self-guided, computer-based modules to train nonexpert health workers in basic echocardiography for rheumatic heart disease was developed. Thirty-eight health workers from Uganda participated in the training. Using a pre/post design, identical test instruments were administered before and after the training intervention, assessing the knowledge (using multiple-choice questions) and confidence (using Likert scale questions) in clinical science and echocardiography. The mean total score on knowledge tests rose from 44.8% to 85.4% (mean difference: 40.6%, 95% confidence interval [CI]: 35.4% to 45.8%), with strong evidence for an increase in scores across all knowledge theme areas (p science (difference: 7.1, 95% CI: 6.2 to 8.0; p computer-assisted learning may reduce the human resource requirements for training staff in echocardiography. Copyright © 2016 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.

Gravitational matter-antimatter asymmetry and four-dimensional Yang-Mills gauge symmetry

Science.gov (United States)

Hsu, J. P.

1981-01-01

A formulation of gravity based on the maximum four-dimensional Yang-Mills gauge symmetry is studied. The theory predicts that the gravitational force inside matter (fermions) is different from that inside antimatter. This difference could lead to the cosmic separation of matter and antimatter in the evolution of the universe. Moreover, a new gravitational long-range spin-force between two fermions is predicted, in addition to the usual Newtonian force. The geometrical foundation of such a gravitational theory is the Riemann-Cartan geometry, in which there is a torsion. The results of the theory for weak fields are consistent with previous experiments.

High-precision two-dimensional atom localization from four-wave mixing in a double-Λ four-level atomic system

Science.gov (United States)

Shui, Tao; Yang, Wen-Xing; Chen, Ai-Xi; Liu, Shaopeng; Li, Ling; Zhu, Zhonghu

2018-03-01

We propose a scheme for high-precision two-dimensional (2D) atom localization via the four-wave mixing (FWM) in a four-level double-Λ atomic system. Due to the position-dependent atom-field interaction, the 2D position information of the atoms can be directly determined by the measurement of the normalized light intensity of output FWM-generated field. We further show that, when the position-dependent generated FWM field has become sufficiently intense, efficient back-coupling to the FWM generating state becomes important. This back-coupling pathway leads to competitive multiphoton destructive interference of the FWM generating state by three supplied and one internally generated fields. We find that the precision of 2D atom localization can be improved significantly by the multiphoton destructive interference and depends sensitively on the frequency detunings and the pump field intensity. Interestingly enough, we show that adjusting the frequency detunings and the pump field intensity can modify significantly the FWM efficiency, and consequently lead to a redistribution of the atoms. As a result, the atom can be localized in one of four quadrants with holding the precision of atom localization.

Dimensional Reduction of N=1, E_8 SYM over SU(3)/U(1) x U(1) x Z_3 and its four-dimensional effective action

CERN Document Server

Irges, Nikos; Zoupanos, George

2011-01-01

We present an extension of the Standard Model inspired by the E_8 x E_8 Heterotic String. In order that a reasonable effective Lagrangian is presented we neglect everything else other than the ten-dimensional N=1 supersymmetric Yang-Mills sector associated with one of the gauge factors and certain couplings necessary for anomaly cancellation. We consider a compactified space-time M_4 x B_0 / Z_3, where B_0 is the nearly-Kaehler manifold SU(3)/U(1) x U(1) and Z_3 is a freely acting discrete group on B_0. Then we reduce dimensionally the E_8 on this manifold and we employ the Wilson flux mechanism leading in four dimensions to an SU(3)^3 gauge theory with the spectrum of a N=1 supersymmetric theory. We compute the effective four-dimensional Lagrangian and demonstrate that an extension of the Standard Model is obtained with interesting features including a conserved baryon number and fixed tree level Yukawa couplings and scalar potential. The spectrum contains new states such as right handed neutrinos and heavy ...

Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia

International Nuclear Information System (INIS)

Perin, E.C.; Moore, W.; Blume, M.; Hernandez, G.; Dhekne, R.; DeCastro, C.M.

1991-01-01

After an intravenous infusion of dipyridamole (0.56 mg/kg), the authors performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, they found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease

Outcomes in Asymptomatic Severe Aortic Stenosis With Preserved Ejection Fraction Undergoing Rest and Treadmill Stress Echocardiography.

Science.gov (United States)

Huded, Chetan P; Masri, Ahmad; Kusunose, Kenya; Goodman, Andrew L; Grimm, Richard A; Gillinov, A Marc; Johnston, Douglas R; Rodriguez, L Leonardo; Popovic, Zoran B; Svensson, Lars G; Griffin, Brian P; Desai, Milind Y

2018-04-12

In asymptomatic patients with severe aortic stenosis and preserved left ventricular ejection fraction, we sought to assess the incremental prognostic value of resting valvuloarterial impedence (Zva) and left ventricular global longitudinal strain (LV-GLS) to treadmill stress echocardiography. We studied 504 such patients (66±12 years, 78% men, 32% with coronary artery disease who underwent treadmill stress echocardiography between 2001 and 2012. Clinical and exercise variables (% of age-sex predicted metabolic equivalents [%AGP-METs]) were recorded. Resting Zva ([systolic arterial pressure+mean aortic valve gradient]/[LV-stroke volume index]) and LV-GLS (measured offline using Velocity Vector Imaging, Siemens) were obtained from the baseline resting echocardiogram. Death was the primary outcome. There were no major adverse cardiac events during treadmill stress echocardiography. Indexed aortic valve area, Zva, and LV-GLS were 0.46±0.1 cm 2 /m 2 , 4.5±0.9 mm Hg/mL per m 2 and -16±4%, respectively; only 50% achieved >100% AGP-METs. Sixty-four percent underwent aortic valve replacement. Death occurred in 164 (33%) patients over 8.9±3.6 years (2 within 30 days of aortic valve replacement). On multivariable Cox survival analysis, higher Society of Thoracic Surgeons score (hazard ratio or HR 1.06), lower % AGP-METS (HR 1.16), higher Zva (HR 1.25) and lower LV-GLS (HR 1.12) were associated with higher longer-term mortality, while aortic valve replacement (HR 0.45) was associated with improved survival (all P statistic from 0.65 to 0.69 and 0.75, respectively, both P stress echocardiography, LV-GLS and ZVa offer incremental prognostic value. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Automatic detection of end-diastole and end-systole from echocardiography images using manifold learning

International Nuclear Information System (INIS)

Gifani, Parisa; Behnam, Hamid; Shalbaf, Ahmad; Sani, Zahra Alizadeh

2010-01-01

The automatic detection of end-diastole and end-systole frames of echocardiography images is the first step for calculation of the ejection fraction, stroke volume and some other features related to heart motion abnormalities. In this paper, the manifold learning algorithm is applied on 2D echocardiography images to find out the relationship between the frames of one cycle of heart motion. By this approach the nonlinear embedded information in sequential images is represented in a two-dimensional manifold by the LLE algorithm and each image is depicted by a point on reconstructed manifold. There are three dense regions on the manifold which correspond to the three phases of cardiac cycle ('isovolumetric contraction', 'isovolumetric relaxation', 'reduced filling'), wherein there is no prominent change in ventricular volume. By the fact that the end-systolic and end-diastolic frames are in isovolumic phases of the cardiac cycle, the dense regions can be used to find these frames. By calculating the distance between consecutive points in the manifold, the isovolumic frames are mapped on the three minimums of the distance diagrams which were used to select the corresponding images. The minimum correlation between these images leads to detection of end-systole and end-diastole frames. The results on six healthy volunteers have been validated by an experienced echo cardiologist and depict the usefulness of the presented method

Investigation of a four-body coupling in the one-dimensional extended Penson-Kolb-Hubbard model

Science.gov (United States)

Ding, Hanqin; Ma, Xiaojuan; Zhang, Jun

2017-09-01

The experimental advances in cold fermion gases motivates the investigation of a one-dimensional (1D) correlated electronic system by incorporating a four-body coupling. Using the low-energy field theory scheme and focusing on the weak-coupling regime, we extend the 1D Penson-Kolb-Hubbard (PKH) model at half filling. It is found that the additional four-body interaction may significantly modify the quantum phase diagram, favoring the presence of the superconducting phase even in the case of two-body repulsions.

Application of Contrast Echocardiography in Invasive Cardiology

Directory of Open Access Journals (Sweden)

Mustafa Bulut

2010-12-01

Full Text Available Contrast echocardiography by rendering better imaging of the borders of cardiac chambers is a useful tool for evaluating cardiac function, mass, myocardial vascularization, microvascular structure (small vessel vasculature and viability. Contrast was first started to be used for patients with suboptimal image quality. It can be used in detecting defects in myocardial blood supply in patients with chest pain and determining the success of interventionalprocedures. It can also be of help in demonstrating myocardial viability after reperfusion treatment in patients who had myocardial infarction. It is expected to be used more widely in invasive cardiology for decision making, guiding and determining the success of the procedures. Advances in imaging techniques , development of contrast materials for evaluation of left system, contrast echocardiography may become a routine clinical practice.

Dressed-state analysis of efficient two-dimensional atom localization in a four-level atomic system

International Nuclear Information System (INIS)

Wang, Zhiping; Yu, Benli

2014-01-01

We investigate two-dimensional atom localization via spontaneous emission in a four-level atomic system. It is found that the detection probability and precision of two-dimensional atom localization can be significantly improved due to the interference effect between the spontaneous decay channels and the dynamically induced quantum interference generated by the probe and composite fields. More importantly, a 100% probability of finding an atom within the sub-half-wavelength domain of the standing waves can be reached when the corresponding conditions are satisfied. As a result, our scheme may be helpful in laser cooling or atom nano-lithography via atom localization. (paper)

Incremental value of contrast echocardiography in the evaluation of a cardiac thrombus.

Science.gov (United States)

Po, Jose Ricardo F; Tong, Matthew S; Grove, Erica L; Biederman, Robert W W

2017-02-01

A 52-year-old man presented with altered mental status and report of prior complaint of chest pain. On electrocardiography, anterolateral ST-segment elevations with Q-waves in the septal leads were seen. Initial echocardiography images demonstrated a thickened anteroseptum. Further imaging showed the presence of a well-attached laminated apical thrombus. Contrast echocardiography images showed that the thrombus had minimal attachment to the endocardial surface. CT head subsequently showed the presence of acute stroke. The case demonstrates the additional value of contrast echocardiography in the evaluation of cardiac masses despite the certainty in the diagnosis of a thrombus. © 2017, Wiley Periodicals, Inc.

Effects of Minimum and Maximum Doses of Furosemide on Fractional Shortening Parameter in Echocardiography of the New Zealand White Rabbit

Directory of Open Access Journals (Sweden)

Roham Vali, Mohammad Nasrollahzadeh Masouleh* and Siamak Mashhady Rafie1

2013-04-01

Full Text Available There is no data on the effect of maximum and minimum doses of furosemide on heart's work performance and amount of fractional shortening (FS in echocardiography of rabbit. This study was designed to validate probability of the mentionable effect. Twenty-four healthy female New Zealand white rabbits were divided into four equal groups. Maximum and minimum doses of furosemide were used for the first and second groups and the injection solution for the third and fourth groups was sodium chloride 0.9% which had the same calculated volumes of furosemide for the first two groups, respectively. The left ventricle FS in statutory times (0, 2, 5, 15, 30 minutes was determined by echocardiography. Measurements of Mean±SD, maximum and minimum amounts for FS values in all groups before injection and in statutory times were calculated. Statistical analysis revealed non-significant correlation between the means of FS. The results of this study showed that furosemide can be used as a diuretic agent for preparing a window approach in abdominal ultrasonography examination with no harmful effect on cardiac function.

Four-dimensional image display for associated particle imaging

International Nuclear Information System (INIS)

Headley, G.; Beyerle, A.; Durkee, R.; Hurley, P.; Tunnell, L.

1994-01-01

Associated particle imaging (API) is a three-dimensional neutron gamma imaging technique which provides both spatial and spectral information about an unknown. A local area network consisting of a UNIX fileserver and multiple DOS workstations has been chosen to perform the data acquisition and display functions. The data are acquired with a CAMAC system, stored in list mode, and sorted on the fileserver for display on the DOS workstations. Three of the display PCs, interacting with the fileserver, provide coordinated views as the operator ''slices'' the image. The operator has a choice of: a one-dimensional shadowgram from any side, two-dimensional shadowgrams from any side; a three-dimensional view (either perspective projection or stereoscopic). A common color scheme is used to carry energy information into the spatial images. ((orig.))

Audit of cardiac pathology detection using a criteria-based perioperative echocardiography service.

Science.gov (United States)

Faris, J G; Hartley, K; Fuller, C M; Langston, R B; Royse, C F; Veltman, M G

2012-07-01

Transthoracic echocardiography is often used to screen patients prior to non-cardiac surgery to detect conditions associated with perioperative haemodynamic compromise and to stratify risk. However, anaesthetists' use of echocardiography is quite variable. A consortium led by the American College of Cardiology Foundation has developed appropriate use criteria for echocardiography. At Joondalup Hospital in Western Australia, we have used these criteria to order echocardiographic studies in patients attending our anaesthetic pre-admission clinic. We undertook this audit to determine the incidence of significant echocardiographic findings using this approach. In a 22-month period, 606 transthoracic echocardiographic studies were performed. This represented 8.7% of clinic attendees and 1.7% of all surgical patients. In about two-thirds of the patients, the indication for echocardiography was identified on the basis of a telephone screening questionnaire. The most common indications were poor exercise tolerance (27.4%), ischaemic heart disease (20.9%) and cardiac murmurs (16.3%). Over 26% of patients studied had significant cardiac pathology (i.e. moderate or severe echocardiographic findings), most importantly moderate or severe aortic stenosis (8.6%), poor left ventricular function (7.1%), a regional wall motion abnormality (4.3%) or moderate or severe mitral regurgitation (4.1%). Using appropriate use criteria to guide ordering transthoracic echocardiography studies led to a high detection rate of clinically important cardiac pathology in our perioperative service.

Two-dimensional atom localization via probe absorption in a four-level atomic system

International Nuclear Information System (INIS)

Wang Zhi-Ping; Ge Qiang; Ruan Yu-Hua; Yu Ben-Li

2013-01-01

We have investigated the two-dimensional (2D) atom localization via probe absorption in a coherently driven four-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of 2D atom localization can be significantly improved via adjusting the system parameters. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization

Intra-cardiac echocardiography in alcohol septal ablation

DEFF Research Database (Denmark)

Cooper, Robert M; Shahzad, Adeel; Newton, James

2015-01-01

Alcohol septal ablation (ASA) in hypertrophic obstructive cardiomyopathy reduces left ventricular outflow tract gradients. A third of patients do not respond; inaccurate localisation of the iatrogenic infarct can be responsible. Transthoracic echocardiography (TTE) using myocardial contrast can...

Solitons in four dimensional gravity

International Nuclear Information System (INIS)

Matos, T.

1990-01-01

An alternative method to solve the Chiral equations with SL (2,R) symmetry is developed. One gets the N-soliton solution using the Neugebauer Ansatz. For N = 1 one obtains the Backlund transformation of the Chiral equations. From the application of this transformation for the flat seed solution one finds the Kerr-NUT solution. This method can be applied to generate solutions of the n-dimensional Einstein equations (Author)

Quasinormal modes of four-dimensional topological nonlinear charged Lifshitz black holes

Energy Technology Data Exchange (ETDEWEB)

Becar, Ramon [Universidad Cato lica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)

2016-02-15

We study scalar perturbations of four- dimensional topological nonlinear charged Lifshitz black holes with spherical and plane transverse sections, and we find numerically the quasinormal modes for scalar fields. Then we study the stability of these black holes under massive and massless scalar field perturbations. We focus our study on the dependence of the dynamical exponent, the nonlinear exponent, the angular momentum, and the mass of the scalar field in the modes. It is found that the modes are overdamped, depending strongly on the dynamical exponent and the angular momentum of the scalar field for a spherical transverse section. In contrast, for plane transverse sections the modes are always overdamped. (orig.)

Four-dimensional imaging of the initial stage of fast evolving plasmas

International Nuclear Information System (INIS)

Zhu Pengfei; Wang Weimin; Zhang Zhongchao; Chen Long; Zheng Jun; Li Runze; Qian Dong; Li Junjie; Wang Xuan; Cao Jianming; Sheng Zhengming; Zhang Jie

2010-01-01

Using an ultrafast electron probe capable of four-dimensional diagnosis, the initial stage of fast evolving plasmas produced by a 10 14 W/cm 2 laser irradiation of a metal target was investigated in real time with picosecond time resolution. The associated strong transient electric field was identified to have two components, which either focus or defocus the probe electron beam. The effects of this field on the probe electron beam can be reproduced by a self-expanding charge cloud containing about 5x10 7 suprathermal electrons with the outermost layer expanding at an average speed of 1.2x10 7 m/s.

Hand-carried ultrasound performed at bedside in cardiology inpatient setting – a comparative study with comprehensive echocardiography

Directory of Open Access Journals (Sweden)

Ramires Jose F

2004-11-01

Full Text Available Abstract Background Hand-carried ultrasound (HCU devices have been demonstrated to improve the diagnosis of cardiac diseases over physical examination, and have the potential to broaden the versatility in ultrasound application. The role of these devices in the assessment of hospitalized patients is not completely established. In this study we sought to perform a direct comparison between bedside evaluation using HCU and comprehensive echocardiography (CE, in cardiology inpatient setting. Methods We studied 44 consecutive patients (mean age 54 ± 18 years, 25 men who underwent bedside echocardiography using HCU and CE. HCU was performed by a cardiologist with level-2 training in the performance and interpretation of echocardiography, using two-dimensional imaging, color Doppler, and simple calliper measurements. CE was performed by an experienced echocardiographer (level-3 training and considered as the gold standard. Results There were no significant differences in cardiac chamber dimensions and left ventricular ejection fraction determined by the two techniques. The agreement between HCU and CE for the detection of segmental wall motion abnormalities was 83% (Kappa = 0.58. There was good agreement for detecting significant mitral valve regurgitation (Kappa = 0.85, aortic regurgitation (kappa = 0.89, and tricuspid regurgitation (Kappa = 0.74. A complete evaluation of patients with stenotic and prosthetic dysfunctional valves, as well as pulmonary hypertension, was not possible using HCU due to its technical limitations in determining hemodynamic parameters. Conclusion Bedside evaluation using HCU is helpful for assessing cardiac chamber dimensions, left ventricular global and segmental function, and significant valvular regurgitation. However, it has limitations regarding hemodynamic assessment, an important issue in the cardiology inpatient setting.

Semiautomated four-dimensional computed tomography segmentation using deformable models

International Nuclear Information System (INIS)

Ragan, Dustin; Starkschall, George; McNutt, Todd; Kaus, Michael; Guerrero, Thomas; Stevens, Craig W.

2005-01-01

The purpose of this work is to demonstrate a proof of feasibility of the application of a commercial prototype deformable model algorithm to the problem of delineation of anatomic structures on four-dimensional (4D) computed tomography (CT) image data sets. We acquired a 4D CT image data set of a patient's thorax that consisted of three-dimensional (3D) image data sets from eight phases in the respiratory cycle. The contours of the right and left lungs, cord, heart, and esophagus were manually delineated on the end inspiration data set. An interactive deformable model algorithm, originally intended for deforming an atlas-based model surface to a 3D CT image data set, was applied in an automated fashion. Triangulations based on the contours generated on each phase were deformed to the CT data set on the succeeding phase to generate the contours on that phase. Deformation was propagated through the eight phases, and the contours obtained on the end inspiration data set were compared with the original manually delineated contours. Structures defined by high-density gradients, such as lungs, cord, and heart, were accurately reproduced, except in regions where other gradient boundaries may have confused the algorithm, such as near bronchi. The algorithm failed to accurately contour the esophagus, a soft-tissue structure completely surrounded by tissue of similar density, without manual interaction. This technique has the potential to facilitate contour delineation in 4D CT image data sets; and future evolution of the software is expected to improve the process

Echocardiography for patent ductus arteriosus including closure in adults.

Science.gov (United States)

Chugh, Reema; Salem, Morris M

2015-01-01

Patent ductus arteriosus (PDA) represents at least 5-10% of all congenital heart defects (CHDs) making it a very important commonly diagnosed lesion. Although spontaneous closure of the PDA occurs within 24 to 48 hours after birth in the majority, those children who do not have natural or surgical closure may have a persistent PDA into adulthood. The diagnosis is most often confirmed by echocardiography that also guides catheter-based interventions and surgeries. Echocardiography continues to be the most important tool in long-term follow-up of residua and sequelae. © 2014, Wiley Periodicals, Inc.

Post-Newtonian approximation of the maximum four-dimensional Yang-Mills gauge theory

International Nuclear Information System (INIS)

Smalley, L.L.

1982-01-01

We have calculated the post-Newtonian approximation of the maximum four-dimensional Yang-Mills theory proposed by Hsu. The theory contains torsion; however, torsion is not active at the level of the post-Newtonian approximation of the metric. Depending on the nature of the approximation, we obtain the general-relativistic values for the classical Robertson parameters (γ = β = 1), but deviations for the Nordtvedt effect and violations of post-Newtonian conservation laws. We conclude that in its present form the theory is not a viable theory of gravitation

Does point-of-care functional echocardiography enhance cardiovascular care in the NICU?

Science.gov (United States)

Sehgal, A; McNamara, P J

2008-11-01

Although the last two decades have seen major advances in the care of sick, extremely premature newborns, the approach to cardiovascular assessment and monitoring remains suboptimal owing to an overreliance on poorly predictive clinical markers such as heart rate or capillary refill time. Point-of-care functional echocardiography (PCFecho) enables real-time evaluation of cardiac performance and systemic hemodynamics to characterize acute physiology, identify the exact nature of cardiovascular compromise and guide therapeutic decisions. In this article, we will review four clinical scenarios where bedside functional cardiac imaging enabled delineation of the real clinical problem and refinement of the therapeutic care plan with direct patient benefits.

Three-dimensional technology for linear morphological studies: a re-examination of cranial variation in four southern African indigenous populations.

Science.gov (United States)

Franklin, D; Freedman, L; Milne, N

2005-01-01

In order to compare linear dimensions made by traditional anthropometric techniques, and those obtained from three-dimensional coordinates, samples of four indigenous southern African populations were analysed. Linear measurements were obtained using mathematically transformed, three-dimensional landmark data on 207 male crania of Cape Nguni, Natal Nguni, Sotho and Shangaan. Univariate comparisons for accuracy of the transformed linear data were made with those in a traditional linear study by de Villiers (The Skull of the South African Negro: A Biometrical and Morphological Study. Witwatersrand University Press, Johannesburg) on similar samples and equivalent landmarks. Comparisons were not made with her Penrose (Ann Eugenics 18 (1954) 337) analysis as an apparently anomalous 'shape'-'size' statistic was found. The univariate comparisons demonstrated that accurate linear measurements could be derived from three-dimensional data, showing that it is possible to simultaneously obtain data for three-dimensional geometric 'shape' and linear interlandmark analyses. Using Penrose and canonical variates analyses of the transformed three-dimensional interlandmark measurements, similar population distances were found for the four indigenous southern African populations. The inter-population distance relationships took the form of three separated pairs of distances, with the within-pair distances very similar in size. The cranial features of the four populations were found to be overall very similar morphometrically. However the populations were each shown by CVA to have population specific features, and using discriminant analyses 50% or more of the individual crania (with the exception of the Sotho) could be referred to their correct populations.

Estimation of four-dimensional dose distribution using electronic portal imaging device in radiation therapy

International Nuclear Information System (INIS)

Mizoguchi, Asumi; Arimura, Hidetaka; Shioyama, Yoshiyuki

2013-01-01

We are developing a method to evaluate four-dimensional radiation dose distribution in a patient body based upon the animated image of EPID (electronic portal imaging device) which is an image of beam-direction at the irradiation. In the first place, we have obtained the image of the dose which is emitted from patient body at therapy planning using therapy planning CT image and dose evaluation algorism. In the second place, we have estimated the emission dose image at the irradiation using EPID animated image which is obtained at the irradiation. In the third place, we have got an affine transformation matrix including respiratory movement in the body by performing linear registration on the emission dose image at therapy planning to get the one at the irradiation. In the fourth place, we have applied the affine transformation matrix on the therapy planning CT image and estimated the CT image 'at irradiation'. Finally we have evaluated four-dimensional dose distribution by calculating dose distribution in the CT image 'at irradiation' which has been estimated for each frame of the EPID animated-image. This scheme may be useful for evaluating therapy results and risk management. (author)

Assessment of left ventricular wall motion and function by cross-sectional echocardiography

International Nuclear Information System (INIS)

Ono, Akifumi; Hirata, Shunkichi; Ishikawa, Kyozo

1982-01-01

The clinical efficacy of cross-sectional echocardiography (CSE) was evaluated with M-mode echocardiography and radionuclide cardioangiography (RCG) in 50 cases including 30 patients with myocardial infarction. Segmental wall motion by CSE was highly correlated with segmental wall motion and left ventricular ejection fraction by RCG (r = 0.89 in the former, r = -0.84 in the latter). On the other hand, the left ventricular ejection fraction by M-mode echocardiography revealed a fairly well correlation with that by RCG ( r = 0.68). These results suggest that, as compared with RCG, CSE is quite useful in an evaluation of left ventricular function and in a detection of segmental wall motion abnormalities. (author)

All the Four-Dimensional Static, Spherically Symmetric Solutions of Abelian Kaluza-Klein Theory

International Nuclear Information System (INIS)

Cvetic, M.; Youm, D.

1995-01-01

We present the explicit form for all the four-dimensional, static, spherically symmetric solutions in (4+n)-d Abelian Kaluza-Klein theory by performing a subset of SO(2,n) transformations corresponding to four SO(1,1) boosts on the Schwarzschild solution, supplemented by SO(n)/SO(n-2) transformations. The solutions are parametrized by the mass M, Taub-NUT charge a, and n electric rvec Q and n magnetic rvec P charges. Nonextreme black holes (with zero Taub-NUT charge) have either the Reissner-Nordstroem or Schwarzschild global space-time. Supersymmetric extreme black holes have a null or naked singularity, while nonsupersymmetric extreme ones have a global space-time of extreme Reissner-Nordstroem black holes. copyright 1995 The American Physical Society

Gated blood pool tomography for the evaluation of global and regional left ventricular function in comparison to planar techniques and echocardiography.

Science.gov (United States)

Canclini, S; Terzi, A; Rossini, P; Vignati, A; La Canna, G; Magri, G C; Pizzocaro, C; Giubbini, R

2001-01-01

Multigated radionuclide ventriculography (MUGA) is a simple and reliable tool for the assessment of global systolic and diastolic function and in several studies it is still considered a standard for the assessment of left ventricular ejection fraction. However the evaluation of regional wall motion by MUGA is critical due to two-dimensional imaging and its clinical use is progressively declining in favor of echocardiography. Tomographic MUGA (T-MUGA) is not widely adopted in clinical practice. The aim of this study was to compare T-MUGA to planar MUGA (P-MUGA) for the assessment of global ejection fraction and to transthoracic echocardiography for the evaluation of regional wall motion. A 16-segment model was adopted for the comparison with echo regional wall motion. For each one of the 16 segments the normal range of T-MUGA ejection fraction was quantified and a normal data file was defined; the average value -2.5 SD was used as the lower threshold to identify abnormal segments. In addition, amplitude images from Fourier analysis were quantified and considered abnormal according to three different thresholds (25, 50 and 75% of the maximum). In a study group of 33 consecutive patients the ejection fraction values of T-MUGA highly correlated with those of P-MUGA (r = 0.93). The regional ejection fraction (according to the normal database) and the amplitude analysis (50% threshold) allowed for the correct identification of 203/226 and 167/226 asynergic segments by echocardiography, and of 269/302 and 244/302 normal segments, respectively. Therefore sensitivity, specificity and overall accuracy to detect regional wall motion abnormalities were 90, 89, 89% and 74, 81, 79% for regional ejection fraction and amplitude analysis, respectively. T-MUGA is a reliable tool for regional wall motion evaluation, well correlated with echocardiography, less subjective and able to provide quantitative data.

False vacuum decay in quantum mechanics and four dimensional scalar field theory

Science.gov (United States)

Bezuglov, Maxim

2018-04-01

When the Higgs boson was discovered in 2012 it was realized that electroweak vacuum may suffer a possible metastability on the Planck scale and can eventually decay. To understand this problem it is important to have reliable predictions for the vacuum decay rate within the framework of quantum field theory. For now, it can only be done at one loop level, which is apparently is not enough. The aim of this work is to develop a technique for the calculation of two and higher order radiative corrections to the false vacuum decay rate in the framework of four dimensional scalar quantum field theory and then apply it to the case of the Standard Model. To achieve this goal, we first start from the case of d=1 dimensional QFT i.e. quantum mechanics. We show that for some potentials two and three loop corrections can be very important and must be taken into account. Next, we use quantum mechanical example as a template for the general d=4 dimensional theory. In it we are concentrating on the calculations of bounce solution and corresponding Green function in so called thin wall approximation. The obtained Green function is then used as a main ingredient for the calculation of two loop radiative corrections to the false vacuum decay rate.

Transmission of supersymmetry breaking from a four-dimensional boundary

International Nuclear Information System (INIS)

Mirabelli, E.A.; Peskin, M.E.

1998-01-01

In the strong-coupling limit of the heterotic string theory constructed by Horava and Witten, an 11-dimensional supergravity theory is coupled to matter multiplets confined to 10-dimensional mirror planes. This structure suggests that realistic unification models are obtained, after compactification of 6 dimensions, as theories of 5-dimensional supergravity in an interval, coupling to matter fields on 4-dimensional walls. Supersymmetry breaking may be communicated from one boundary to another by the 5-dimensional fields. In this paper, we study a toy model of this communication in which 5-dimensional super-Yang-Mills theory in the bulk couples to chiral multiplets on the walls. Using the auxiliary fields of the Yang-Mills multiplet, we find a simple algorithm for coupling the bulk and boundary fields. We demonstrate two different mechanisms for generating soft supersymmetry breaking terms in the boundary theory. We also compute the Casimir energy generated by supersymmetry breaking. copyright 1998 The American Physical Society

Hemodynamic measurement using four-dimensional phase-contrast MRI: Quantification of hemodynamic parameters and clinical applications

Energy Technology Data Exchange (ETDEWEB)

Ha, Ho Jin; Lee, Sang Joon [POSTECH Biotech Center, Pohang University of Science and Technology, Pohang (Korea, Republic of); Kim, Guk Bae; Kweon, Ji Hoon; Kim, Young Hak; Lee, Deok Hee; Yang, Dong Hyun; KIm, Nam Kug [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2016-07-15

Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions.

Hemodynamic Measurement Using Four-Dimensional Phase-Contrast MRI: Quantification of Hemodynamic Parameters and Clinical Applications

Energy Technology Data Exchange (ETDEWEB)

Ha, Hojin [POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Kim, Guk Bae [Asan Institute of Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Kweon, Jihoon [Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Lee, Sang Joon [POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Kim, Young-Hak [Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Lee, Deok Hee; Yang, Dong Hyun [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Kim, Namkug [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of)

2016-11-01

Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions.

Comparison of exercise stress testing with dobutamine stress echocardiography and radionuclide ventriculography for diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Ozdemir, K.; Kisacik, H.L.; Oguzhan, A.

1999-01-01

Dobutamine stress echocardiography, Tc-99m radionuclide ventriculography (RNVG), and exercise stress testing were performed prospectively in 63 patients with suspected coronary artery disease to compare the values of exercise testing, dobutamine stress echocardiography and RNVG in the non-invasive diagnosis of coronary artery disease. The sensitivities of dobutamine stress echocardiography and RNVG were found to be higher than that of exercise testing (93-62%, p 0.05). There were no differences between the sensitivities of the three techniques in multiple vessel disease (p>0.05). The specificities of dobutamine stress echocardiography and RNVG were higher than that of exercise testing (for both of the tests 86-62%, p 0.05). The results of dobutamine stress echocardiography RNVG were concordant with each other in 46 patients (76%, kappa=65%) in sectional analysis. Dobutamine stress echocardiography and RNVG tests were comparable with each other in 85% of the 189 segments (kappa=64%). The expected 5% decrease at peak doses of dobutamine was not detected in stress echocardiography in 25 patients and in RNVG in 26 of the patients. Dobutamine stress echocardiography and RNVG are superior to exercise testing in the diagnosis of single vessel disease and there is no significant difference between the two techniques. When the ejection fraction is considered in dobutamine stress echocardiography and RNVG, it does not make an additional contribution to the diagnosis of coronary artery disease. (author)

The Interplay between Fasting Glucose, Echocardiography, and Biomarkers

DEFF Research Database (Denmark)

Pareek, Manan

preventive setting, remains incomplete. Phenotypical heterogeneity may be even greater among subjects with hyperglycemic conditions, i.e., prediabetes and diabetes, which is worrisome, given the dramatic global rise in mean fasting glucose levels, and the strong association with adverse cardiovascular...... subclinical changes to manifest disease include echocardiography and circulating biomarkers. Objectives 1) To examine whether greater fasting plasma glucose (FPG) levels were associated with left ventricular mass (LVM), geometric pattern, diastolic function, and concentrations of N-terminal prohormone...... from the three categories defined by baseline FPG, i.e., normal fasting glucose, impaired fasting glucose, and diabetes, including use of anti-diabetic medication. Blood samples for cardiovascular biomarker assessments were drawn at the time of echocardiography and kept frozen until analysis. Outcome...

Contrast agents provide a faster learning curve in dipyridamole stress echocardiography.

Science.gov (United States)

Zamorano, Jose; Sánchez, Violeta; Moreno, Raúl; Almería, Carlos; Rodrigo, Jose; Serra, Viviana; Azcona, Luis; Aubele, Adalia; Mataix, Luis; Sánchez-Harguindey, Luis

2002-12-01

Interobserver variability is an important limitation of the stress echocardiography and depends on the echocardiographer training. Our aim was to evaluate if the use of contrast agents during dipyridamole stress echocardiography would improve the agreement between an experienced and a non-experienced observer in stress echo and therefore if contrast would affect the learning period of dypyridamole stress echo. Two independent observers without knowledge of any patient data interpreted all stress studies. One observer was an experienced one and the other had experience in echocardiography but not in stress echo. Two observers analysed 87 non-selected and consecutive studies. Out of the 87 studies, 46 were performed without contrast administration, whereas i.v. contrast (2.5 g Levovist by two bolus at rest and at peak stress) was administered in 41. In all cases, second harmonic imaging and stress digitalisation pack was used. The agreement between observers showed a kappa index of 0.58 and 0.83 without and with contrast administration, respectively. The use of contrast agents provides a better agreement in the evaluation of stress echo between an experienced and a non-experienced observer in stress echo. Adding routinely contrast agents could probably reduce the number of exams required for the necessary learning curve in stress echocardiography.

Portopulmonary hypertension: Improved detection using CT and echocardiography in combination

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Devaraj, Anand [Royal Brompton and Harefield NHS Foundation Trust, Department of Radiology, London (United Kingdom); Loveridge, Robert; Bernal, William; Willars, Christopher; Wendon, Julia A.; Auzinger, Georg [King' s College Hospital NHS Foundation Trust, The Institute of Liver Studies, King' s Health Partners, King' s College London, London (United Kingdom); Bosanac, Diana; Stefanidis, Konstantinos; Desai, Sujal R. [King' s College Hospital NHS Foundation Trust, Department of Radiology, King' s Health Partners, King' s College London, London (United Kingdom)

2014-10-15

To establish the relationship between CT signs of pulmonary hypertension and mean pulmonary artery pressure (mPAP) in patients with liver disease, and to determine the additive value of CT in the detection of portopulmonary hypertension in combination with transthoracic echocardiography. Forty-nine patients referred for liver transplantation were retrospectively reviewed. Measured CT signs included the main pulmonary artery/ascending aorta diameter ratio (PA/AA{sub meas}) and the mean left and right main PA diameter (RLPA{sub meas}). Enlargement of the pulmonary artery compared to the ascending aorta was also assessed visually (PA/AA{sub vis}). CT measurements were correlated with right-sided heart catheter-derived mPAP. The ability of PA/AA{sub vis} combined with echocardiogram-derived right ventricular systolic pressure (RVSP) to detect portopulmonary hypertension was tested with ROC analysis. There were moderate correlations between mPAP and both PA/AA{sub meas} and RLPA{sub meas} (r{sub s} = 0.41 and r{sub s} = 0.42, respectively; p < 0.005). Compared to transthoracic echocardiography alone (AUC = 0.59, p = 0.23), a diagnostic algorithm incorporating PA/AA{sub vis} and transthoracic echocardiography-derived RVSP improved the detection of portopulmonary hypertension (AUC = 0.8, p < 0.0001). CT contributes to the non-invasive detection of portopulmonary hypertension when used in a diagnostic algorithm with transthoracic echocardiography. CT may have a role in the pre-liver transplantation triage of patients with portopulmonary hypertension for right-sided heart catheterisation. (orig.)

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism.

Science.gov (United States)

Saric, Muhamed; Armour, Alicia C; Arnaout, M Samir; Chaudhry, Farooq A; Grimm, Richard A; Kronzon, Itzhak; Landeck, Bruce F; Maganti, Kameswari; Michelena, Hector I; Tolstrup, Kirsten

2016-01-01

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Acute right ventricular dysfunction: real-time management with echocardiography.

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Krishnan, Sundar; Schmidt, Gregory A

2015-03-01

In critically ill patients, the right ventricle is susceptible to dysfunction due to increased afterload, decreased contractility, or alterations in preload. With the increased use of point-of-care ultrasonography and a decline in the use of pulmonary artery catheters, echocardiography can be the ideal tool for evaluation and to guide hemodynamic and respiratory therapy. We review the epidemiology of right ventricular failure in critically ill patients; echocardiographic parameters for evaluating the right ventricle; and the impact of mechanical ventilation, fluid therapy, and vasoactive infusions on the right ventricle. Finally, we summarize the principles of management in the context of right ventricular dysfunction and provide recommendations for echocardiography-guided management.

Student tutors for hands-on training in focused emergency echocardiography – a randomized controlled trial

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Kühl Matthias

2012-10-01

Full Text Available Abstract Background Focused emergency echocardiography performed by non-cardiologists has been shown to be feasible and effective in emergency situations. During resuscitation a short focused emergency echocardiography has been shown to narrow down potential differential diagnoses and to improve patient survival. Quite a large proportion of physicians are eligible to learn focused emergency echocardiography. Training in focused emergency echocardiography usually comprises a lecture, hands-on trainings in very small groups, and a practice phase. There is a shortage of experienced echocardiographers who can supervise the second step, the hands-on training. We thus investigated whether student tutors can perform the hands-on training for focused emergency echocardiography. Methods A total of 30 volunteer 4th and 5th year students were randomly assigned to a twelve-hour basic echocardiography course comprising a lecture followed by a hands-on training in small groups taught either by an expert cardiographer (EC or by a student tutor (ST. Using a pre-post-design, the students were evaluated by an OSCE. The students had to generate two still frames with the apical five-chamber view and the parasternal long axis in five minutes and to correctly mark twelve anatomical cardiac structures. Two blinded expert cardiographers rated the students’ performance using a standardized checklist. Students could achieve a maximum of 25 points. Results Both groups showed significant improvement after the training (p Conclusions Hands-on training by student tutors led to a significant gain in echocardiography skills, although inferior to teaching by an expert cardiographer.

Application of Real-Time Three-Dimensional Echocardiography to Evaluate the Pre- and Postoperative Right Ventricular Systolic Function of Patients with Tetralogy of Fallot

Science.gov (United States)

Cui, Cunying; Liu, Lin; Fan, Taibing; Peng, Bangtian; Cheng, Zhaoyun; Ge, Zhenwei; Li, Yanan; Liu, Yuanyuan; Zhang, Yanwei; Ai, Feng; Zhang, Lianzhong

2015-01-01

Tetralogy of Fallot (ToF) can be challenging for clinicians to both diagnose and treat, given the multiple heart defects that are by definition associated with the illness. This study investigates the value of real-time three- dimensional echocardiography (RT-3DE) in evaluating the pre-and postoperative right ventricular systolic function of patients with tetralogy of Fallot. A total of 41 ToF patients were divided into two groups: the child group (CG) and the adult group (AG) according to age. The right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and the right ventricular ejection fraction (RVEF) of ToF patients were measured before surgery, 7 days, and 3 months after the surgery. The correlation between the preoperative Nakata index and RVEF was then analyzed. Compared with the RVEDV and RVESV prior to surgery, those of the postoperative 7-day and 3-month were not statistically significant (p > 0.05). However, RVEF decreased, and the difference was statistically significant (p 0.05). Compared with the pre-and postoperative RVEDV and RVESV of CG, those of AG increased. However, RVEF decreased, and the differences were statistically significant (p < 0.05). Our study indicated that the correlation between preoperative Nakata index and RVEF was good. Ultimately, we did confirm that RT-3DE can quantitatively evaluate the right ventricular volume and systolic function of ToF patients, thereby providing clinical significance in determining postoperative efficacy and prognosis evaluation. PMID:27122891

Nonperturbative construction of nonrenormalizable models of quantum field theory in four-dimensional space-time

International Nuclear Information System (INIS)

Raczka, R.

1979-01-01

Construction of non-cutoff Euclidean Green's functions for nonrenormalizable interactions Lsub(I)(phi)=lambda∫dσ(epsilon):expepsilonphi: in four-dimensional space-time is presented. It is shown that all axioms for the generating functional of E.G.F. are satisfied except perhaps the SO(4) invariance. It is shown that the singularities of E.G.F. for coinciding points are not worse than those of the free theory. (author)

Early Impairment of Cardiac Function and Asynchronization of Systemic Amyloidosis with Preserved Ejection Fraction Using Two-Dimensional Speckle Tracking Echocardiography.

Science.gov (United States)

Huang, He; Jing, Xian-chao; Hu, Zhang-xue; Chen, Xi; Liu, Xiao-qin

2015-12-01

To observe the ventricular global and regional function of the patients with systemic amyloidosis using two-dimensional speckle tracking echocardiography. The study enrolled 31 consecutive biopsy-proved patients with systemic amyloidosis who underwent echocardiographic examination and EF ≥ 55% and 37 age- and gender-matched healthy controls. We compared systolic strain and strain rate, diastolic strain rate, time to peak strain, peak delay time in longitudinal, radial, circumferential directions in 16 left ventricular segments. The global peak systolic longitudinal and radial strain of left ventricle, peak systolic longitudinal strain and strain rate, diastolic strain rate of right ventricular free wall were also compared. (1) Global peak systolic longitudinal strain (GPSLS), peak systolic longitudinal strain (PSLS) and strain rate (PSLSR), peak early diastolic longitudinal strain rate (PELSR) in 16 segments were decreased in case (P < 0.05). (2) Peak systolic radial strain and strain rate of inferoseptum and inferolateral at the level of papillary muscle were lower (P < 0.05), and peak early diastolic radial strain rate (PERSR) was reduced (P < 0.05). (3) Peak early diastolic circumferential strain rate was lower (P < 0.05). (4) Time to peak systolic longitudinal, radial, circumferential strain was longer, and peak delay time at the same level retarded (P < 0.05). (5) Into right ventricular wall, PSLS and PSLSR at mid-segment, and PSLSR, PELSR, peak atrial systolic longitudinal strain rate (PALSR) at basal were reduced (P < 0.05). (6) Inverse correlation between interventricular septum (IVS) thickness and GPSLS and GPSRS was found (P < 0.05). Systolic and diastolic dysfunction existed in systemic amyloidosis with preserved EF. Mechanical contraction disorder may be one reason for systolic dysfunction. GPLSR and GPRSR were negatively related to IVS thickness. © 2015, Wiley Periodicals, Inc.

Four-dimensional data coupled to alternating weighted residue constraint quadrilinear decomposition model applied to environmental analysis: Determination of polycyclic aromatic hydrocarbons

Science.gov (United States)

Liu, Tingting; Zhang, Ling; Wang, Shutao; Cui, Yaoyao; Wang, Yutian; Liu, Lingfei; Yang, Zhe

2018-03-01

Qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) was carried out by three-dimensional fluorescence spectroscopy combining with Alternating Weighted Residue Constraint Quadrilinear Decomposition (AWRCQLD). The experimental subjects were acenaphthene (ANA) and naphthalene (NAP). Firstly, in order to solve the redundant information of the three-dimensional fluorescence spectral data, the wavelet transform was used to compress data in preprocessing. Then, the four-dimensional data was constructed by using the excitation-emission fluorescence spectra of different concentration PAHs. The sample data was obtained from three solvents that are methanol, ethanol and Ultra-pure water. The four-dimensional spectral data was analyzed by AWRCQLD, then the recovery rate of PAHs was obtained from the three solvents and compared respectively. On one hand, the results showed that PAHs can be measured more accurately by the high-order data, and the recovery rate was higher. On the other hand, the results presented that AWRCQLD can better reflect the superiority of four-dimensional algorithm than the second-order calibration and other third-order calibration algorithms. The recovery rate of ANA was 96.5% 103.3% and the root mean square error of prediction was 0.04 μgL- 1. The recovery rate of NAP was 96.7% 115.7% and the root mean square error of prediction was 0.06 μgL- 1.

An investigation into the causes of unexpected intra-operative transoesophageal echocardiography findings.

Science.gov (United States)

Skinner, H J; Mahmoud, A; Uddin, A; Mathew, T

2012-04-01

There is uncertainty regarding echocardiography before cardiac surgery, especially with regard to timing and disease progression as well as potential errors. We investigated the causes of unexpected intra-operative transoesophageal echocardiography findings by performing a 33-month audit. We found that there were 50/797 (6%) unexpected findings that led to an alteration in surgical strategy in 34 (4%) patients. Of the unexpected findings, 25 (50%) were unrelated to pre-operative pathology. After reviewing pre-operative studies and reports, unexpected findings were found to be due to: reporting errors in 20 patients (44%); limitations in transthoracic compared to transoesophageal echocardiography in 14 patients (30%); disease progression in 10 patients (22%); and inter-observer variability in two patients (4%). We identified six reports out of 797 (0.8%) that contained potentially serious errors. Surgical management changed in 18/20 (90%) patients in whom the unexpected change was due to reporting error, compared to 16/30 (53%) patients whose pre-operative echocardiogram was correctly reported (p = 0.006). Our study suggests that pre-operative echocardiography reporting errors are common and important. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

The Role of Stress Echocardiography in Valvular Heart Disease: A Current Appraisal.

Science.gov (United States)

Gentry Iii, James L; Phelan, Dermot; Desai, Milind Y; Griffin, Brian P

Stress echocardiography is a widely available, safe, low-cost, versatile imaging modality which is becoming increasingly recognized as a valuable tool in the assessment of patients with native and prosthetic left-sided valvular heart disease. It provides a quantitative assessment to help guide clinical decision-making when discordance exists between symptoms and severity of valve disease. Exercise (treadmill or bicycle) remains the preferred stress modality, but pharmacological augmentation with dobutamine can be used if needed. Low-dose dobutamine stress echocardiography is specifically valuable in patients with low-flow, low-gradient aortic stenosis when attempting to differentiate true severe aortic stenosis from pseudo-severe aortic stenosis. Stress echocardiography not only identifies high-risk features that indicate need for earlier surgery, it also provides useful information for the peri- and postoperative period, including long-term outcome, risk stratification to guide monitoring frequency, and offers guidance for eligibility in competitive sports participation. As research continues to expand the utility of stress echocardiography in the management of patients with valvular heart disease, future research should focus on the recognition of newer parameters identifying high-risk features including subsequent validation in a large population. © 2017 S. Karger AG, Basel.

Mechanisms of valve competency after mitral valve annuloplasty for ischaemic mitral regurgitation using the Geoform ring: insights from three-dimensional echocardiography.

Science.gov (United States)

Armen, Todd A; Vandse, Rashmi; Crestanello, Juan A; Raman, Subha V; Bickle, Katherine M; Nathan, Nadia S

2009-01-01

Left ventricular remodelling leads to functional mitral regurgitation resulting from annular dilatation, leaflet tethering, tenting, and decreased leaflet coaptation. Mitral valve annuloplasty restores valve competency, improving the patient's functional status and ventricular function. This study was designed to evaluate the mechanisms underlying mitral valve competency after the implantation of a Geoform annuloplasty ring using three-dimensional (3D) echocardiography. Seven patients (mean age of 65 years) with ischaemic mitral regurgitation underwent mitral valve annuloplasty with the Geoform ring and coronary artery bypass surgery. Pre- and post-operative 3D echocardiograms were performed. Following mitral annuloplasty, mitral regurgitation decreased from 3.4+/-0.2 to 0.9+/-0.3 (P-value<0.0001), mitral valve tenting volume from 13+/-1.7 to 3.2+/-0.3 mL (P-value<0.001), annulus area from 12.6+/-1.0 to 3.3+/-0.2 cm2 (P-value<0.0001), valve circumference from 13+/-0.5 to 7.3+/-0.3 cm (P-value<0.0001), septolateral distance from 2.1+/-0.1 to 1.4+/-0.06 cm (P-value<0.01) and intercommissural distance from 3.4+/-0.1 to 2.7+/-0.03 cm (P-value<0.03). There was significant decrease in the septolateral distance at the level of A2-P2 with respect to other regions. These geometric changes were associated with the improvement in the NYHA class from 3.1+/-0.3 to 1.3+/-0.3 (P-value<0.002). The mitral valve annuloplasty with the Geoform ring restores leaflet coaptation and eliminates mitral regurgitation by effectively modifying the mitral annular geometry.

Results of a Prospective Echocardiography Trial in International Space Station Crew

Science.gov (United States)

Hamilton, Douglas R.; Sargsyan, Ashot E.; Martin, David; Garcia, Kathleen M.; Melton, Shannon; Feiverson, Alan; Dulchavsky, Scott A.

2009-01-01

In the framework of an operationally oriented investigation, we conducted a prospective trial of a standard clinical echocardiography protocol in a cohort of long-duration crewmembers. The resulting primary and processed data appear to have no precedents. Our tele-echocardiography paradigm, including just-in-time e-training methods, was also assessed. A critical review of the imaging technique, equipment and setting limitations, and quality assurance is provided, as well as the analysis of "space normal" data.

A Lifshitz black hole in four dimensional R2 gravity

International Nuclear Information System (INIS)

Cai Ronggen; Liu Yan; Sun Yawen

2009-01-01

We consider a higher derivative gravity theory in four dimensions with a negative cosmological constant and show that vacuum solutions of both Lifshitz type and Schroedinger type with arbitrary dynamical exponent z exist in this system. Then we find an analytic black hole solution which asymptotes to the vacuum Lifshitz solution with z = 3/2 at a specific value of the coupling constant. We analyze the thermodynamic behavior of this black hole and find that the black hole has zero entropy while non-zero temperature, which is very similar to the case of BTZ black holes in new massive gravity at a specific coupling. In addition, we find that the three dimensional Lifshitz black hole recently found by E. Ayon-Beato et al. has a negative entropy and mass when the Newton constant is taken to be positive.

Association of heart failure hospitalizations with combined electrocardiography and echocardiography criteria for left ventricular hypertrophy

DEFF Research Database (Denmark)

Gerdts, Eva; Okin, Peter M; Boman, Kurt

2012-01-01

The value of performing echocardiography in hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) is uncertain.......The value of performing echocardiography in hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) is uncertain....

Assessment of Myocardial Ischemia in Obese Individuals Undergoing Physical Stress Echocardiography (PSE

Directory of Open Access Journals (Sweden)

Mara Graziele Maciel Silveira

2015-05-01

Full Text Available Background: Physical stress echocardiography is an established methodology for diagnosis and risk stratification of coronary artery disease in patients with physical capacity. In obese (body mass index ≥ 30 kg/m2 the usefulness of pharmacological stress echocardiography has been demonstrated; however, has not been reported the use of physical stress echocardiography in this growing population group. Objective: To assess the frequency of myocardial ischemia in obese and non-obese patients undergoing physical stress echocardiography and compare their clinical and echocardiographic differences. Methods: 4,050 patients who underwent treadmill physical stress echocardiography were studied according to the Bruce protocol, divided into two groups: obese (n = 945; 23.3% and non-obese (n = 3,105; 76.6%. Results: There was no difference regarding gender. Obese patients were younger (55.4 ± 10.9 vs. 57.56 ± 11.67 and had a higher frequency of hypertension (75.2% vs. 57, 2%; p < 0.0001, diabetis mellitus (15.2% vs. 10.9%; p < 0.0001, dyslipidemia (59.5% vs 51.9%; p < 0.0001, family history of coronary artery disease (59.3% vs. 55.1%; p = 0.023 and physical inactivity (71.4% vs. 52.9%, p < 0.0001. The obese had greater aortic dimensions (3.27 vs. 3.14 cm; p < 0.0001, left atrium (3.97 vs. 3.72 cm; p < 0.0001 and the relative thickness of the ventricule (33.7 vs. 32.8 cm; p < 0.0001. Regarding the presence of myocardial ischemia, there was no difference between groups (19% vs. 17.9%; p = 0.41. In adjusted logistic regression, the presence of myocardial ischemia remained independently associated with age, female gender, diabetes and hypertension. Conclusion: Obesity did not behave as a predictor of the presence of ischemia and the physical stress echocardiography. The application of this assessment tool in large scale sample demonstrates the feasibility of the methodology, also in obese.

Comparison of aortic root dimensions and geometries before and after transcatheter aortic valve implantation by 2- and 3-dimensional transesophageal echocardiography and multislice computed tomography.

NARCIS (Netherlands)

Ng, A.C.; Delgado, V.; Kley, F. van der; Shanks, M.; Veire, N.R. van de; Bertini, M.; Nucifora, G.; Bommel, R.J. van; Tops, L.F.; Weger, A. de; Tavilla, G.; Roos, A. de; Kroft, L.J.; Leung, D.Y.; Schuijf, J.; Schalij, M.J.; Bax, J.J.

2010-01-01

BACKGROUND: 3D transesophageal echocardiography (TEE) may provide more accurate aortic annular and left ventricular outflow tract (LVOT) dimensions and geometries compared with 2D TEE. We assessed agreements between 2D and 3D TEE measurements with multislice computed tomography (MSCT) and changes in

Analysis of interfractional variations in pancreatic position based on four-dimensional computed tomography

International Nuclear Information System (INIS)

Shiinoki, Takehiro; Itoh, Akio; Shibuya, Keiko; Nakamura, Mitsuhiro; Nakamura, Akira; Matsuo, Yukinori; Sawada, Akira; Mizowaki, Takashi; Hiraoka, Masahiro

2010-01-01

The purpose of this study was to assess inter-fractional variations in pancreatic position using four-dimensional computed tomography (4D-CT) and to find the suitable phase of respiration for breath-holding. The variations in respiratory motion range during treatment course and inter-fractional variations in pancreatic positions were not negligible; however, our study suggested that breath-holding at end-exhalation with some coaching techniques might be considerable one of the non-invasive approaches to get higher positional reproducibility of pancreatic tumors. (author)

Avoiding transthoracic echocardiography and transesophageal echocardiography for patients with variable body mass indexes in infective endocarditis

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Robert Sogomonian

2016-04-01

Full Text Available Background: Echocardiography has been a popular modality used to aid in the diagnosis of infective endocarditis (IE with the modified Duke criteria. We evaluated the necessity between the uses of either a transthoracic echocardiography (TTE or transesophageal echocardiography (TEE in patients with a body mass index (BMI greater than or equal to 25 kg/m2 and less than 25 kg/m2. Methods: A single-centered, retrospective study of 198 patients between 2005 and 2012 diagnosed with IE based on modified Duke criteria. Patients, required to be above age 18, had undergone an echocardiogram study and had blood cultures to be included in the study. Results: Among 198 patients, two echocardiographic groups were evaluated as 158 patients obtained a TTE, 143 obtained a TEE, and 103 overlapped with TEE and TTE. Out of these patients, 167 patients were included in the study as 109 (65% were discovered to have native valve vegetations on TEE and 58 (35% with TTE. TTE findings were compared with TEE results for true negatives and positives to isolate valvular vegetations. Overall sensitivity of TTE was calculated to be 67% with a specificity of 93%. Patients were further divided into two groups with the first group having a BMI ≥25 kg/m2 and the subsequent group with a BMI <25 kg/m2. Patients with a BMI ≥25 kg/m2 who underwent a TTE study had a sensitivity and specificity of 54 and 92%, respectively. On the contrary, patients with a BMI < 25 kg/m2 had a TTE sensitivity and specificity of 78 and 95%, respectively. Conclusions: Patients with a BMI <25 kg/m2 and a negative TTE should refrain from further diagnostic studies, with TEE strong clinical judgment is warranted. Patients with a BMI ≥ 25 kg/m2 may proceed directly to TEE as the initial study, possibly avoiding an additional study with a TTE.

Structure of modes of smoothly irregular three-dimensional integrated optical four-layer waveguide

International Nuclear Information System (INIS)

Egorov, A.A.; Ajryan, Eh.A.; Sevast'yanov, A.L.; Sevast'yanov, L.A.

2009-01-01

As a method of research of an integrated optical multilayer waveguide, satisfying the condition of smooth modification of the shape of the studied three-dimensional structure, an asymptotic method is used. Three-dimensional fields of smoothly deforming modes of the integrated optical waveguide are circumscribed analytically. An evident dependence of the contributions of the first order of smallness in the amplitudes of the electrical and magnetic fields of the quasi-waveguide modes is obtained. The canonical type of the equations circumscribing propagation of quasi-TE and quasi-TM modes in the smoothly irregular part of a four-layer integrated optical waveguide is represented for an asymptotic method. With the help of the method of coupled waves and perturbation theory method, the shifts of complex propagation constants for quasi-TE and quasi-TM modes are obtained in an explicit form. The elaborated theory is applicable for the analysis of similar structures of dielectric, magnetic and metamaterials in a sufficiently broad band of electromagnetic wavelengths

Four-dimensional microscope- integrated optical coherence tomography to enhance visualization in glaucoma surgeries.

Science.gov (United States)

Pasricha, Neel Dave; Bhullar, Paramjit Kaur; Shieh, Christine; Viehland, Christian; Carrasco-Zevallos, Oscar Mijail; Keller, Brenton; Izatt, Joseph Adam; Toth, Cynthia Ann; Challa, Pratap; Kuo, Anthony Nanlin

2017-01-01

We report the first use of swept-source microscope-integrated optical coherence tomography (SS-MIOCT) capable of live four-dimensional (4D) (three-dimensional across time) imaging intraoperatively to directly visualize tube shunt placement and trabeculectomy surgeries in two patients with severe open-angle glaucoma and elevated intraocular pressure (IOP) that was not adequately managed by medical intervention or prior surgery. We performed tube shunt placement and trabeculectomy surgery and used SS-MIOCT to visualize and record surgical steps that benefitted from the enhanced visualization. In the case of tube shunt placement, SS-MIOCT successfully visualized the scleral tunneling, tube shunt positioning in the anterior chamber, and tube shunt suturing. For the trabeculectomy, SS-MIOCT successfully visualized the scleral flap creation, sclerotomy, and iridectomy. Postoperatively, both patients did well, with IOPs decreasing to the target goal. We found the benefit of SS-MIOCT was greatest in surgical steps requiring depth-based assessments. This technology has the potential to improve clinical outcomes.

Pericardial Effusion and Pericardiocentesis: Role of Echocardiography

Science.gov (United States)

2012-01-01

Pericardial effusion can develop from any pericardial disease, including pericarditis and several systemic disorders, such as malignancies, pulmonary tuberculosis, chronic renal failure, thyroid diseases, and autoimmune diseases. The causes of large pericardial effusion requiring invasive pericardiocentesis may vary according to the time, country, and hospital. Transthoracic echocardiography is the most important tool for diagnosis, grading, the pericardiocentesis procedure, and follow up of pericardial effusion. Cardiac tamponade is a kind of cardiogenic shock and medical emergency. Clinicians should understand the tamponade physiology, especially because it can develop without large pericardial effusion. In addition, clinicians should correlate the echocardiographic findings of tamponade, such as right ventricular collapse, right atrial collapse, and respiratory variation of mitral and tricuspid flow, with clinical signs of clinical tamponade, such as hypotension or pulsus paradoxus. Percutaneous pericardiocentesis has been the most useful procedure in many cases of large pericardial effusion, cardiac tamponade, or pericardial effusion of unknown etiology. The procedure should be performed with the guidance of echocardiography. PMID:23236323

Myocardial Contrast Agents – Safety Considerations and Clinical Efficacy in Stress Echocardiography

Directory of Open Access Journals (Sweden)

Maier Anca

2016-11-01

Full Text Available Transthoracic echocardiographic examination is known to be a safe, non-invasive and reproducible method, used in every day clinical practice to obtain important information about cardiac structure and function. Unfortunately, a significant proportion of studies have highlighted the considerable technically difficultly in producing diagnostic images due to a poor acoustic window and more than 33% of patients undergoing stress echocardiography have suboptimal echocardiographic images. All these limitations have led to the use of contrast agents to improve the quality of standard ultrasound examination to provide a better delineation of left ventricle endocardial borders or to obtain information that cannot be achieved by using standard echocardiography, such as assessing myocardial microcirculation and therefore perfusion. This paper sought to review the clinical efficacy and safety of ultrasound contrast agents focusing on stress echocardiography.

Predictive role of stress echocardiography before carotid endarterectomy in patients with coronary artery disease.

Science.gov (United States)

Galyfos, George; Tsioufis, Constantinos; Theodorou, Dimitris; Katsaragakis, Stilianos; Zografos, Georgios; Filis, Konstantinos

2015-07-01

Our aim was to examine the predictive value of preoperative stress echocardiography regarding early myocardial ischemia and late cardiac events after carotid endarterectomy (CEA). Patients with coronary artery disease undergoing CEA were prospectively included in this study. All patients (n = 162) were classified into low, medium, and high cardiac risk group, according to preoperative stress echocardiography. Classification was based on the criteria of the American Society of Echocardiography. For all patients, cTnI was measured before surgery and on postoperative days 1, 3, and 7. Postoperative cTnI values ranging from 0.05 to 0.5 ng/mL were classified as myocardial ischemia; values >0.5 ng/mL were classified as myocardial infarction. Cardiac damage was defined as either myocardial ischemia or infarction. No deaths, strokes, or symptomatic coronary events were observed during the early postoperative period. There were 112 low cardiac risk patients, 42 medium-risk patients, and 8 high-risk patients, according to stress echocardiography findings. Overall, there were 22 patients (14%) that increased their cTnI values postoperatively (12 of low cardiac risk and 10 of medium cardiac risk), and all of them were asymptomatic. None of the high-risk patients showed any troponin increase. Late cardiac events were associated with cTnI increase, although no high-risk patients showed any late event. Preoperative stress echocardiography does not seem to independently recognize patients in high risk for asymptomatic cardiac damage after CEA. Postoperative troponin elevation seems to be more predictive for late adverse cardiac events than preoperative stress echocardiography. © 2014, Wiley Periodicals, Inc.

Stress echocardiography in valvular heart disease: a current appraisal.

Science.gov (United States)

Naji, Peyman; Patel, Krishna; Griffin, Brian P; Desai, Milind Y

2015-03-01

Stress echocardiography is increasingly used in the management of patients with valvular heart disease and can aid in evaluation, risk stratification and clinical decision making in these patients. Evaluation of symptoms, exercise capacity and changes in blood pressure can be done during the exercise portion of the test, whereas echocardiographic portion can reveal changes in severity of disease, pulmonary artery pressure and left ventricular function in response to exercise. These parameters, which are not available at rest, can have diagnostic and prognostic importance. In this article, we will review the indications and diagnostic implications, prognostic implications, and clinical impact of stress echocardiography in decision making and management of patients with valvular heart disease.

Intraoperative transesophageal echocardiography in congenital heart diseases surgery

International Nuclear Information System (INIS)

Ozores Suarez, Francisco Javier; Perez de Ordaz, Luis Bravo

2010-01-01

The intraoperative transesophageal echocardiography is very used in pediatric cardiovascular surgery. The aim of present paper was to determine its impact on the surgery immediate results after a previous experience of authors with this type of procedure

New classes of bi-axially symmetric solutions to four-dimensional Vasiliev higher spin gravity

Energy Technology Data Exchange (ETDEWEB)

Sundell, Per; Yin, Yihao [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago de Chile (Chile)

2017-01-11

We present new infinite-dimensional spaces of bi-axially symmetric asymptotically anti-de Sitter solutions to four-dimensional Vasiliev higher spin gravity, obtained by modifications of the Ansatz used in https://arxiv.org/abs/1107.1217, which gave rise to a Type-D solution space. The current Ansatz is based on internal semigroup algebras (without identity) generated by exponentials formed out of the bi-axial symmetry generators. After having switched on the vacuum gauge function, the resulting generalized Weyl tensor is given by a sum of generalized Petrov type-D tensors that are Kerr-like or 2-brane-like in the asymptotic AdS{sub 4} region, and the twistor space connection is smooth in twistor space over finite regions of spacetime. We provide evidence for that the linearized twistor space connection can be brought to Vasiliev gauge.

Evaluation of regional wall motion abnormalities of the heart. Comparison with Doppler tissue echocardiography, MR-tagging and levocardiography

International Nuclear Information System (INIS)

Kivelitz, D.E.; Enzweiler, C.N.H.; Hamm, B.; Borges, A.C.; Walde, T.; Rutsch, W.; Baumann, G.

2004-01-01

Purpose: To compare the visual analysis of magnetic resonance imaging (MRI) with the tagging technique and Doppler tissue echocardiography with invasive ventriculography in detecting and quantifying regional left ventricular wall motion abnormalities. Materials and Methods: Sixteen patients with coronary artery disease and a history of prior myocardial infarction underwent invasive ventriculography. Doppler tissue echocardiography and MR-tagging within one week. Regional wall motion abnormalities (WMA) were detected in all patients. WMA were graded as normal=1; hypokinetic=2; akinetic=3; or dyskinetic=4. For agreement between MRI, echocardiography, and ventriculography the kappa coefficient (κ) according to Cohen was calculated. Results: The kappa coefficient (κ) was 0.962 for agreement between MRI and echocardiography and 0.602 for agreement between MRI and ventriculography as well as between echocardiography and ventriculography. Conclusion: Reliable analysis of regional left ventricular wall motion abnormalities is feasible using visual analysis of MR-tagging. MRI and Doppler tissue echocardiography detect more WMA than invasive ventriculography and grade them as more severe. (orig.)

Motion of particles on a four-dimensional asymptotically AdS black hole with scalar hair

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, P.A.; Olivares, Marco [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)

2015-10-15

Motivated by black hole solutions with matter fields outside their horizon, we study the effect of these matter fields on the motion of massless and massive particles. We consider as background a four-dimensional asymptotically AdS black hole with scalar hair. The geodesics are studied numerically and we discuss the differences in the motion of particles between the four-dimensional asymptotically AdS black holes with scalar hair and their no-hair limit, that is, Schwarzschild AdS black holes. Mainly, we found that there are bounded orbits like planetary orbits in this background. However, the periods associated to circular orbits are modified by the presence of the scalar hair. Besides, we found that some classical tests such as perihelion precession, deflection of light, and gravitational time delay have the standard value of general relativity plus a correction term coming from the cosmological constant and the scalar hair. Finally, we found a specific value of the parameter associated to the scalar hair, in order to explain the discrepancy between the theory and the observations, for the perihelion precession of Mercury and light deflection. (orig.)

Outpatient echocardiography in the evaluation of innocent murmurs in children: utilisation benchmarking.

Science.gov (United States)

Frias, Patricio A; Oster, Matthew; Daley, Patricia A; Boris, Jeffrey R

2016-03-01

We sought to benchmark the utilisation of echocardiography in the outpatient evaluation of heart murmurs by evaluating two large paediatric cardiology centres. Although criteria exist for appropriate use of echocardiography, there are no benchmarking data demonstrating its utilisation. We performed a retrospective cohort study of outpatients aged between 0 and 18 years at the Sibley Heart Center Cardiology and the Children's Hospital of Philadelphia Division of Cardiology, given a sole diagnosis of "innocent murmur" from 1 July, 2007 to 31 October, 2010. Using internal claims data, we compared the utilisation of echocardiography according to centre, patient age, and physician years of service. Of 23,114 eligible patients (Sibley Heart Center Cardiology: 12,815, Children's Hospital of Philadelphia Division of Cardiology: 10,299), 43.1% (Sibley Heart Center Cardiology: 45.2%, Children's Hospital of Philadelphia Division of Cardiology: 40.4%; p1-5 years had the lowest utilisation (32.7%). In two large paediatric cardiology practices, the overall utilisation of echocardiography by physicians with a sole diagnosis of innocent murmur was similar. There was significant and similar variability in utilisation by provider at both centres. Although these data serve as initial benchmarking, the variability in utilisation highlights the importance of appropriate use criteria.

Transthoracic Doppler echocardiography – noninvasive diagnostic window for coronary flow reserve assessment

Directory of Open Access Journals (Sweden)

Dimitrow Paweł

2003-04-01

Full Text Available Abstract This review focuses on transthoracic Doppler echocardiography as noninvasive method used to assess coronary flow reserve (CFR in a wide spectrum of clinical settings. Transthoracic Doppler echocardiography is rapidly gaining appreciation as popular tool to measure CFR both in stenosed and normal epicardial coronary arteries (predominantly in left anterior descending coronary artery. Post-stenotic CFR measurement is helpful in: functional assessment of moderate stenosis, detection of significant or critical stenosis, monitoring of restenosis after revascularization. In the absence of stenosis in the epicardial coronary artery, decreased CFR enable to detect impaired microvascular vasodilatation in: reperfused myocardial infarct, arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy. In these diseases, noninvasive transthoracic Doppler echocardiography allows for serial CFR evaluations to explore the effect of various pharmacological therapies.

Four-dimensional reconstruction of cultural heritage sites based on photogrammetry and clustering

Science.gov (United States)

Voulodimos, Athanasios; Doulamis, Nikolaos; Fritsch, Dieter; Makantasis, Konstantinos; Doulamis, Anastasios; Klein, Michael

2017-01-01

A system designed and developed for the three-dimensional (3-D) reconstruction of cultural heritage (CH) assets is presented. Two basic approaches are presented. The first one, resulting in an "approximate" 3-D model, uses images retrieved in online multimedia collections; it employs a clustering-based technique to perform content-based filtering and eliminate outliers that significantly reduce the performance of 3-D reconstruction frameworks. The second one is based on input image data acquired through terrestrial laser scanning, as well as close range and airborne photogrammetry; it follows a sophisticated multistep strategy, which leads to a "precise" 3-D model. Furthermore, the concept of change history maps is proposed to address the computational limitations involved in four-dimensional (4-D) modeling, i.e., capturing 3-D models of a CH landmark or site at different time instances. The system also comprises a presentation viewer, which manages the display of the multifaceted CH content collected and created. The described methods have been successfully applied and evaluated in challenging real-world scenarios, including the 4-D reconstruction of the historic Market Square of the German city of Calw in the context of the 4-D-CH-World EU project.

Speckle-tracking echocardiography for predicting outcome in chronic aortic regurgitation during conservative management and after surgery

DEFF Research Database (Denmark)

Olsen, Niels Thue; Søgaard, Peter; Larsson, Henrik B W

2011-01-01

Objectives The aim of this study was to test myocardial deformation imaging using speckle-tracking echocardiography for predicting outcomes in chronic aortic regurgitation. Background In chronic aortic regurgitation, left ventricular (LV) dysfunction must be detected early to allow timely surgery....... Speckle-tracking echocardiography has been proposed for this purpose, but the clinical value of this method in aortic regurgitation has not been established. Methods A longitudinal study was performed in 64 patients with moderate to severe aortic regurgitation. Thirty-five patients were managed...... conservatively with frequent clinical visits and sequential echocardiography and followed for an average of 19 ± 8 months, while 29 patients underwent surgery for the valve lesion and were followed for 6 months post-operatively. Baseline LV function by speckle-tracking and conventional echocardiography...

Significance of blood pool scintigraphy and echocardiography in the investigation of left heart ventricle

International Nuclear Information System (INIS)

Otto, L.; Krosse, B.; Neumann, G.; Rother, T.; Loebe, M.; Otto, J.; Koegler, A.; Wuensche, A.; Schneider, G.

1990-01-01

Left ventricular ejection (LVEF) was assessed by both radionuclide ventriculography and echocardiography. The correlation coefficient of 0.74 revealed a just good agreement. It was better in the range of normal than of pathological values. The analysis of regional wall motion performed by echocardiography was not as reliable as by radionuclide ventriculography. The main advantage of echocardiography is its good spatial resolution. Its domain is the diagnosis of pathomorphological changes including valvular disorders. Advantages of radionuclide ventriculography are good temporal resolution, registration of the third dimension practicability during exercise and as bedside method (nuclear stethoscope). Functional disturbances of both ventricles are its field of application. (author)

Realistic Vendor-Specific Synthetic Ultrasound Data for Quality Assurance of 2-D Speckle Tracking Echocardiography: Simulation Pipeline and Open Access Database.

Science.gov (United States)

Alessandrini, Martino; Chakraborty, Bidisha; Heyde, Brecht; Bernard, Olivier; De Craene, Mathieu; Sermesant, Maxime; D'Hooge, Jan

2018-03-01

Two-dimensional (2-D) echocardiography is the modality of choice in the clinic for the diagnosis of cardiac disease. Hereto, speckle tracking (ST) packages complement visual assessment by the cardiologist by providing quantitative diagnostic markers of global and regional cardiac function (e.g., displacement, strain, and strain-rate). Yet, the reported high vendor-dependence between the outputs of different ST packages raises clinical concern and hampers the widespread dissemination of the ST technology. In part, this is due to the lack of a solid commonly accepted quality assurance pipeline for ST packages. Recently, we have developed a framework to benchmark ST algorithms for 3-D echocardiography by using realistic simulated volumetric echocardiographic recordings. Yet, 3-D echocardiography remains an emerging technology, whereas the compelling clinical concern is, so far, directed to the standardization of 2-D ST only. Therefore, by building upon our previous work, we present in this paper a pipeline to generate realistic synthetic sequences for 2-D ST algorithms. Hereto, the synthetic cardiac motion is obtained from a complex electromechanical heart model, whereas realistic vendor-specific texture is obtained by sampling a real clinical ultrasound recording. By modifying the parameters in our pipeline, we generated an open-access library of 105 synthetic sequences encompassing: 1) healthy and ischemic motion patterns; 2) the most common apical probe orientations; and 3) vendor-specific image quality from seven different systems. Ground truth deformation is also provided to allow performance analysis. The application of the provided data set is also demonstrated in the benchmarking of a recent academic ST algorithm.

Improving your four-dimensional image: traveling through a decade of light-sheet-based fluorescence microscopy research.

Science.gov (United States)

Strobl, Frederic; Schmitz, Alexander; Stelzer, Ernst H K

2017-06-01

Light-sheet-based fluorescence microscopy features optical sectioning in the excitation process. This reduces phototoxicity and photobleaching by up to four orders of magnitude compared with that caused by confocal fluorescence microscopy, simplifies segmentation and quantification for three-dimensional cell biology, and supports the transition from on-demand to systematic data acquisition in developmental biology applications.

TIA Caused by Contrast Echocardiography in Patient with Platypnea-Orthodeoxia.

Science.gov (United States)

Loncar, Goran; Payot, Laurent; Dubois, Mathieu

2015-10-01

Platypnea-orthodeoxia syndrome (POS) is a rare clinical disorder characterized by dyspnea caused by the upright position and relieved at recumbent position. Few cases of POS and stroke were reported in literature, and the association between stroke and POS with evidence of patent foramen ovale (PFO) is rare. Stroke may occur in patients with cardiac shunt who undergo contrast echocardiography. We present a patient with POS who experienced transitory ischemic attack (TIA) most likely caused by injection of agitated saline microbubbles during screen for PFO. No case report of TIA/stroke during contrast echocardiography in patients with POS has previously been published. © 2015, Wiley Periodicals, Inc.

Quantum theory of spinor field in four-dimensional Riemannian space-time

International Nuclear Information System (INIS)

Shavokhina, N.S.

1996-01-01

The review deals with the spinor field in the four-dimensional Riemannian space-time. The field beys the Dirac-Fock-Ivanenko equation. Principles of quantization of the spinor field in the Riemannian space-time are formulated which in a particular case of the plane space-time are equivalent to the canonical rules of quantization. The formulated principles are exemplified by the De Sitter space-time. The study of quantum field theory in the De Sitter space-time is interesting because it itself leads to a method of an invariant well for plane space-time. However, the study of the quantum spinor field theory in an arbitrary Riemannian space-time allows one to take into account the influence of the external gravitational field on the quantized spinor field. 60 refs

Myocardial perfusion SPECT for assessment of left ventricular function and volume- comparison with echocardiography

International Nuclear Information System (INIS)

Cheng Xu; Huang Gang

2004-01-01

Objective: The purpose of this study was to evaluate left ventricular volume and function by gated SPECT and comparison of the results with echocardiography. Methods: 65 Consecutive patients (49 male, 16 female; mean age 61+11 years) who underwent both gated 99m Tc-MIBI myocardial perfusion SPECT and echocardiography within a 15 days period were included in the study. Exclusion criteria were any change in clinical status between acquisition of the gated SPECT and echocardiography studies, acute myocardial infarction occurring less than 7 days before study, and surgical procedures occurring within 30 days of the study. The clinical diagnosis of each patient was not considered, as this was not relevant to the purpose of the study. The diagnoses were as follows: coronary artery disease (n=46), hypertensive heart disease (n=8), old myocardial infarction (n=5), myocarditis (n=2), and routine medical examination(n=4). A dose of 740 MBq of 99 Tc m -sestamibi was administered in resting condition. Gated SPECT images were obtained with ADAC Vertex MCD-AC SPECT system. The raw projection images were reconstructed with filtered back-projection (ramp filter), without attenuation correction. The data, including left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV) were obtained using AUTOQUANT software (ADAC corporation). The echocardiography study used its standard techniques. Two nuclear medicine physicians processed the raw images respectively to evaluate internal reproducibility of gated SPECT. In order to compare the results of gated SPECT with echocardiography on different left ventricular volumes, all patients were divided into two groups (EDV 90 ml, n=34) based by EDV measurements in echocardiography. Results: The correlation coefficient of LVEF, EDV, ESV between SPECT and echocardiography were 0.77, 0.86 and 0.90 respectively. P 0.07). The reproducibility of gated SPECT was excellent. There were no significant differences in

Saline Contrast Echocardiography in the Era of Multimodality Imaging--Importance of "Bubbling It Right".

Science.gov (United States)

Gupta, Saurabh K; Shetkar, Sudhir S; Ramakrishnan, Sivasubramanian; Kothari, Shyam S

2015-11-01

Saline contrast echocardiography is an established imaging modality. Logical interpretation of a carefully performed study is vital to realize its diagnostic potential. In this review, we discuss utility of saline contrast echocardiography in evaluation of various pathologies within and outside the heart other than a patent foramen ovale. © 2015, Wiley Periodicals, Inc.

Real-Space Imaging of Carrier Dynamics of Materials Surfaces by Second-Generation Four-Dimensional Scanning Ultrafast Electron Microscopy

KAUST Repository

Sun, Jingya; Melnikov, Vasily; Khan, Jafar Iqbal; Mohammed, Omar F.

2015-01-01

, we establish a second generation of four-dimensional scanning ultrafast electron microscopy (4D S-UEM) and demonstrate the ability to record time-resolved images (snapshots) of material surfaces with 650 fs and ∼5 nm temporal and spatial resolutions

Power Doppler flow mapping and four-dimensional ultrasound for evaluating tubal patency compared with laparoscopy.

Science.gov (United States)

Soliman, Amr A; Shaalan, Waleed; Abdel-Dayem, Tamer; Awad, Elsayed Elbadawy; Elkassar, Yasser; Lüdders, Dörte; Malik, Eduard; Sallam, Hassan N

2015-12-01

To study the accuracy of four-dimensional (4D) ultrasound and power Doppler flow mapping in detecting tubal patency in women with sub-/infertility, and compare it with laparoscopy and chromopertubation. A prospective study. The study was performed in the outpatient clinic and infertility unit of a university hospital. The sonographic team and laparoscopic team were blinded to the results of each other. Women aged younger than 43 years seeking medical advice due to primary or secondary infertility and who planned to have a diagnostic laparoscopy performed, were recruited to the study after signing an informed consent. All of the recruited patients had power Doppler flow mapping and 4D hysterosalpingo-sonography by injecting sterile saline into the fallopian tubes 1 day before surgery. Registering Doppler signals, while using power Doppler, both at the tubal ostia and fimbrial end and the ability to demonstrate the course of the tube especially the isthmus and fimbrial end, while using 4D mode, was considered a patent tube. Out of 50 recruited patients, 33 women had bilateral patent tubes and five had unilateral patent tubes as shown by chromopertubation during diagnostic laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for two-dimensional power Doppler hysterosalpingography were 94.4%, 100%, 100%, 89.2%, and 96.2%, respectively and for 4D ultrasound were 70.4%, 100%, 100%, 70.4%, and 82.6%, respectively. Four-dimensional saline hysterosalpingography has acceptable accuracy in detecting tubal patency, but is surpassed by power Doppler saline hysterosalpingography. Power Doppler saline hysterosalpingography could be incorporated into the routine sub-/infertility workup. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Utility of Angle Correction for Hemodynamic Measurements with Doppler Echocardiography.

Science.gov (United States)

Sigurdsson, Martin I; Eoh, Eun J; Chow, Vinca W; Waldron, Nathan H; Cleve, Jayne; Nicoara, Alina; Swaminathan, Madhav

2018-04-06

The routine application angle correction (AnC) in hemodynamic measurements with transesophageal echocardiography currently is not recommended but potentially could be beneficial. The authors hypothesized that AnC can be applied reliably and may change grading of aortic stenosis (AS). Retrospective analysis. Single institution, university hospital. During phase I, use of AnC was assessed in 60 consecutive patients with intraoperative transesophageal echocardiography. During phase II, 129 images from a retrospective cohort of 117 cases were used to quantify AS by mean pressure gradient. A panel of observers used custom-written software in Java to measure intra-individual and inter-individual correlation in AnC application, correlation with preoperative transthoracic echocardiography gradients, and regrading of AS after AnC. For phase I, the median AnC was 21 (16-35) degrees, and 17% of patients required no AnC. For phase II, the median AnC was 7 (0-15) degrees, and 37% of assessed images required no AnC. The mean inter-individual and intra-individual correlation for AnC was 0.50 (95% confidence interval [CI] 0.49-0.52) and 0.87 (95% CI 0.82-0.92), respectively. AnC did not improve agreement with the transthoracic echocardiography mean pressure gradient. The mean inter-rater and intra-rater agreement for grading AS severity was 0.82 (95% CI 0.81-0.83) and 0.95 (95% CI 0.91-0.95), respectively. A total of 241 (7%) AS gradings were reclassified after AnC was applied, mostly when the uncorrected mean gradient was within 5 mmHg of the severity classification cutoff. AnC can be performed with a modest inter-rater and intra-rater correlation and high degree of inter-rater and intra-rater agreement for AS severity grading. Copyright © 2018 Elsevier Inc. All rights reserved.

N=12 supersymmetric four-dimensional nonlinear σ-models from nonanticommutative superspace

International Nuclear Information System (INIS)

Hatanaka, Tomoya; Ketov, Sergei V.; Kobayashi, Yoshishige; Sasaki, Shin

2005-01-01

The component structure of a generic N=1/2 supersymmetric nonlinear sigma-model (NLSM) defined in the four-dimensional (Euclidean) nonanticommutative (NAC) superspace is investigated in detail. The most general NLSM is described in terms of arbitrary Kahler potential, and chiral and antichiral superpotentials. The case of a single chiral superfield gives rise to splitting of the NLSM potentials, whereas the case of several chiral superfields results in smearing (or fuzziness) of the NLSM potentials, while both effects are controlled by the auxiliary fields. We eliminate the auxiliary fields by solving their algebraic equations of motion, and demonstrate that the results are dependent upon whether the auxiliary integrations responsible for the fuzziness are performed before or after elimination of the auxiliary fields. There is no ambiguity in the case of splitting, i.e., for a single chiral superfield. Fully explicit results are derived in the case of the N=1/2 supersymmetric NAC-deformed CP n NLSM in four dimensions. Here we find another surprise that our results differ from the N=1/2 supersymmetric CP n NLSM derived by the quotient construction from the N=1/2 supersymmetric NAC-deformed gauge theory. We conclude that an N=1/2 supersymmetric deformation of a generic NLSM from the NAC superspace is not unique

[Safety and efficacy of percutaneous patent ductus arteriosus closure solely under thoracic echocardiography guidance].

Science.gov (United States)

Pan, Xiangbin; Ouyang, Wenbin; Li, Shoujun; Guo, Gaili; Liu, Yao; Zhang, Dawei; Zhang, Fengwen; Pang, Kunjing; Fang, Nengxin; Hu, Shengshou

2015-01-01

To avoid the radiation injuries and use of contrast agent, we assessed the safety and efficacy of percutaneous patent ductus arteriosus closure solely under thoracic echocardiography guidance. From June 2013 to June 2014, thirty patients (mean age: (6.3 ± 2.5) years, mean body weight:(22.5 ± 7.3) kg) with pure patent ductus arteriosus were continuously included in this study. The mean diameter of patent ductus arteriosus was (3.8 ± 0.9) mm. Patients were all treated by percutaneous patent ductus arteriosus closure via right femoral artery solely under thoracic echocardiography guidance. The efficacy of the procedure was evaluated by thoracic echocardiography. Follow-up was performed at one month after procedure. All 30 cases were successfully treated with percutaneous patent ductus arteriosus closure solely under thracic echocardiography guidance. The procedural time was (32.8 ± 5.7) minutes. The mean diameter of Amplatzer ADO II was (4.9 ± 1.0) mm. Postoperative trivial residual shunt occurred in six patients immediately after the procedure. All patients survived without peripheral vascular injury or complications such as cardiac perforation. Hospitalization time was (3.4 ± 0.7) days. At one-month follow-up, no complications such as residual shunt or pericardial effusion were observed. Echocardiography guided percutaneous patent ductus arteriosus closure by femoral artery approach is safe and effective, and can avoid X-ray and the use of contrast agents.

Two-dimensional atom localization via two standing-wave fields in a four-level atomic system

International Nuclear Information System (INIS)

Zhang Hongtao; Wang Hui; Wang Zhiping

2011-01-01

We propose a scheme for the two-dimensional (2D) localization of an atom in a four-level Y-type atomic system. By applying two orthogonal standing-wave fields, the atoms can be localized at some special positions, leading to the formation of sub-wavelength 2D periodic spatial distributions. The localization peak position and number as well as the conditional position probability can be controlled by the intensities and detunings of optical fields.

Physical Stress Echocardiography: Prediction of Mortality and Cardiac Events in Patients with Exercise Test showing Ischemia

Directory of Open Access Journals (Sweden)

Ana Carla Pereira de Araujo

2014-11-01

Full Text Available Background: Studies have demonstrated the diagnostic accuracy and prognostic value of physical stress echocardiography in coronary artery disease. However, the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia is limited. Objective: To evaluate the effectiveness of physical stress echocardiography in the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia. Methods: This is a retrospective cohort in which 866 consecutive patients with exercise test positive for myocardial ischemia, and who underwent physical stress echocardiography were studied. Patients were divided into two groups: with physical stress echocardiography negative (G1 or positive (G2 for myocardial ischemia. The endpoints analyzed were all-cause mortality and major cardiac events, defined as cardiac death and non-fatal acute myocardial infarction. Results: G2 comprised 205 patients (23.7%. During the mean 85.6 ± 15.0-month follow-up, there were 26 deaths, of which six were cardiac deaths, and 25 non-fatal myocardial infarction cases. The independent predictors of mortality were: age, diabetes mellitus, and positive physical stress echocardiography (hazard ratio: 2.69; 95% confidence interval: 1.20 - 6.01; p = 0.016. The independent predictors of major cardiac events were: age, previous coronary artery disease, positive physical stress echocardiography (hazard ratio: 2.75; 95% confidence interval: 1.15 - 6.53; p = 0.022 and absence of a 10% increase in ejection fraction. All-cause mortality and the incidence of major cardiac events were significantly higher in G2 (p < 0. 001 and p = 0.001, respectively. Conclusion: Physical stress echocardiography provides additional prognostic information in patients with exercise test positive for myocardial ischemia.

A four-dimensional virtual hand brain-machine interface using active dimension selection.

Science.gov (United States)

Rouse, Adam G

2016-06-01

Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s(-1) for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

Echocardiography diagnosis of myocardial infarction complications

Directory of Open Access Journals (Sweden)

N.D. Oryshchyn

2016-03-01

Full Text Available Diagnosis and management of myocardial infarction complications are discussed in this article. These complications are associated with high level of mortality and surgery is a main treatment method. High level of suspicion and early diagnosis are essential for appropriate treatment and improvement of prognosis. Echocardiography is a main diagnostic method. Analysis of literature about contemporary management of mechanical complications of myocardial infarction has been performed, case reports are presented.

Healed perivalvular abscess: Incidental finding on transthoracic echocardiography

Directory of Open Access Journals (Sweden)

Vishnu Datt

2014-01-01

Full Text Available A 36-year-old male patient presented with the complaints of palpitations and breathlessness. Preoperative transthoracic echocardiography (TTE revealed a bicuspid aortic valve; severe aortic regurgitation with dilated left ventricle (LV and mild LV systolic dysfunction (ejection fraction 50%. He was scheduled to undergo aortic valve replacement. History was not suggestive of infective endocarditis (IE. Preoperative TTE did not demonstrate any aortic perivalvular abscess. Intraoperative transesophageal echocardiography (TEE examination using the mid-esophageal (ME long-axis view, showed an abscess cavity affecting the aortic valve, which initially was assumed to be a dissection flap, but later confirmed to be an abscess cavity by color Doppler examination. The ME aortic valve short-axis view showed two abscesses; one was at the junction of the non-coronary and left coronary commissure and the other one above the right coronary cusp. Intraoperatively, these findings were confirmed by the surgeons. The case report demonstrates the superiority of TEE over TTE in diagnosing perivalvular abscesses.

On-Orbit Prospective Echocardiography on International Space Station

Science.gov (United States)

Hamilton, Douglas R.; Sargsyan, Ashot E.; Martin, David; Garcia, Kathleen M.; Melton, Shannon; Feiverson, Alan; Dulchavsky, Scott A.

2010-01-01

A number of echocardiographic research projects and experiments have been flown on almost every space vehicle since 1970, but validation of standard methods and the determination of Space Normal cardiac function has not been reported to date. Advanced Diagnostics in Microgravity (ADUM) -remote guided echocardiographic technique provides a novel and effective approach to on-board assessment of cardiac physiology and structure using a just-in-time training algorithm and real-time remote guidance aboard the International Space Station (ISS). The validation of remotely guided echocardiographic techniques provides the procedures and protocols to perform scientific and clinical echocardiography on the ISS and the Moon. The objectives of this study were: 1.To confirm the ability of non-physician astronaut/cosmonaut crewmembers to perform clinically relevant remotely guided echocardiography using the Human Research Facility on board the ISS. 2.To compare the preflight, postflight and in-flight echocardiographic parameters commonly used in clinical medicine.

Echocardiography as a Screening Test for Myocardial Scarring in Children with Hypertrophic Cardiomyopathy

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Gregory Compton

2016-01-01

Full Text Available Introduction. Hypertrophic cardiomyopathy (HCM is burdened with morbidity and mortality including tachyarrhythmias and sudden cardiac death. These complications are attributed in part to the formation of proarrhythmic scars in the myocardium. The presence of extensive LGE is a risk factor for adverse outcomes in HCM. Late gadolinium enhancement (LGE cardiac magnetic resonance imaging (cMRI is the standard for the noninvasive evaluation of myocardial scars. However, echocardiography represents an attractive screening tool for myocardial scarring. The aim of this study was to compare the suitability of echocardiography to detect myocardial scars to the standard of cMRI-LGE. Methods. The cMRI studies and echocardiograms from 56 consecutive children with HCM were independently evaluated for the presence of cMRI-LGE and echocardiographic evidence of scarring by expert readers. Results. Echocardiography had a high sensitivity (93% and negative predictive value (94% in comparison to LGE. The false positive rate was high, leading to a low specificity (37% and a low positive predictive value (35%. Conclusions. Given the poor specificity and positive predictive value, echocardiography is not a suitable screening test for the presence of myocardial scarring in children with HCM. However, children without echocardiographic evidence of myocardial scarring may not need to undergo cardiac magnetic resonance imaging to “rule in” LGE.

Portopulmonary hypertension: Improved detection using CT and echocardiography in combination

International Nuclear Information System (INIS)

Devaraj, Anand; Loveridge, Robert; Bernal, William; Willars, Christopher; Wendon, Julia A.; Auzinger, Georg; Bosanac, Diana; Stefanidis, Konstantinos; Desai, Sujal R.

2014-01-01

To establish the relationship between CT signs of pulmonary hypertension and mean pulmonary artery pressure (mPAP) in patients with liver disease, and to determine the additive value of CT in the detection of portopulmonary hypertension in combination with transthoracic echocardiography. Forty-nine patients referred for liver transplantation were retrospectively reviewed. Measured CT signs included the main pulmonary artery/ascending aorta diameter ratio (PA/AA meas ) and the mean left and right main PA diameter (RLPA meas ). Enlargement of the pulmonary artery compared to the ascending aorta was also assessed visually (PA/AA vis ). CT measurements were correlated with right-sided heart catheter-derived mPAP. The ability of PA/AA vis combined with echocardiogram-derived right ventricular systolic pressure (RVSP) to detect portopulmonary hypertension was tested with ROC analysis. There were moderate correlations between mPAP and both PA/AA meas and RLPA meas (r s = 0.41 and r s = 0.42, respectively; p vis and transthoracic echocardiography-derived RVSP improved the detection of portopulmonary hypertension (AUC = 0.8, p < 0.0001). CT contributes to the non-invasive detection of portopulmonary hypertension when used in a diagnostic algorithm with transthoracic echocardiography. CT may have a role in the pre-liver transplantation triage of patients with portopulmonary hypertension for right-sided heart catheterisation. (orig.)

Discriminatory ability of right atrial volumes with two- and three-dimensional echocardiography to detect elevated right atrial pressure in pulmonary hypertension.

Science.gov (United States)

Ostenfeld, Ellen; Werther-Evaldsson, Anna; Engblom, Henrik; Ingvarsson, Annika; Roijer, Anders; Meurling, Carl; Holm, Johan; Rådegran, Göran; Carlsson, Marcus

2018-03-01

Pulmonary hypertension (PH) patients have high mortality due to right ventricular failure. Predictors of poor prognostic outcome are increased right atrial volume (RAV) and elevated mean right atrial pressure (mRAP). Our aim was to determine whether RAV measured with 2D echocardiography (2DE) and 3D echocardiography (3DE) can detect elevated mRAP in patients evaluated for PH. Of 85 patients prospectively evaluated for PH, 44 patients (63 ± 15 years, 57% female) had 2DE, 3DE and right heart catheterization within 48 h and were in sinus rhythm. Maximum (RAV max ) and minimum (RAV min ) volumes were measured with 3DE. 2D maximum RAV and RA area, inferior vena cava diameter and collapsibility were measured. Invasive mRAP > 8 mmHg was predefined as elevated. RAV max and RAV min correlated with mRAP (r = 0·40 and r = 0·35, P8 mmHg. The optimal threshold was 57 ml m -2 for RAV max , 31 ml m -2 for RAV min and 36 ml m -2 for 2DE RAV. Enlarged RA measures with 2DE and 3DE have better discriminatory ability compared with IVC measures, to detect elevated mRAP in patients evaluated for PH. © 2016 The Authors. Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Tissue doppler echocardiography for evaluating left ventricular functions in obese

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Mecnun Çetin

2013-03-01

Full Text Available Objective: The aim of this study was to investigate theimpact of childhood obesity on ventricular functions usingtissue Doppler echocardiography.Materials and methods: The mitral tissue Doppler signalswere recorded in the apical four-chamber view, with thesample volume placed at the lateral walls of mitral annulus.The mitral flow was examined with the sample Pulse Dopplerpositioned parallely to flow just at the orifice of the mitralleaflets. Twenty obese (mean age, 161.5±25.8 monthsand 20 healthy children (mean age, 151.2±33.5 monthswere included to this study.Results: Body mass index (BMI was significantly higherin obese group (30.92±6.87. Isovolumic relaxation time(IVRT which is one of the left ventricular (LV diastolicfunction parameters was 66.10±7.30 ms in obese group,and 58.70±9.06 ms in the control group. IVRT was significantlyhigher in the obese group (p=0.007. In obesegroup, the mitral annulus tissue Doppler E velocity wasdecreased, flow velocity was increased and decrement inEm/Am ratio was significant. We found significant negativecorrelation between BMI and LV Em/Am ratio. Myocardialperformance index (MPI in obese group and control groupwas 0.50±0.07 and 0.41±0.04, respectively (p<0.001.Between MPI and LV Em/Am ratio there was a significantnegative correlation while MPI showed positive correlationwith BMI. In obese group septal and LV posterior wall thicknesswas shown to be significantly increased compared tothe control group (p<0.001.Conclusion: Our findings, may be important for determinationof the relationship between obesity and cardiovascularrisk factors in children. Tissue Doppler echocardiographicimaging may be useful in revealing this relationship.Key words: obesity, doppler echocardiography, ventricular dysfunction

Feasibility of transesophageal echocardiography in birds without cardiac disease.

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Beaufrère, Hugues; Pariaut, Romain; Nevarez, Javier G; Tully, Thomas N

2010-03-01

To establish a technique of transesophageal echocardiography (TEE) in birds without cardiac disease and describe the imaging planes obtained. Validation study. 18 birds including 3 pigeons (Columbia livia), 3 barred owls (Strix varia), 2 red-tailed hawks (Buteo jamaicensis), 1 goose (Anser anser), 1 mallard duck (Anas platyrhynchos), 1 Muscovy duck (Cairina moschata), 2 brown pelicans (Pelecanus occidentalis), 2 Hispaniolan Amazon parrots (Amazona ventralis), 2 red-fronted macaws (Ara rubrogenys), and 1 military macaw (Ara militaris). For each bird, anesthesia was induced and maintained by use of isoflurane. A pediatric, multiplane transesophageal ultrasound probe was passed into the esophagus and adjusted to the level of the heart for echocardiography. Probe positions were recorded via fluoroscopy, and associated imaging planes were described. TEE was performed successfully in all birds except the pelicans, 1 Hispaniolan Amazon parrot, and the red-fronted macaws. Five imaging planes of the heart were consistently viewed from 3 positions of the probe (identified as caudal, middle, and cranial positions relative to the cardiac silhouette). M-mode echocardiography of the left ventricle and the aortic root was performed. Color flow and spectral Doppler ultrasonographic images of in- and outflow regions were obtained. One Hispaniolan Amazon parrot died as a result of esophageal perforation. TEE examination of birds was feasible and provided a larger number of imaging planes with better resolution and details than those typically achieved via a transcoelomic approach. However, TEE should be performed with caution in psittacines.

Detection of heart disease by open access echocardiography: a retrospective analysis of general practice referrals.

Science.gov (United States)

Chambers, John; Kabir, Saleha; Cajeat, Eric

2014-02-01

Heart disease is difficult to detect clinically and it has been suggested that echocardiography should be available to all patients with possible cardiac symptoms or signs. To analyse the results of 2 years of open access echocardiography for the frequency of structural heart disease according to request. Retrospective database analysis in a teaching hospital open access echocardiography service. Reports of all open access transthoracic echocardiograms between January 2011 and December 2012 were categorised as normal, having minor abnormalities, or significant abnormalities according to the indication. There were 2343 open access echocardiograms performed and there were significant abnormalities in 29%, predominantly valve disease (n = 304, 13%), LV systolic dysfunction (n = 179, 8%), aortic dilatation (n = 80, 3%), or pulmonary hypertension (n = 91, 4%). If echocardiography had been targeted at a high-risk group, 267 with valve disease would have been detected (compared to 127 with murmur alone) and 139 with LV systolic dysfunction (compared to 91 with suspected heart failure alone). Most GP practices requested fewer than 10 studies, but 6 practices requested over 70 studies. Open access echocardiograms are often abnormal but structural disease may not be suspected from the clinical request. Uptake by individual practices is patchy. A targeted expansion of echocardiography in patients with a high likelihood of disease is therefore likely to increase the detection of clinically important pathology.

Angio- and echocardiography: viewing heart defects in more detail

International Nuclear Information System (INIS)

Goodwin, J.K.; Lombard, C.W.

1990-01-01

Angio- and echocardiography can help to confirm the diagnosis or evaluate the severity of a heart defect. Angiograms of dogs with pulmonic stenosis and tetralogy of Fallot are shown. Echocardiographic features of common congenital heart defects are summarized

Use of Intracardiac Echocardiography in Interventional Cardiology: Working With the Anatomy Rather Than Fighting It.

Science.gov (United States)

Enriquez, Andres; Saenz, Luis C; Rosso, Raphael; Silvestry, Frank E; Callans, David; Marchlinski, Francis E; Garcia, Fermin

2018-05-22

The indications for catheter-based structural and electrophysiological procedures have recently expanded to more complex scenarios, in which an accurate definition of the variable individual cardiac anatomy is key to obtain optimal results. Intracardiac echocardiography (ICE) is a unique imaging modality able to provide high-resolution real-time visualization of cardiac structures, continuous monitoring of catheter location within the heart, and early recognition of procedural complications, such as pericardial effusion or thrombus formation. Additional benefits are excellent patient tolerance, reduction of fluoroscopy time, and lack of need for general anesthesia or a second operator. For these reasons, ICE has largely replaced transesophageal echocardiography as ideal imaging modality for guiding certain procedures, such as atrial septal defect closure and catheter ablation of cardiac arrhythmias, and has an emerging role in others, including mitral valvuloplasty, transcatheter aortic valve replacement, and left atrial appendage closure. In electrophysiology procedures, ICE allows integration of real-time images with electroanatomic maps; it has a role in assessment of arrhythmogenic substrate, and it is particularly useful for mapping structures that are not visualized by fluoroscopy, such as the interatrial or interventricular septum, papillary muscles, and intracavitary muscular ridges. Most recently, a three-dimensional (3D) volumetric ICE system has also been developed, with potential for greater anatomic information and a promising role in structural interventions. In this state-of-the-art review, we provide guidance on how to conduct a comprehensive ICE survey and summarize the main applications of ICE in a variety of structural and electrophysiology procedures. © 2018 American Heart Association, Inc.

Euler numbers of four-dimensional rotating black holes with the Euclidean signature

International Nuclear Information System (INIS)

Ma Zhengze

2003-01-01

For a black hole's spacetime manifold in the Euclidean signature, its metric is positive definite and therefore a Riemannian manifold. It can be regarded as a gravitational instanton and a topological characteristic which is the Euler number to which it is associated. In this paper we derive a formula for the Euler numbers of four-dimensional rotating black holes by the integral of the Euler density on the spacetime manifolds of black holes. Using this formula, we obtain that the Euler numbers of Kerr and Kerr-Newman black holes are 2. We also obtain that the Euler number of the Kerr-Sen metric in the heterotic string theory with one boost angle nonzero is 2, which is in accordance with its topology

A Novel Four-Dimensional Energy-Saving and Emission-Reduction System and Its Linear Feedback Control

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Minggang Wang

2012-01-01

Full Text Available This paper reports a new four-dimensional energy-saving and emission-reduction chaotic system. The system is obtained in accordance with the complicated relationship between energy saving and emission reduction, carbon emission, economic growth, and new energy development. The dynamics behavior of the system will be analyzed by means of Lyapunov exponents and equilibrium points. Linear feedback control methods are used to suppress chaos to unstable equilibrium. Numerical simulations are presented to show these results.

Assessment of right ventricular systolic function by tissue Doppler echocardiography

DEFF Research Database (Denmark)

Kjærgaard, Jesper

2012-01-01

This thesis summarizes a series of studies performed in order to assess the clinical usefulness of a novel echocardiographic technology that allows non-invasive assessment of regional right ventricular myocardial velocities and deformation: tissue Doppler echocardiography. While the technology...... is a promising tool for improving our understanding of right ventricular hemodynamics, several aspects of the technology must be evaluated. The accuracy and reproducibility of the technology is evaluated in vitro, and normal values, impact of changes in loading of the right ventricle, response to exercise...... on right ventricular hemodynamics: pulmonary embolism, Arrhythmogenic right ventricular cardiomyopathy and pulmonary regurgitation, the latter in an animal model. The conclusions of the thesis are: Color tissue Doppler echocardiography accurately measures velocities, SR and strain in vitro. No systematic...

Prognostic Value of Echocardiography in Hypertensive Versus Nonhypertensive Participants From the General Population

DEFF Research Database (Denmark)

Modin, Daniel; Biering-Sørensen, Sofie Reumert; Mogelvang, Rasmus

2018-01-01

Hypertension may be the most significant cardiovascular risk factor. Few studies have assessed the prognostic value of echocardiography in hypertensive individuals. This study examines the incremental prognostic value of adding echocardiographic parameters to established risk factors in individuals...... of echocardiography in predicting cardiovascular outcomes in the general population is altered by hypertension. In hypertensive individuals, left ventricular mass index added incremental prognostic value in addition to established risk factors. In nonhypertensive individuals, global longitudinal strain added...

Physiology knowledge plays a role when novices learn technical echocardiography skills

DEFF Research Database (Denmark)

Nielsen, Dorte Guldbrand; Gøtzsche, Ole; Eika, Berit

2010-01-01

Purpose: Little is known about factors of relevance for achieving technical skills of echocardiography (TTE); one of the essential skills defined by the European Society of Cardiology Core Curriculum. In an earlier study we have shown that there is a strong correlation between physiology knowledge...... and interpretation skills of intermediately trained echocardiographers. This study investigates the role of physiology knowledge in the development of echocardiographic technical expertise. Methods: Forty-five physicians (15 novices, 15 intermediates and 15 experts) were evaluated on technical skills. Participants...... of echocardiography relevant physiology knowledge. Results: A strong and significant correlation between expertise level and technical checklist scores was found (r = .76, p

Two-dimensional global longitudinal strain is superior to left ventricular ejection fraction in prediction of outcome in patients with left-sided infective endocarditis

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Alhede, Christina; Crowley, Anna Lisa

2018-01-01

BACKGROUND: Impaired cardiac function is the main predictor of poor outcome in infective endocarditis (IE). Global longitudinal strain (GLS) derived from two-dimensional strain echocardiography has proven superior in prediction of long-term outcome as compared to left ventricular ejection fraction...

Two-dimensional intraventricular flow mapping by digital processing conventional color-Doppler echocardiography images.

Science.gov (United States)

Garcia, Damien; Del Alamo, Juan C; Tanne, David; Yotti, Raquel; Cortina, Cristina; Bertrand, Eric; Antoranz, José Carlos; Perez-David, Esther; Rieu, Régis; Fernandez-Aviles, Francisco; Bermejo, Javier

2010-10-01

Doppler echocardiography remains the most extended clinical modality for the evaluation of left ventricular (LV) function. Current Doppler ultrasound methods, however, are limited to the representation of a single flow velocity component. We thus developed a novel technique to construct 2D time-resolved (2D+t) LV velocity fields from conventional transthoracic clinical acquisitions. Combining color-Doppler velocities with LV wall positions, the cross-beam blood velocities were calculated using the continuity equation under a planar flow assumption. To validate the algorithm, 2D Doppler flow mapping and laser particle image velocimetry (PIV) measurements were carried out in an atrio-ventricular duplicator. Phase-contrast magnetic resonance (MR) acquisitions were used to measure in vivo the error due to the 2D flow assumption and to potential scan-plane misalignment. Finally, the applicability of the Doppler technique was tested in the clinical setting. In vitro experiments demonstrated that the new method yields an accurate quantitative description of the main vortex that forms during the cardiac cycle (mean error for vortex radius, position and circulation). MR image analysis evidenced that the error due to the planar flow assumption is close to 15% and does not preclude the characterization of major vortex properties neither in the normal nor in the dilated LV. These results are yet to be confirmed by a head-to-head clinical validation study. Clinical Doppler studies showed that the method is readily applicable and that a single large anterograde vortex develops in the healthy ventricle while supplementary retrograde swirling structures may appear in the diseased heart. The proposed echocardiographic method based on the continuity equation is fast, clinically-compliant and does not require complex training. This technique will potentially enable investigators to study of additional quantitative aspects of intraventricular flow dynamics in the clinical setting by

On the entropy of four-dimensional near-extremal N = 2 black holes with R2-terms

International Nuclear Information System (INIS)

Gruss, Eyal; Oz, Yaron

2007-01-01

We consider the entropy of four-dimensional near-extremal N = 2 black holes. The Bekenstein-Hawking entropy formula has the structure of the extremal black holes entropy with a shift of the charges depending on the non-extremality parameter and the moduli at infinity. We construct a class of near-extremal horizon solutions with R 2 -terms, and show that the generalized Wald entropy formula exhibits the same property

A Comparative Evaluation of the Linear Dimensional Accuracy of Four Impression Techniques using Polyether Impression Material

OpenAIRE

Manoj, Smita Sara; Cherian, K. P.; Chitre, Vidya; Aras, Meena

2013-01-01

There is much discussion in the dental literature regarding the superiority of one impression technique over the other using addition silicone impression material. However, there is inadequate information available on the accuracy of different impression techniques using polyether. The purpose of this study was to assess the linear dimensional accuracy of four impression techniques using polyether on a laboratory model that simulates clinical practice. The impression material used was Impregu...

TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN PATIENTS WITH CEREBRAL ISCHEMIA

Directory of Open Access Journals (Sweden)

Kavian Ghandehari

2010-12-01

Full Text Available Abstract INTRODUCTION: Transesophageal echocardiography (TEE is superior to Transthoracic echocardiography (TTE in detection of atrial septal defects and aneurysm, aortic atheroma, left atrial thrombus and mitral valve abnormalities. TEE is indicated in young adults with cryptogenic ischemic stroke who are suspected of having cardioembolic mechanism despite non-diagnostic TTE. METHODS: A prospective clinical study was conducted in patients with ischemic stroke or TIA who had TTE done in Ghaem hospital, Mashhad during 2006-2007. Ischemic cerebrovascular events were detected by stroke neurologist. TEE was performed with VIPI3/GE device, USA and a 7 MHz transesophageal probe by an echocardiologist. Patients who did not have TTE before TEE were excluded. Comparison of TEE to TTE results was performed by the echocardiologist and stroke neurologist in each patient. Influence of TEE on therapeutic decisions in each patient was evaluated. RESULTS: Forty-seven patients (20 females, 27 males with a mean age of 42.6±7.3 years were studied. Cardiac and aortic abnormalities were detected in TEE of 35 cases (35/47; 74% with ischemic cerebrovascular events. Cardiac abnormalities of 17 cases (36% were only detectable by TEE. These seventeen cases included 7 patients with PFO, 1 case with ASD, 6 cases with aortic atheroma and 2 patients with clot in the left atrium. Comparing the preventive stroke strategies before and after TEE revealed that it was changed only in two cases (2/47; 4.3% due to performing TEE. These included one patient with a small high-risk PFO and another case with dehicense of mechanical mitral valve. CONCLUSION: TEE revealed cardiac or aortic abnormalities in one-third of the patients with cerebral ischemia and has not been detected by TEE previously. The influence of TEE in therapeutic decisions of patients with ischemic cerebrovascular events is very low.         Keywords: Transesophageal echocardiography, Stroke, Transient Ischemic

Changes in cardiac function and structure in newly diagnosed Graves' disease. A conventional and 2D-speckle tracking echocardiography study.

Science.gov (United States)

Aroditis, K; Pikilidou, M; Vourvouri, E; Hadjistavri, L; Zebekakis, P; Yovos, J; Efthimiadis, G; Karvounis, H

2017-02-01

Overproduction of thyroid hormones leads to structural as well as functional cardiac changes. Conventional echocardiography but also recently developed sophisticated two-dimensional echocardiography speckle (2D-STE) tracking allow elaborate evaluation of these changes. Our purpose was to investigate the effects of thyroid hormones overproduction on the heart in patients with Graves' disease and changes that occur after 6 months thyrostatic therapy. We conducted a prospective, case-control study of 6 months duration. Full echocardiographic assessment at diagnosis and after 6 months of thyrostatic therapy were performed in 44 patients with Graves' disease, aged 37.6 ± 9.1 years. Additionally, 43 euthyroid controls were studied for the same time period. Left ventricular end diastolic diameter (LVEDD) and left ventricular end systolic diameter (LVESD) were higher in the patient group while triscupid annular plane systolic excursion (TAPSE) was lower in the patient group. Moreover, left ventricular (LV) mass index and left atrium (LA) volume index were higher in the Graves' disease group. Diastolic impairment as assessed with conventional echocardiography including tissue Doppler was present in the patient group (E/A ratio 0.87 ± 0.10,). 2D-STE analysis, revealed an increase in the strain rate at the isovolumic relaxation time (SRIVRT, 0.310 ± 0.07 patients versus 0.298 ± 0.09 s -1 controls). Improvement in diastolic and right systolic function as well as in left ventricular structural parameters was observed after restoration of euthyroidism (E/A ratio from 0.87 ± 0.10 versus 0.9 ± 0.08, p < 0.05). Patients with newly diagnosed Graves' showed an improvement in diastolic function, right systolic function and structural parameters after 6 months of thyrostatic treatment.

Extracting and analyzing ejection fraction values from electronic echocardiography reports in a large health maintenance organization.

Science.gov (United States)

Xie, Fagen; Zheng, Chengyi; Yuh-Jer Shen, Albert; Chen, Wansu

2017-12-01

The left ventricular ejection fraction value is an important prognostic indicator of cardiovascular outcomes including morbidity and mortality and is often used clinically to indicate severity of heart disease. However, it is usually reported in free-text echocardiography reports. We developed and validated a computerized algorithm to extract ejection fraction values from echocardiography reports and applied the algorithm to a large volume of unstructured echocardiography reports between 1995 and 2011 in a large health maintenance organization. A total of 621,856 echocardiography reports with a description of ejection fraction values or systolic functions were identified, of which 70 percent contained numeric ejection fraction values and the rest (30%) were text descriptions explicitly indicating the systolic left ventricular function. The 12.1 percent (16.0% for male and 8.4% for female) of these extracted ejection fraction values are <45 percent. Validation conducted based on a random sample of 200 reports yielded 95.0 percent sensitivity and 96.9 percent positive predictive value.

Left ventricular mass and hypertrophy by echocardiography and cardiac magnetic resonance: the multi-ethnic study of atherosclerosis.

Science.gov (United States)

Armstrong, Anderson C; Gjesdal, Ola; Almeida, André; Nacif, Marcelo; Wu, Colin; Bluemke, David A; Brumback, Lyndia; Lima, João A C

2014-01-01

Left ventricular mass (LVM) and hypertrophy (LVH) are important parameters, but their use is surrounded by controversies. We compare LVM by echocardiography and cardiac magnetic resonance (CMR), investigating reproducibility aspects and the effect of echocardiography image quality. We also compare indexing methods within and between imaging modalities for classification of LVH and cardiovascular risk. Multi-Ethnic Study of Atherosclerosis enrolled 880 participants in Baltimore city, 146 had echocardiograms and CMR on the same day. LVM was then assessed using standard techniques. Echocardiography image quality was rated (good/limited) according to the parasternal view. LVH was defined after indexing LVM to body surface area, height(1.7) , height(2.7) , or by the predicted LVM from a reference group. Participants were classified for cardiovascular risk according to Framingham score. Pearson's correlation, Bland-Altman plots, percent agreement, and kappa coefficient assessed agreement within and between modalities. Left ventricular mass by echocardiography (140 ± 40 g) and by CMR were correlated (r = 0.8, P echocardiography image quality. The reproducibility profile had strong correlations and agreement for both modalities. Image quality groups had similar characteristics; those with good images compared to CMR slightly superiorly. The prevalence of LVH tended to be higher with higher cardiovascular risk. The agreement for LVH between imaging modalities ranged from 77% to 98% and the kappa coefficient from 0.10 to 0.76. Echocardiography has a reliable performance for LVM assessment and classification of LVH, with limited influence of image quality. Echocardiography and CMR differ in the assessment of LVH, and additional differences rise from the indexing methods. © 2013. This article is a U.S. Government work and is in the public domain in the USA.

Detection of heart disease by open access echocardiography: a retrospective analysis of general practice referrals

Science.gov (United States)

Chambers, John; Kabir, Saleha; Cajeat, Eric

2014-01-01

Background Heart disease is difficult to detect clinically and it has been suggested that echocardiography should be available to all patients with possible cardiac symptoms or signs. Aim To analyse the results of 2 years of open access echocardiography for the frequency of structural heart disease according to request. Design and setting Retrospective database analysis in a teaching hospital open access echocardiography service. Method Reports of all open access transthoracic echocardiograms between January 2011 and December 2012 were categorised as normal, having minor abnormalities, or significant abnormalities according to the indication. Results There were 2343 open access echocardiograms performed and there were significant abnormalities in 29%, predominantly valve disease (n = 304, 13%), LV systolic dysfunction (n = 179, 8%), aortic dilatation (n = 80, 3%), or pulmonary hypertension (n = 91, 4%). If echocardiography had been targeted at a high-risk group, 267 with valve disease would have been detected (compared to 127 with murmur alone) and 139 with LV systolic dysfunction (compared to 91 with suspected heart failure alone). Most GP practices requested fewer than 10 studies, but 6 practices requested over 70 studies. Conclusion Open access echocardiograms are often abnormal but structural disease may not be suspected from the clinical request. Uptake by individual practices is patchy. A targeted expansion of echocardiography in patients with a high likelihood of disease is therefore likely to increase the detection of clinically important pathology. PMID:24567615

Assessment of left ventricular myocardial function using 16-slice multidetector-row computed tomography: comparison with magnetic resonance imaging and echocardiography

International Nuclear Information System (INIS)

Heuschmid, Martin; Rothfuss, Julia K.; Fenchel, Michael; Stauder, Norbert; Kuettner, Axel; Miller, Stephan; Claussen, Claus D.; Kopp, Andreas F.; Schroeder, Stephen; Burgstahler, Christof; Franow, Andreas; Kuzo, Ronald S.

2006-01-01

To assess functional parameters using multidetector-row computed tomography (MDCT) and echocardiography and to compare the results with magnetic resonance imaging (MRI). End-diastolic-volume (EDV), end-systolic-volume (ESV), stroke-volume (SV), ejection-fraction (EF), and myocardial mass (MM) were calculated based on CT data sets from 52 patients. Echocardiography was performed in 24 of the 52 patients. The results from MDCT and echocardiography were compared with MRI. A strong correlation between MDCT and MRI (r=0.66-0.90) was found for all parameters. Echocardiography revealed a low or moderate correlation (0.05-0.59). Compared to MRI the average differences with MDCT were for EDV 15.1 ml, ESV 10.6 ml, SV 4.5 ml, EF 1.8%, and MM 8.2 g, for EDV determined by echocardiography 36.2 ml, ESV 6.8 ml, and EF 13.9%. Bland-Altman analysis revealed acceptable limits of agreement between MRI and MDCT. MDCT enables reliable quantification of left ventricular function. Echocardiography was found to have only a moderate agreement of functional parameters with MRI. (orig.)

Prosthesis-patient mismatch after transcatheter aortic valve implantation: impact of 2D-transthoracic echocardiography versus 3D-transesophageal echocardiography.

Science.gov (United States)

da Silva, Cristina; Sahlen, Anders; Winter, Reidar; Bäck, Magnus; Rück, Andreas; Settergren, Magnus; Manouras, Aristomenis; Shahgaldi, Kambiz

2014-12-01

To investigate the role of 2D-transthoracic echocardiography (2D-TTE) and 3D-transesophageal echocardiography (3D-TEE) in the determination of aortic annulus size prior transcatheter aortic valve implantation (TAVI) and its' impact on the prevalence of patient prosthesis mismatch (PPM). Echocardiography plays an important role in measuring aortic annulus dimension in patients undergoing TAVI. This has great importance since it determines both eligibility for TAVI and selection of prosthesis type and size, and can be potentially important in preventing an inadequate ratio between the prosthetic valvular orifice and the patient's body surface area, concept known as prosthesis-patient mismatch (PPM). A total of 45 patients were studied pre-TAVI: 20 underwent 3D-TEE (men/women 12/8, age 84.8 ± 5.6) and 25 2D-TTE (men/women 9/16, age 84.4 ± 5.4) in order to measure aortic annulus diameter. The presence of PPM was assessed before hospital discharge and after a mean period of 3 months. Moderate PPM was defined as indexed aortic valve area (AVAi) ≤ 0.85 cm(2)/m(2) and severe PPM as AVAi 3D-TEE and 2D-TTE respectively p value = n.s) and severe PPM occurred in 10 % of the patients who underwent 3D-TEE and in 20 % in those with 2D-TTE (p value = n.s). The echocardiographic evaluation 3 months post-TAVI showed 25 % moderate PPM in the 3D-TEE group compared with 24 % in the 2D-TTE group (p value = n.s) and no cases of severe PPM in the 3DTEE group comparing to 20 % in the 2D-TTE group (p = 0.032). Our results indicate a higher incidence of severe PPM in patients who performed 2DTTE compared to those performing 3DTEE prior TAVI. This suggests that the 3D technique should replace the 2DTTE analysis when investigating the aortic annulus diameter in patients undergoing TAVI.

Spectroscopy of charge transfer complexes of four amino acids as organic two-dimensional conductors

International Nuclear Information System (INIS)

Padhiyar, Ashvin; Patel, A J; Oza, A T

2007-01-01

It is found in this study that four amino acids, namely asparagine, arginine, histidine and glutamine form two-dimensional conducting systems which are charge transfer complexes (CTCs) with organic acceptors like TCNQ, TCNE, chloranil, DDQ, TNF and iodine. It is verified using optical absorption edges that these are 2d conductors like transition metal dichalcogenides obeying absorption functions different from 1d and 3d conductors. This 2d nature is related to the network of intermolecular H-bonding in these complexes, which leads to a global H-bonded network resulting in the absence of local deformation due to the relaxation of strain

Echocardiography-based hemodynamic management of left ventricular diastolic dysfunction: a feasibility and safety study.

Science.gov (United States)

Shillcutt, Sasha K; Montzingo, Candice R; Agrawal, Ankit; Khaleel, Maseeha S; Therrien, Stacey L; Thomas, Walker R; Porter, Thomas R; Brakke, Tara R

2014-11-01

Patients with left ventricular diastolic dysfunction (LVDD) are at increased risk of postoperative adverse events. The primary aim of this study was to evaluate the safety and feasibility of using echocardiography-guided hemodynamic management (EGHEM) during surgery in subjects with LVDD compared to conventional management. The feasibility of using echocardiography to direct a treatment algorithm and clinical outcomes were compared for safety between groups. Subjects were screened for LVDD by preoperative transthoracic echocardiography (TTE) and randomized to the conventional or EGHEM group. Subjects in EGHEM received hemodynamic management based on left ventricular filling patterns on transesophageal echocardiography (TEE). Primary outcomes measured were the feasibility to obtain TEE images and follow a TEE-based treatment algorithm. Safety outcomes also compared the following clinical differences between groups: length of hospitalization, incidence of atrial fibrillation, congestive heart failure (CHF), myocardial infarction, cerebrovascular accident, transient ischemic attack and renal failure measured 30 days postoperatively. Population consisted of 28 surgical subjects (14 in conventional group and 14 in EGHEM group). Mean subject age was 73.4 ± 6.7 years (36% male) in conventional group and 65.9 ± 14.4 years (36% male) in EGHEM group. Procedures included orthopedic (conventional = 29%, EGHEM 36%), general (conventional = 50%, EGHEM = 36%), vascular (conventional = 7%, EGHEM = 21%), and thoracic (conventional = 14%, EGHEM = 7%). There was no statistically significant difference in adverse clinical events between the 2 groups. The EGHEM group had less CHF, atrial fibrillation, and shorter length of stay. Echocardiography-guided hemodynamic management of patients with LVDD during surgery is feasible and may be a safe alternative to conventional management. © 2014, Wiley Periodicals, Inc.

The expression of myocardial injury in cold induced myocardial imaging and echocardiography of systematic scleroderma

International Nuclear Information System (INIS)

Liang Jiugen; Zhu Xiaojun; Jiang Ningyi; Chen Shaoxiong

1999-01-01

The study was performed with cold-induced 99m Tc(MIBI) myocardial imaging (MI) in 23 patients with systematic scleroderma. The left ventricular function and wall motion were also observed by dimensional echocardiography (UCG). 14 patients had myocardial perfusion abnormalities visualized by MI, including 5 cases with fixed defects of 9 segments, 3 cases with reversible defects of 6 segments and 6 cases with both fixed and reversible one of 14 segments. The positive rate in myocardial imaging had no significant differences between patients with and without Raynaud's phenomenon (0.5>P>0.25). Compared with baseline, the ejection fraction, stroke volume, cardiac output were significantly decreased during cold-induced in patients with abnormal myocardial scintigraphy (P<0.05), and had significant difference compared with normal group (P<0.05). 4 cases with cold-induced reversible perfusion defects had anatomically correlated regional ventricular hypokinesia in UCG

Trends in pediatric echocardiography and the yield for congenital heart disease in a major cardiac referral hospital in Cameroon.

Science.gov (United States)

Nkoke, Clovis; Balti, Eric; Menanga, Alain; Dzudie, Anastase; Lekoubou, Alain; Kingue, Samuel; Kengne, Andre Pascal

2017-01-01

Congenital heart disease (CHD) is a common condition in children in Sub-Saharan Africa (SSA), where it is associated with poor outcomes. Diagnosis of CHD in SSA depends essentially on echocardiography, which is available only in few urban referral centers. Our aim was to assess time changes in the pattern of referral for pediatric echocardiography and the subsequent diagnosis of structural CHD in a major SSA city. All pediatric echocardiography performed between 2004 and 2013 at the echocardiography laboratory of the Yaounde General Hospital were reviewed. The primary indication of the study and the presence of structural CHD were recorded. Between 2004 and 2013, 9,390 echocardiograms were performed and 834 (8.9%) children aged 1 day to 15 years underwent echocardiography at the center, and 227 (27.2%) cases of definite structural CHD were diagnosed, with 123 (54.2%) in boys. The most frequent indications for echocardiography were heart murmurs (40%) and the suspicion of CHD (37.4%). The commonest CHD was ventricular septal defect (VSD) (30%) with tetralogy of Fallot being the most frequent cyanotic heart lesion (5.3%). The proportion of pediatric echocardiography decreased from 13.3% in 2004-2005 to 6.1% in 2012-2013 (P=0.001) but not in a linear fashion (P=0.072 for linear trend).The diagnosis of structural CHD increased from 25.1% in 2004-2005 to 27.1% in 2012-2013. This increase however was non-significant (P=0.523) and did not follow a linear trend (P=0.230). The pattern of referral for pediatric echocardiography at this center has changed over time, but diagnosis of structural CHD has remained the same. Improving access to this diagnostic procedure and subsequent treatment of diagnosed CHD will help improving the outcome of the disease in this setting.