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.

Left ventricular thrombi: in vivo detection by indium-111 platelet imaging and two dimensional echocardiography

International Nuclear Information System (INIS)

Stratton, J.R.; Ritchie, J.L.; Hamilton, G.W.; Hammermeister, K.E.; Harker, L.A.

1981-01-01

Indium-111 platelet imaging, which can identify sites of active intravascular platelet deposition, and two dimensional echocardiography, which can identify intracardiac masses, can both be used to detect left ventricular thrombi noninvasively. We compared these techniques in 44 men at risk for thrombi from remote transmural myocardial infarction (31 patients) or cardiomyopathy (13 patients). All 44 patients underwent platelet imaging; 35 underwent echocardiography. On platelet imaging nine patients had thrombi and onehad a possible thrombus. Of these 10 studies, none were positive at 2 hours, 5 were positive at 24 hours and all were positive 48 or 72 hours after platelet labeling. Nine of these patients underwent echocardiography, and all had an intraventricular mass. The findings on platelet scanning were negative in six patients who had positive (four patients) or equivocally positive (two patients) findings on echocardiography. All patients with thrombi detected by either noninvasive method had transmural anterior myocardial infarction with ventricular aneurysm. Of the seven patients who underwent cardiac surgery or autopsy, three had thrombi. Platelet imaging failed to identify one thrombus in a patient in whom imaging was performed only at 24 hours after labeling. There were no false positive platelet images in this group. Five of these seven patients (two with throbi, three without) underwent echocardiography; in all cases the echocardiographic findings agreed with the pathologic findings. Both platelet imaging and echocardiography detect ventricular thrombi. Platelet imaging may detect only the most hematologically active thrombi. Both techniques may help define patients at risk of embolization and may be useful for in vivo assessment of antithrombotic drugs

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.

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

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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.

Three- and four-dimensional ultrasound in fetal echocardiography: an up-to-date overview

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Adriaanse, B.M.; Vugt, J.M.G. van; Haak, M.C.

2016-01-01

Congenital heart diseases (CHD) are the most commonly overlooked lesions in prenatal screening programs. Real-time two-dimensional ultrasound (2DUS) is the conventionally used tool for fetal echocardiography. Although continuous improvements in the hardware and post-processing software have resulted

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

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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.

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.

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.

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.

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

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

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

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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.

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.

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.

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

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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.

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

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.

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

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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.

Right ventricular volume determination by two-dimensional echocardiography and radiography in model hearts using a subtraction method

International Nuclear Information System (INIS)

Krebs, W.; Erbel, R.; Schweizer, P.; Richter, H.A.; Massberg, I.; Meyer, J.; Effert, S.; Henn, G.

1982-01-01

The irregularity and complexity of the right ventricle is the reason why no accurate method for right ventricular volume determination exists. A new method for right ventricular volume determination particularly for two-dimensional echocardiography was developed - it is called subtraction method - and was compared with the pyramid and Simpson's methods. The partial volume of the left ventricle and septum was subtracted from total volume of right and left ventricle including interventricular septum. Thus right ventricular volume resulted. Total and partial volume were computer-assisted calculated by use of biplane methods, preferably Simpson's rule. The method was proved with thinwall silicon-rubber model hearts of the left and right ventricle. Two orthogonal planes in the long-axis were filmed by radiography or scanned in a water bath by two-dimensional echocardiography equivalent to RAO and LAO-projections of cineangiocardiograms or to four- and two-chamber views of apical two-dimensional echocardiograms. For calculation of the major axes of the elliptical sections, summed up by Simpson's rule, they were derived from the LAO-projection and the four-chamber view, respectively, the minor axis approximated from the RAO-projection and the two-chamber view. For comparison of direct-measured volume and two-dimensional echocardiographically determined volume, regression equation was given by y = 1.01 x - 3.2, correlation-coefficient, r = 0.977, and standard error of estimate (SEE) +-10.5 ml. For radiography, regression equation was y = 0.909 x + 13.3, r = 0.983, SEE = +-8.0 ml. For pyramid method and Simpson's rule, higher standard errors and lower correlation coefficients were found. Between radiography and two-dimensional echocardiography a mean difference of 4.3 +- 13.2 ml, using subtraction method, and -10.2 +- 22.9 ml, using pyramid method, as well as -0.6 +- 18.5 ml, using Simpson's rule, were calculated for right ventricular volume measurements. (orig./APR) [de

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

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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.

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

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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.

Prenatal Diagnosis of Fetal Interrupted Aortic Arch Type A by Two-Dimensional Echocardiography and Four-Dimensional Echocardiography with B-Flow Imaging and Spatiotemporal Image Correlation.

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Zhang, Dongyu; Zhang, Ying; Ren, Weidong; Sun, Feifei; Guo, Yajun; Sun, Wei; Wang, Yu; Huang, Liping; Cai, Ailu

2016-01-01

Fetal interrupted aortic arch (IAA) is a rare cardiac anomaly and its prenatal diagnosis is challenging. The purpose of our report is to evaluate the use of two-dimensional echocardiography (2DE) and 4D echocardiography with B-flow imaging and spatiotemporal image correlation (4D BF-STIC) in detecting IAA type A (IAA-A). Twenty-three cases of confirmed IAA-A identified by fetal echocardiography were involved in the study. The fetal echocardiography image data were reviewed to analyze the ratio of right ventricle to left ventricle (RV/LV) diameter, the ratio of main pulmonary artery to ascending aorta (MPA/AAO) diameter, and the correlation of RV/LV diameter ratio and size of ventricular septal defect (VSD). 4D BF-STIC was performed in 21 fetuses using the sagittal view (4D BF-STIC-sagittal) and the four-chamber view (4D BF-STIC-4CV) as initial planes of view. An additional 183 normal fetuses were also included in our study. RV/LV and MPA/AAO ratios were calculated and compared with that of IAA-A fetuses. Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV were used to visualize the aortic arch and its associated neck vessels. Six subgroups were evaluated according to gestational age. Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV made the correct prenatal diagnosis of IAA-A in 19/23 (82.6%), 14/21 (66.7%), and 19/21 (90.5%) of patients, respectively. A significantly enlarged MPA combined with symmetric ventricles was found in the IAA-A fetuses, while the size of the VSD was negatively correlated with RV/LV ratio. 4D BF-STIC-sagittal and 4D BF-STIC-4CV were better than traditional 2D ultrasound in detecting the aortic arch and neck vessels between 17 and 28 gestational weeks and 29 to 40 gestational weeks in normal fetuses. It is demonstrated that IAA-A could be diagnosed by traditional fetal echocardiography, while 4D technique could better display the anatomic structure and the spatial relationships of the great arteries. Use of volume reconstruction may

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

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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.

[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.

Three-dimensional echocardiographic assessment of atrial septal defects

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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.

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.

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

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.)

Quantitative assessment of left ventricular systolic function using 3-dimensional echocardiography

Directory of Open Access Journals (Sweden)

Rahul Mehrotra

2013-09-01

Full Text Available Assessment of left ventricular systolic function is the commonest and one of the most important indications for performance of echocardiography. It is important for prognostication, determination of treatment plan, for decisions related to expensive device therapies and for assessing response to treatment. The current methods based on two-dimensional echocardiography are not reliable, have high degree of inter-observer and intra-observer variability and are based on presumptions about the geometry of left ventricle (LV. Real-time three-dimensional echocardiography (RT3DE on the other hand is fast, easy, accurate, relatively operator independent and is not based on any assumptions related to the shape of LV. Owing to these advantages, it is the Echocardiographic modality of choice for assessment of systolic function of the LV. We describe here a step by step approach to evaluation of LV volumes, ejection fraction, regional systolic function and Dyssynchrony analysis based on RT3DE. It has been well validated in clinical studies and is rapidly being incorporated in routine clinical practice.

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

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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

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

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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.

Four-dimensional echocardiography area strain combined with exercise stress echocardiography to evaluate left ventricular regional systolic function in patients with mild single vessel coronary artery stenosis.

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Deng, Yan; Peng, Long; Liu, Yuan-Yuan; Yin, Li-Xue; Li, Chun-Mei; Wang, Yi; Rao, Li

2017-09-01

The aim of this prospective study was to assess the diagnosis value of four-dimensional echocardiography area strain (AS) combined with exercise stress echocardiography to evaluate left ventricular regional systolic function in patients with mild single vessel coronary artery stenosis. Based on treadmill exercise load status, two-dimensional conventional echocardiography and four-dimensional echocardiography area strain were performed on patients suspected coronary artery disease before coronary angiogram. Thirty patients (case group) with mild left anterior descending coronary artery stenosis (stenosis Four-dimensional echocardiography area strain combined with exercise stress echocardiography could sensitively find left ventricular regional systolic function abnormality in patients with mild single vessel coronary artery stenosis, and locate stenosis coronary artery accordingly. © 2017, Wiley Periodicals, Inc.

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

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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.

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

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

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.

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

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.

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

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

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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.

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.

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

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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

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.

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.

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.

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

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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

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

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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.

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.

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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.

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.

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.)

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.

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

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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.

Structures of two-dimensional three-body systems

International Nuclear Information System (INIS)

Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.

1996-01-01

Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)

Two- and three-dimensional CT analysis of ankle fractures

International Nuclear Information System (INIS)

Magid, D.; Fishman, E.K.; Ney, D.R.; Kuhlman, J.E.

1988-01-01

CT with coronal and sagittal reformatting (two-dimensional CT) and animated volumetric image rendering (three-dimensional CT) was used to assess ankle fractures. Partial volume limits transaxial CT in assessments of horizontally oriented structures. Two-dimensional CT, being orthogonal to the plafond, superior mortise, talar dome, and tibial epiphysis, often provides the most clinically useful images. Two-dimensional CT is most useful in characterizing potentially confusing fractures, such as Tillaux (anterior tubercle), triplane, osteochondral talar dome, or nondisplaced talar neck fractures, and it is the best study to confirm intraarticular fragments. Two-and three-dimensional CT best indicate the percentage of articular surface involvement and best demonstrate postoperative results or complications (hardware migration, residual step-off, delayed union, DJD, AVN, etc). Animated three-dimensional images are the preferred means of integrating the two-dimensional findings for surgical planning, as these images more closely simulate the clinical problem

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

Echocardiography in the Era of Multimodality Cardiovascular Imaging

Science.gov (United States)

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

Resonance fluorescence based two- and three-dimensional atom localization

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Wahab, Abdul; Rahmatullah; Qamar, Sajid

2016-06-01

Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

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.

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

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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.

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.

Subjective figure reversal in two- and three-dimensional perceptual space.

Science.gov (United States)

Radilová, J; Radil-Weiss, T

1984-08-01

A permanently illuminated pattern of Mach's truncated pyramid can be perceived according to the experimental instruction given, either as a three-dimensional reversible figure with spontaneously changing convex and concave interpretation (in one experiment), or as a two-dimensional reversible figure-ground pattern (in another experiment). The reversal rate was about twice as slow, without the subjects being aware of it, if it was perceived as a three-dimensional figure compared to the situation when it was perceived as two-dimensional. It may be hypothetized that in the three-dimensional case, the process of perception requires more sequential steps than in the two-dimensional one.

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

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.

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

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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.

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

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)

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.

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

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.

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

Directory of Open Access Journals (Sweden)

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.

Surface representations of two- and three-dimensional fluid flow topology

Science.gov (United States)

Helman, James L.; Hesselink, Lambertus

1990-01-01

We discuss our work using critical point analysis to generate representations of the vector field topology of numerical flow data sets. Critical points are located and characterized in a two-dimensional domain, which may be either a two-dimensional flow field or the tangential velocity field near a three-dimensional body. Tangent curves are then integrated out along the principal directions of certain classes of critical points. The points and curves are linked to form a skeleton representing the two-dimensional vector field topology. When generated from the tangential velocity field near a body in a three-dimensional flow, the skeleton includes the critical points and curves which provide a basis for analyzing the three-dimensional structure of the flow separation. The points along the separation curves in the skeleton are used to start tangent curve integrations to generate surfaces representing the topology of the associated flow separations.

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)

The history of echocardiography.

Science.gov (United States)

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

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.

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

Two- and three-dimensional CT evaluation of sacral and pelvic anomalies

International Nuclear Information System (INIS)

Kuhlman, J.E.; Fishman, E.K.; Magid, D.

1988-01-01

Pelvic anomalies are difficult to evaluate with standard techniques. Detailed knowledge of the existing pelvic structures and musculature is essential for successful repair. The authors evaluated 12 patients with complex malformations of the pelvis using two- and three-dimensional imaging. The anomalies included bladder exstrophy (n = 4), cloacal exstrophy (n = 1), duplicated and absent sacrum (n = 3), myelomeningoceles (n = 2), and diastrophic dwarfism (n = 2). The two-dimensional images consisted of sequential coronal and sagittal reconstructions that could be reviewed dynamically on screen. Three-dimensional images were generated on the Pixar imaging computer with use of volumetric rendering. Two- and three-dimensional CT proved complementary in the evaluation of pelvic anomalies, providing optimal information from transaxial CT data

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.

Fusion of three-dimensional X-ray angiography and three-dimensional echocardiography

Energy Technology Data Exchange (ETDEWEB)

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.)

Three-dimensional tokamak equilibria and stellarators with two-dimensional magnetic symmetry

International Nuclear Information System (INIS)

Garabedian, P.R.

1997-01-01

Three-dimensional computer codes have been developed to simulate equilibrium, stability and transport in tokamaks and stellarators. Bifurcated solutions of the tokamak problem suggest that three-dimensional effects may be more important than has generally been thought. Extensive calculations have led to the discovery of a stellarator configuration with just two field periods and with aspect ratio 3.2 that has a magnetic field spectrum B mn with toroidal symmetry. Numerical studies of equilibrium, stability and transport for this new device, called the Modular Helias-like Heliac 2 (MHH2), will be presented. (author)

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.

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.

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.

Volume scanning three-dimensional display with an inclined two-dimensional display and a mirror scanner

Science.gov (United States)

Miyazaki, Daisuke; Kawanishi, Tsuyoshi; Nishimura, Yasuhiro; Matsushita, Kenji

2001-11-01

A new three-dimensional display system based on a volume-scanning method is demonstrated. To form a three-dimensional real image, an inclined two-dimensional image is rapidly moved with a mirror scanner while the cross-section patterns of a three-dimensional object are displayed sequentially. A vector-scan CRT display unit is used to obtain a high-resolution image. An optical scanning system is constructed with concave mirrors and a galvanometer mirror. It is confirmed that three-dimensional images, formed by the experimental system, satisfy all the criteria for human stereoscopic vision.

Two- and three-dimensional evaluation of the acetabulum in the pediatric patient

International Nuclear Information System (INIS)

Magid, D.; Fishman, E.K.; Sponseller, P.D.

1987-01-01

Complex anatomic structures such as the hip and acetabulum are best evaluated with the use of two- and three-dimensional reconstruction techniques and standard transaxial CT data. CT scans of children with various hip pathologies, including congenital hip dislocation, slipped capital femoral epiphyses, hip dysplasias, dwarfism, and acetabular fractures, were reviewed to determine the value of two- and three-dimensional imaging. The advantages of two-dimensional imaging techniques (sequential coronal/sagittal reconstruction) and three-dimensional valumetric imaging techniques (using real-time video display) are illustrated with specific examples

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

On two-dimensionalization of three-dimensional turbulence in shell models

DEFF Research Database (Denmark)

Chakraborty, Sagar; Jensen, Mogens Høgh; Sarkar, A.

2010-01-01

Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model, the signatures of so-called two-dimensionalization effect of three-dimensional incompressible, homogeneous, isotropic fully developed unforced turbulence have been studied and reproduced. Within the framework of shell m......-similar PDFs for longitudinal velocity differences are also presented for the rotating 3D turbulence case....

Two-and three-dimensional CT reconstruction

International Nuclear Information System (INIS)

Fishman, E.K.; Ney, D.R.; Magid, D.

1990-01-01

This paper determines the optimal imaging sequence for creating two- and three-dimensional (2D/3D) skeletal reconstructions from CT data. A cadaver femur, a bone phantom, and a surgically created fracture were scanned with varying protocols to determine the optimal protocol for creating 2D/3D images. The scanning protocols used varying section thickness (2, 4, and 8 mm) as well as scan spacing (2, 3, 4 and 8 mm). All images were reconstructed into 2D data sets with a bicubic interpolation and 3D datasets with volumetric rendering. The results were reviewed by two reviewers to determine the quality of images reconstruction

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

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

On the size distribution of one-, two- and three-dimensional Voronoi cells

International Nuclear Information System (INIS)

Marthinsen, K.

1994-03-01

The present report gives a presentation of the different cell size distribution obtained by computer simulations of random Voronoi cell structures in one-, two- and three-dimensional space. The random Voronoi cells are constructed from cell centroids randomly distributed along a string, in the plane and in three-dimensional space, respectively. The size distributions are based on 2-3 · 10 4 cells. For the spacial polyhedra both the distribution of volumes, areas and radii are presented, and the two latter quantities are compared to the distributions of areas and radii from a planar section through the three-dimensional structure as well as to the corresponding distributions obtained from a pure two-dimensional cell structure. 11 refs., 11 figs

Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging.

Science.gov (United States)

Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho

2004-12-01

A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

Infrared magneto-spectroscopy of two-dimensional and three-dimensional massless fermions: A comparison

Energy Technology Data Exchange (ETDEWEB)

Orlita, M., E-mail: milan.orlita@lncmi.cnrs.fr [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Faugeras, C.; Barra, A.-L.; Martinez, G.; Potemski, M. [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Basko, D. M. [LPMMC UMR 5493, Université Grenoble 1/CNRS, B.P. 166, 38042 Grenoble (France); Zholudev, M. S. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Teppe, F.; Knap, W. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Gavrilenko, V. I. [Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Mikhailov, N. N.; Dvoretskii, S. A. [A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Neugebauer, P. [Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany); Berger, C. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Institut Néel/CNRS-UJF BP 166, F-38042 Grenoble Cedex 9 (France); Heer, W. A. de [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2015-03-21

Here, we report on a magneto-optical study of two distinct systems hosting massless fermions—two-dimensional graphene and three-dimensional HgCdTe tuned to the zero band gap condition at the point of the semiconductor-to-semimetal topological transition. Both materials exhibit, in the quantum regime, a fairly rich magneto-optical response, which is composed from a series of intra- and interband inter-Landau level resonances with for massless fermions typical √(B) dependence. The impact of the system's dimensionality and of the strength of the spin-orbit interaction on the optical response is also discussed.

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.

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...

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

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

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

Predicting transition in two- and three-dimensional separated flows

International Nuclear Information System (INIS)

Cutrone, L.; De Palma, P.; Pascazio, G.; Napolitano, M.

2008-01-01

This paper is concerned with the numerical prediction of two- and three-dimensional transitional separated flows of turbomachinery interest. The recently proposed single-point transition model based on the use of a laminar kinetic energy transport equation is considered, insofar as it does not require to evaluate any integral parameter, such as boundary-layer thickness, and is thus directly applicable to three-dimensional flows. A well established model, combining a transition-onset correlation with an intermittency transport equation, is also used for comparison. Both models are implemented within a Reynolds-averaged Navier-Stokes solver employing a low-Reynolds-number k-ω turbulence model. The performance of the transition models have been evaluated and tested versus well-documented incompressible flows past a flat plate with semi-circular leading edge, namely: tests T3L2, T3L3, T3L5, and T3LA1 of ERCOFTAC, with different Reynolds numbers and free-stream conditions, the last one being characterized by a non-zero pressure gradient. In all computations, the first model has proven as adequate as or superior to the second one and has been then applied with success to two more complex test cases, for which detailed experimental data are available in the literature, namely: the two- and three-dimensional flows through the T106 linear turbine cascade

Iterative Two- and One-Dimensional Methods for Three-Dimensional Neutron Diffusion Calculations

International Nuclear Information System (INIS)

Lee, Hyun Chul; Lee, Deokjung; Downar, Thomas J.

2005-01-01

Two methods are proposed for solving the three-dimensional neutron diffusion equation by iterating between solutions of the two-dimensional (2-D) radial and one-dimensional (1-D) axial solutions. In the first method, the 2-D/1-D equations are coupled using a current correction factor (CCF) with the average fluxes of the lower and upper planes and the axial net currents at the plane interfaces. In the second method, an analytic expression for the axial net currents at the interface of the planes is used for planar coupling. A comparison of the new methods is made with two previously proposed methods, which use interface net currents and partial currents for planar coupling. A Fourier convergence analysis of the four methods was performed, and results indicate that the two new methods have at least three advantages over the previous methods. First, the new methods are unconditionally stable, whereas the net current method diverges for small axial mesh size. Second, the new methods provide better convergence performance than the other methods in the range of practical mesh sizes. Third, the spectral radii of the new methods asymptotically approach zero as the mesh size increases, while the spectral radius of the partial current method approaches a nonzero value as the mesh size increases. Of the two new methods proposed here, the analytic method provides a smaller spectral radius than the CCF method, but the CCF method has several advantages over the analytic method in practical applications

Right heart mechanics in untreated normotensive patients with prediabetes and type 2 diabetes mellitus: a two- and three-dimensional echocardiographic study.

Science.gov (United States)

Tadic, Marijana; Celic, Vera; Cuspidi, Cesare; Ilic, Sanja; Pencic, Biljana; Radojkovic, Jana; Ivanovic, Branislava; Stanisavljevic, Dejana; Kocabay, Gonenc; Marjanovic, Tamara

2015-03-01

The aim of this study was to determine right ventricular (RV) and right atrial (RA) deformation assessed by two-dimensional echocardiographic and three-dimensional echocardiographic (3DE) imaging in patients with prediabetes and type 2 diabetes mellitus. This cross-sectional study included 47 untreated normotensive subjects with prediabetes, 57 recently diagnosed normotensive patients with diabetes, and 54 healthy controls of similar sex and age distributions. All subjects underwent laboratory analyses and complete two-dimensional echocardiographic and 3DE examinations. Three-dimensional echocardiographic RV end-diastolic volume index gradually decreased from controls across patients with diabetes to those with diabetes (69 ± 10 vs 63 ± 8 vs 58 ± 8 mL/m(2), P < .001), whereas 3DE RV end-systolic volume index was higher in controls compared with patients with diabetes and those with diabetes (25 ± 4 vs 23 ± 4 vs 22 ± 4 mL/m(2), P < .001). However, there was no difference in 3DE RV ejection fraction among the three groups (63 ± 4% vs 62 ± 4% vs 61 ± 5%, P = .063). RV and RA global strain and systolic and early diastolic strain rates were decreased in patients with prediabetes and in those with diabetes compared with controls, whereas RV and RA late diastolic strain rates were increased in these patients. Multivariate regression analysis showed that RV global strain was associated with glycated hemoglobin, independent of left ventricular parameters. RV and RA myocardial deformation and function obtained by 3DE and two-dimensional echocardiographic strain, even in normal ranges, were decreased in patients with prediabetes and in those with diabetes compared with controls. The long-term parameter of glucose control was correlated with the right heart mechanics. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

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...

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

Science.gov (United States)

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.

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.

Three-dimensional versus two-dimensional vision in laparoscopy

DEFF Research Database (Denmark)

Sørensen, Stine D; Savran, Mona Meral; Konge, Lars

2016-01-01

were cohort size and characteristics, skill trained or operation performed, instrument used, outcome measures, and conclusions. Two independent authors performed the search and data extraction. RESULTS: Three hundred and forty articles were screened for eligibility, and 31 RCTs were included...... through a two-dimensional (2D) projection on a monitor, which results in loss of depth perception. To counter this problem, 3D imaging for laparoscopy was developed. A systematic review of the literature was performed to assess the effect of 3D laparoscopy. METHODS: A systematic search of the literature...... in the review. Three trials were carried out in a clinical setting, and 28 trials used a simulated setting. Time was used as an outcome measure in all of the trials, and number of errors was used in 19 out of 31 trials. Twenty-two out of 31 trials (71 %) showed a reduction in performance time, and 12 out of 19...

Comparison of two three-dimensional cephalometric analysis computer software.

Science.gov (United States)

Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

2014-10-01

Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Twenty cone beam computed tomography images were obtained using i-CAT(®) imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (University of Illinois at Chicago, Chicago, IL, USA) software. Before and after orthodontic treatments data were analyzed using t-test. Reliability test using interclass correlation coefficient was stronger for InVivoDental5.0 (0.83-0.98) compared with 3DCeph™ (0.51-0.90). Paired t-test comparison of the two softwares shows no statistical significant difference in the measurements made in the two softwares. InVivoDental5.0 measurements are more reproducible and user friendly when compared to 3DCeph™. No statistical difference between the two softwares in linear or angular measurements. 3DCeph™ is more time-consuming in performing three-dimensional analysis compared with InVivoDental5.0.

Three dimensional illustrating - three-dimensional vision and deception of sensibility

Directory of Open Access Journals (Sweden)

Anita Gánóczy

2009-03-01

Full Text Available The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena of movement parallax, which can be used efficiently in making three-dimensional graphics, the Zöllner- and Corridor-illusion. There are present in this paper the visual elements, which contribute to define a plane two-dimensional image in three-dimension: coherent lines, the covering, the measurement changes, the relative altitude state, the abatement of detail profusion, the shadings and the perspective effects of colors.

Quantitative application of Fermi-Dirac functions of two- and three-dimensional systems

International Nuclear Information System (INIS)

Grimmer, D.P.; Luszczynski, K.; Salibi, N.

1981-01-01

Expressions for the various physical parameters of the ideal Fermi-Dirac gas in two dimensions are derived and compared to the corresponding three-dimensional expressions. These derivations show that the Fermi-Dirac functions most applicable to the two-dimensional problem are F/sub o/(eta), F 1 (eta), and F' 0 (eta). Analogous to the work of McDougall and Stoner in three dimensions, these functions and parameters derived from them are tabulated over the range of the argument, -4 3 He monolayer and bulk liquid 3 He nuclear magnetic susceptibilities, respectively, are considered. Calculational procedures of fitting data to theoretical parameters and criteria for judging the quality of fit of data to both two- and three-dimensional Fermi-Dirac values are discussed

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.

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

Magnetic structure of two- and three-dimensional supramolecular compounds

Energy Technology Data Exchange (ETDEWEB)

Decurtins, S.; Schmalle, H.W.; Pellaux, R. [Zurich Univ. (Switzerland); Fischer, P.; Fauth, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ouladdiaf, B. [Institut Max von Laue - Paul Langevin, 75 - Paris (France)

1997-09-01

Supramolecular chiral networks of oxalato-bridged transition metals show either two- or three-dimensional structural features. The magnetic structures of such compounds have been investigated by means of elastic neutron powder diffraction. (author) 2 figs., 2 refs.

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.

Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

Energy Technology Data Exchange (ETDEWEB)

Schultheis, M. [Université de Nice Sophia-Antipolis, CNRS, Observatoire de Côte d' Azur, Laboratoire Lagrange, 06304 Nice Cedex 4 (France); Zasowski, G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Allende Prieto, C. [Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Anders, F.; Chiappini, C. [Leibniz-Institut für Astrophysik Potsdam (AIP), D-14482 Potsdam (Germany); Beaton, R. L.; García Pérez, A. E.; Majewski, S. R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Beers, T. C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Bizyaev, D. [Apache Point Observatory, Sunspot, NM 88349 (United States); Frinchaboy, P. M. [Department of Physics and Astronomy, Texas Christian University, TCU Box 298840, Fort Worth, TX 76129 (United States); Ge, J. [Astronomy Department, University of Florida, Gainesville, FL 32611 (United States); Hearty, F.; Schneider, D. P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Holtzman, J. [New Mexico State University, Las Cruces, NM 88003 (United States); Muna, D. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Nidever, D. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Shetrone, M., E-mail: mathias.schultheis@oca.eu, E-mail: gail.zasowski@gmail.com [McDonald Observatory, The University of Texas at Austin, Austin, TX 78712 (United States)

2014-07-01

Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.

Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

International Nuclear Information System (INIS)

Schultheis, M.; Zasowski, G.; Allende Prieto, C.; Anders, F.; Chiappini, C.; Beaton, R. L.; García Pérez, A. E.; Majewski, S. R.; Beers, T. C.; Bizyaev, D.; Frinchaboy, P. M.; Ge, J.; Hearty, F.; Schneider, D. P.; Holtzman, J.; Muna, D.; Nidever, D.; Shetrone, M.

2014-01-01

Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.

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

Science.gov (United States)

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.

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)

Impurity states in two - and three-dimensional disordered systems

International Nuclear Information System (INIS)

Silva, A.F. da; Fabbri, M.

1984-01-01

We investigate the microscopic structure of the impurity states in two-and three-dimensional (2D and 3d) disordered systems. A cluster model is outlined for the donor impurity density of states (DIDS) of doped semiconductors. It is shown that the impurity states are very sensitive to a change in the dimensionality of the system, i.e from 3D to 2D system. It is found that all eigenstates become localized in 2D disordered system for a large range of concentration. (Author) [pt

Impurity states in two-and three-dimensional disordered systems

International Nuclear Information System (INIS)

Silva, A.F. da; Fabbri, M.

1984-04-01

The microscopic structure of the impurity states in two-and three-dimensional (2D and 3D) disordered systems is investigated. A cluster model is outlined for the donor impurity density of states (DIDS) of doped semiconductors. It is shown that the impurity states are very sensitive to a change in the dimensionality of the system, i.e., from 3D to 2D system. It is found that all eigenstates become localized in 2D disordered system for a large range of concentration. (Author) [pt

Comparison of two three-dimensional cephalometric analysis computer software

OpenAIRE

Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

2014-01-01

Background: Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Materials and Methods: Twenty cone beam computed tomography images were obtained using i-CAT® imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (Unive...

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.

Method for coupling two-dimensional to three-dimensional discrete ordinates calculations

International Nuclear Information System (INIS)

Thompson, J.L.; Emmett, M.B.; Rhoades, W.A.; Dodds, H.L. Jr.

1985-01-01

A three-dimensional (3-D) discrete ordinates transport code, TORT, has been developed at the Oak Ridge National Laboratory for radiation penetration studies. It is not feasible to solve some 3-D penetration problems with TORT, such as a building located a large distance from a point source, because (a) the discretized 3-D problem is simply too big to fit on the computer or (b) the computing time (and corresponding cost) is prohibitive. Fortunately, such problems can be solved with a hybrid approach by coupling a two-dimensional (2-D) description of the point source, which is assumed to be azimuthally symmetric, to a 3-D description of the building, the region of interest. The purpose of this paper is to describe this hybrid methodology along with its implementation and evaluation in the DOTTOR (Discrete Ordinates to Three-dimensional Oak Ridge Transport) code

[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.

Prenatal diagnosis of Beckwith-Wiedemann syndrome by two- and three-dimensional ultrasonography

Directory of Open Access Journals (Sweden)

Edward Araujo Junior

2013-12-01

Full Text Available Beckwith-Wiedemann syndrome is a genetic syndrome characterized by macroglossia, omphalocele, fetal gigantism and neonatal hypoglycemia. The authors report a case of Beckwith-Wiedemann syndrome diagnosed in a 32-year-old primigravida in whom two-dimensional ultrasonography revealed the presence of abdominal wall cyst, macroglossia and polycystic kidneys. Three-dimensional ultrasonography in rendering mode was of great importance to confirm the previous two-dimensional ultrasonography findings.

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.

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.

K-FIX: a computer program for transient, two-dimensional, two-fluid flow. THREED: an extension of the K-FIX code for three-dimensional calculations

International Nuclear Information System (INIS)

Rivard, W.C.; Torrey, M.D.

1978-10-01

The transient, two-dimensional, two-fluid code K-FIX has been extended to perform three-dimensional calculations. This capability is achieved by adding five modification sets of FORTRAN statements to the basic two-dimensional code. The modifications are listed and described, and a complete listing of the three-dimensional code is provided. Results of an example problem are provided for verification

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)

Two- and three dimensional electrons and photons and their supersymmetric partners

International Nuclear Information System (INIS)

Steringa, J.J.

1989-01-01

This thesis contains a study of supersymmetric gauge theories in two and tree spacetime dimensions. Supersymmetric gauge theories in less than four spacetime dimensions are useful for trying out field theoretical methods which ultimately will be applied to realistic models. In ch. 1 all the aspects of field theory that are necessary for later chapters are treated. In ch. 2 sypersymmetry in two- and three-dimensional space time is treated, and superfields and superspace techniques are introduced. With these a simple Abelian supersymmetric gauge theory in two spacetime dimensions is constructed, the Schwinger model. Ch. 3 deals with general properties and a perturbative analysis of the model. Ch. 4 contains a non-perturbative analysis by means of Dyson-Schwinger equations. A supersummetric extension of theSalam-Delbourgo Gauge Technique is presented and is applied with some seccess to the supersymmetric Schwinger model. In ch. 5 prperties of three-dimensional supersymmetric gauge theories are investigated. (author). 55 refs.; 7 figs.; schemes

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.

Echocardiography and cardiac resynchronisation therapy, friends or foes?

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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.

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.

Multilocality and fusion rules on the generalized structure functions in two-dimensional and three-dimensional Navier-Stokes turbulence.

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Gkioulekas, Eleftherios

2016-09-01

Using the fusion-rules hypothesis for three-dimensional and two-dimensional Navier-Stokes turbulence, we generalize a previous nonperturbative locality proof to multiple applications of the nonlinear interactions operator on generalized structure functions of velocity differences. We call this generalization of nonperturbative locality to multiple applications of the nonlinear interactions operator "multilocality." The resulting cross terms pose a new challenge requiring a new argument and the introduction of a new fusion rule that takes advantage of rotational symmetry. Our main result is that the fusion-rules hypothesis implies both locality and multilocality in both the IR and UV limits for the downscale energy cascade of three-dimensional Navier-Stokes turbulence and the downscale enstrophy cascade and inverse energy cascade of two-dimensional Navier-Stokes turbulence. We stress that these claims relate to nonperturbative locality of generalized structure functions on all orders and not the term-by-term perturbative locality of diagrammatic theories or closure models that involve only two-point correlation and response functions.

Biomedical applications of two- and three-dimensional deterministic radiation transport methods

International Nuclear Information System (INIS)

Nigg, D.W.

1992-01-01

Multidimensional deterministic radiation transport methods are routinely used in support of the Boron Neutron Capture Therapy (BNCT) Program at the Idaho National Engineering Laboratory (INEL). Typical applications of two-dimensional discrete-ordinates methods include neutron filter design, as well as phantom dosimetry. The epithermal-neutron filter for BNCT that is currently available at the Brookhaven Medical Research Reactor (BMRR) was designed using such methods. Good agreement between calculated and measured neutron fluxes was observed for this filter. Three-dimensional discrete-ordinates calculations are used routinely for dose-distribution calculations in three-dimensional phantoms placed in the BMRR beam, as well as for treatment planning verification for live canine subjects. Again, good agreement between calculated and measured neutron fluxes and dose levels is obtained

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

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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.

Comparison of two intraoral scanners based on three-dimensional surface analysis

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Kyung-Min Lee

2018-02-01

Full Text Available Abstract Background This in vivo study evaluated the difference of two well-known intraoral scanners used in dentistry, namely iTero (Align Technology and TRIOS (3Shape. Methods Thirty-two participants underwent intraoral scans with TRIOS and iTero scanners, as well as conventional alginate impressions. The scans obtained with the two intraoral scanners were compared with each other and were also compared with the corresponding model scans by means of three-dimensional surface analysis. The average differences between the two intraoral scans on the surfaces were evaluated by color-mapping. The average differences in the three-dimensional direction between each intraoral scans and its corresponding model scan were calculated at all points on the surfaces. Results The average differences between the two intraoral scanners were 0.057 mm at the maxilla and 0.069 mm at the mandible. Color histograms showed that local deviations between the two scanners occurred in the posterior area. As for difference in the three-dimensional direction, there was no statistically significant difference between two scanners. Conclusions Although there were some deviations in visible inspection, there was no statistical significance between the two intraoral scanners.

Simulation for transthoracic echocardiography of aortic valve

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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

Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique.

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Leiter, Jeff R S; de Korompay, Nevin; Macdonald, Lindsey; McRae, Sheila; Froese, Warren; Macdonald, Peter B

2011-08-01

To compare the reliability of tibial tunnel position and angle produced with a standard ACL guide (two-dimensional guide) or Howell 65° Guide (three-dimensional guide) in the coronal and sagittal planes. In the sagittal plane, the dependent variables were the angle of the tibial tunnel relative to the tibial plateau and the position of the tibial tunnel with respect to the most posterior aspect of the tibia. In the coronal plane, the dependent variables were the angle of the tunnel with respect to the medial joint line of the tibia and the medial and lateral placement of the tibial tunnel relative to the most medial aspect of the tibia. The position and angle of the tibial tunnel in the coronal and sagittal planes were determined from anteroposterior and lateral radiographs, respectively, taken 2-6 months postoperatively. The two-dimensional and three-dimensional guide groups included 28 and 24 sets of radiographs, respectively. Tibial tunnel position was identified, and tunnel angle measurements were completed. Multiple investigators measured the position and angle of the tunnel 3 times, at least 7 days apart. The angle of the tibial tunnel in the coronal plane using a two-dimensional guide (61.3 ± 4.8°) was more horizontal (P guide (64.7 ± 6.2°). The position of the tibial tunnel in the sagittal plane was more anterior (P guide group compared to the three-dimensional guide group (43.3 ± 2.9%). The Howell Tibial Guide allows for reliable placement of the tibial tunnel in the coronal plane at an angle of 65°. Tibial tunnels were within the anatomical footprint of the ACL with either technique. Future studies should investigate the effects of tibial tunnel angle on knee function and patient quality of life. Case-control retrospective comparative study, Level III.

Two- to three-dimensional crossover in a dense electron liquid in silicon

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Matmon, Guy; Ginossar, Eran; Villis, Byron J.; Kölker, Alex; Lim, Tingbin; Solanki, Hari; Schofield, Steven R.; Curson, Neil J.; Li, Juerong; Murdin, Ben N.; Fisher, Andrew J.; Aeppli, Gabriel

2018-04-01

Doping of silicon via phosphine exposures alternating with molecular beam epitaxy overgrowth is a path to Si:P substrates for conventional microelectronics and quantum information technologies. The technique also provides a well-controlled material for systematic studies of two-dimensional lattices with a half-filled band. We show here that for a dense (ns=2.8 ×1014 cm-2) disordered two-dimensional array of P atoms, the full field magnitude and angle-dependent magnetotransport is remarkably well described by classic weak localization theory with no corrections due to interaction. The two- to three-dimensional crossover seen upon warming can also be interpreted using scaling concepts developed for anistropic three-dimensional materials, which work remarkably except when the applied fields are nearly parallel to the conducting planes.

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

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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.

Three-dimensional printing in cardiology: Current applications and future challenges.

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Luo, Hongxing; Meyer-Szary, Jarosław; Wang, Zhongmin; Sabiniewicz, Robert; Liu, Yuhao

2017-01-01

Three-dimensional (3D) printing has attracted a huge interest in recent years. Broadly speaking, it refers to the technology which converts a predesigned virtual model to a touchable object. In clinical medicine, it usually converts a series of two-dimensional medical images acquired through computed tomography, magnetic resonance imaging or 3D echocardiography into a physical model. Medical 3D printing consists of three main steps: image acquisition, virtual reconstruction and 3D manufacturing. It is a promising tool for preoperative evaluation, medical device design, hemodynamic simulation and medical education, it is also likely to reduce operative risk and increase operative success. However, the most relevant studies are case reports or series which are underpowered in testing its actual effect on patient outcomes. The decision of making a 3D cardiac model may seem arbitrary since it is mostly based on a cardiologist's perceived difficulty in performing an interventional procedure. A uniform consensus is urgently necessary to standardize the key steps of 3D printing from imaging acquisition to final production. In the future, more clinical trials of rigorous design are possible to further validate the effect of 3D printing on the treatment of cardiovascular diseases. (Cardiol J 2017; 24, 4: 436-444).

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

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)

A two-dimensional Zn coordination polymer with a three-dimensional supramolecular architecture

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Fuhong Liu

2017-10-01

Full Text Available The title compound, poly[bis{μ2-4,4′-bis[(1,2,4-triazol-1-ylmethyl]biphenyl-κ2N4:N4′}bis(nitrato-κOzinc(II], [Zn(NO32(C18H16N62]n, is a two-dimensional zinc coordination polymer constructed from 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl units. It was synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The ZnII cation is located on an inversion centre and is coordinated by two O atoms from two symmetry-related nitrate groups and four N atoms from four symmetry-related 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl ligands, forming a distorted octahedral {ZnN4O2} coordination geometry. The linear 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl ligand links two ZnII cations, generating two-dimensional layers parallel to the crystallographic (132 plane. The parallel layers are connected by C—H...O, C—H...N, C—H...π and π–π stacking interactions, resulting in a three-dimensional supramolecular architecture.

Electron tomography, three-dimensional Fourier analysis and colour prediction of a three-dimensional amorphous biophotonic nanostructure

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Shawkey, Matthew D.; Saranathan, Vinodkumar; Pálsdóttir, Hildur; Crum, John; Ellisman, Mark H.; Auer, Manfred; Prum, Richard O.

2009-01-01

Organismal colour can be created by selective absorption of light by pigments or light scattering by photonic nanostructures. Photonic nanostructures may vary in refractive index over one, two or three dimensions and may be periodic over large spatial scales or amorphous with short-range order. Theoretical optical analysis of three-dimensional amorphous nanostructures has been challenging because these structures are difficult to describe accurately from conventional two-dimensional electron microscopy alone. Intermediate voltage electron microscopy (IVEM) with tomographic reconstruction adds three-dimensional data by using a high-power electron beam to penetrate and image sections of material sufficiently thick to contain a significant portion of the structure. Here, we use IVEM tomography to characterize a non-iridescent, three-dimensional biophotonic nanostructure: the spongy medullary layer from eastern bluebird Sialia sialis feather barbs. Tomography and three-dimensional Fourier analysis reveal that it is an amorphous, interconnected bicontinuous matrix that is appropriately ordered at local spatial scales in all three dimensions to coherently scatter light. The predicted reflectance spectra from the three-dimensional Fourier analysis are more precise than those predicted by previous two-dimensional Fourier analysis of transmission electron microscopy sections. These results highlight the usefulness, and obstacles, of tomography in the description and analysis of three-dimensional photonic structures. PMID:19158016

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

Dynamic 3D echocardiography in virtual reality

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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.

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

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.

Comparison of a three-dimensional and two-dimensional camera system for automated measurement of back posture in dairy cows

NARCIS (Netherlands)

Viazzi, S.; Bahr, C.; Hertem, van T.; Schlageter-Tello, A.; Romanini, C.E.B.; Halachmi, I.; Lokhorst, C.; Berckmans, D.

2014-01-01

In this study, two different computer vision techniques to automatically measure the back posture in dairy cows were tested and evaluated. A two-dimensional and a three-dimensional camera system were used to extract the back posture from walking cows, which is one measurement used by experts to

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

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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.;

Comparison of one-, two-, and three-dimensional models for mass transport of radionuclides

International Nuclear Information System (INIS)

Prickett, T.A.; Voorhees, M.L.; Herzog, B.L.

1980-02-01

This technical memorandum compares one-, two-, and three-dimensional models for studying regional mass transport of radionuclides in groundwater associated with deep repository disposal of high-level radioactive wastes. In addition, this report outlines the general conditions for which a one- or two-dimensional model could be used as an alternate to a three-dimensional model analysis. The investigation includes a review of analytical and numerical models in addition to consideration of such conditions as rock and fluid heterogeneity, anisotropy, boundary and initial conditions, and various geometric shapes of repository sources and sinks. Based upon current hydrologic practice, each review is taken separately and discussed to the extent that the researcher can match his problem conditions with the minimum number of model dimensions necessary for an accurate solution

Measurement of cardiac ventricular volumes using multidetector row computed tomography: comparison of two- and three-dimensional methods

International Nuclear Information System (INIS)

Montaudon, M.; Laffon, E.; Berger, P.; Corneloup, O.; Latrabe, V.; Laurent, F.

2006-01-01

This study compared a three-dimensional volumetric threshold-based method to a two-dimensional Simpson's rule based short-axis multiplanar method for measuring right (RV) and left ventricular (LV) volumes, stroke volumes, and ejection fraction using electrocardiography-gated multidetector computed tomography (MDCT) data sets. End-diastolic volume (EDV) and end-systolic volume (ESV) of RV and LV were measured independently and blindly by two observers from contrast-enhanced MDCT images using commercial software in 18 patients. For RV and LV the three-dimensionally calculated EDV and ESV values were smaller than those provided by two-dimensional short axis (10%, 5%, 15% and 26% differences respectively). Agreement between the two methods was found for LV (EDV/ESV: r=0.974/0.910, ICC=0.905/0.890) but not for RV (r=0.882/0.930, ICC=0.663/0.544). Measurement errors were significant only for EDV of LV using the two-dimensional method. Similar reproducibility was found for LV measurements, but the three-dimensional method provided greater reproducibility for RV measurements than the two-dimensional. The threshold value supported three-dimensional method provides reproducible cardiac ventricular volume measurements, comparable to those obtained using the short-axis Simpson based method. (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.

Surface Reconstruction-Induced Coincidence Lattice Formation Between Two-Dimensionally Bonded Materials and a Three-Dimensionally Bonded Substrate

NARCIS (Netherlands)

Boschker, Jos E.; Momand, Jamo; Bragaglia, Valeria; Wang, Ruining; Perumal, Karthick; Giussani, Alessandro; Kooi, Bart J.; Riechert, Henning; Calarco, Raffaella

Sb2Te3 films are used for studying the epitaxial registry between two-dimensionally bonded (2D) materials and three-dimensional bonded (3D) substrates. In contrast to the growth of 3D materials, it is found that the formation of coincidence lattices between Sb2Te3 and Si(111) depends on the geometry

Tactical Routing Using Two-Dimensional and Three-Dimensional Views of Terrain

National Research Council Canada - National Science Library

St

2001-01-01

Consoles for military and civilian occupations such as air warfare, command and control, air traffic control, piloting, and meteorological forecasting will be capable of displaying three-dimensional (3-D) perspective views...

Optical conductivity of three and two dimensional topological nodal-line semimetals

Science.gov (United States)

Barati, Shahin; Abedinpour, Saeed H.

2017-10-01

The peculiar shape of the Fermi surface of topological nodal-line semimetals at low carrier concentrations results in their unusual optical and transport properties. We analytically investigate the linear optical responses of three- and two-dimensional nodal-line semimetals using the Kubo formula. The optical conductivity of a three-dimensional nodal-line semimetal is anisotropic. Along the axial direction (i.e., the direction perpendicular to the nodal-ring plane), the Drude weight has a linear dependence on the chemical potential at both low and high carrier dopings. For the radial direction (i.e., the direction parallel to the nodal-ring plane), this dependence changes from linear into quadratic in the transition from low into high carrier concentration. The interband contribution into optical conductivity is also anisotropic. In particular, at large frequencies, it saturates to a constant value for the axial direction and linearly increases with frequency along the radial direction. In two-dimensional nodal-line semimetals, no interband optical transition could be induced and the only contribution to the optical conductivity arises from the intraband excitations. The corresponding Drude weight is independent of the carrier density at low carrier concentrations and linearly increases with chemical potential at high carrier doping.

Mechanical stretching for tissue engineering: two-dimensional and three-dimensional constructs.

Science.gov (United States)

Riehl, Brandon D; Park, Jae-Hong; Kwon, Il Keun; Lim, Jung Yul

2012-08-01

Mechanical cell stretching may be an attractive strategy for the tissue engineering of mechanically functional tissues. It has been demonstrated that cell growth and differentiation can be guided by cell stretch with minimal help from soluble factors and engineered tissues that are mechanically stretched in bioreactors may have superior organization, functionality, and strength compared with unstretched counterparts. This review explores recent studies on cell stretching in both two-dimensional (2D) and three-dimensional (3D) setups focusing on the applications of stretch stimulation as a tool for controlling cell orientation, growth, gene expression, lineage commitment, and differentiation and for achieving successful tissue engineering of mechanically functional tissues, including cardiac, muscle, vasculature, ligament, tendon, bone, and so on. Custom stretching devices and lab-specific mechanical bioreactors are described with a discussion on capabilities and limitations. While stretch mechanotransduction pathways have been examined using 2D stretch, studying such pathways in physiologically relevant 3D environments may be required to understand how cells direct tissue development under stretch. Cell stretch study using 3D milieus may also help to develop tissue-specific stretch regimens optimized with biochemical feedback, which once developed will provide optimal tissue engineering protocols.

The use of virtual reality to reimagine two-dimensional representations of three-dimensional spaces

Science.gov (United States)

Fath, Elaine

2015-03-01

A familiar realm in the world of two-dimensional art is the craft of taking a flat canvas and creating, through color, size, and perspective, the illusion of a three-dimensional space. Using well-explored tricks of logic and sight, impossible landscapes such as those by surrealists de Chirico or Salvador Dalí seem to be windows into new and incredible spaces which appear to be simultaneously feasible and utterly nonsensical. As real-time 3D imaging becomes increasingly prevalent as an artistic medium, this process takes on an additional layer of depth: no longer is two-dimensional space restricted to strategies of light, color, line and geometry to create the impression of a three-dimensional space. A digital interactive environment is a space laid out in three dimensions, allowing the user to explore impossible environments in a way that feels very real. In this project, surrealist two-dimensional art was researched and reimagined: what would stepping into a de Chirico or a Magritte look and feel like, if the depth and distance created by light and geometry were not simply single-perspective illusions, but fully formed and explorable spaces? 3D environment-building software is allowing us to step into these impossible spaces in ways that 2D representations leave us yearning for. This art project explores what we gain--and what gets left behind--when these impossible spaces become doors, rather than windows. Using sketching, Maya 3D rendering software, and the Unity Engine, surrealist art was reimagined as a fully navigable real-time digital environment. The surrealist movement and its key artists were researched for their use of color, geometry, texture, and space and how these elements contributed to their work as a whole, which often conveys feelings of unexpectedness or uneasiness. The end goal was to preserve these feelings while allowing the viewer to actively engage with the space.

Three-dimensional reciprocal space x-ray coherent scattering tomography of two-dimensional object.

Science.gov (United States)

Zhu, Zheyuan; Pang, Shuo

2018-04-01

X-ray coherent scattering tomography is a powerful tool in discriminating biological tissues and bio-compatible materials. Conventional x-ray scattering tomography framework can only resolve isotropic scattering profile under the assumption that the material is amorphous or in powder form, which is not true especially for biological samples with orientation-dependent structure. Previous tomography schemes based on x-ray coherent scattering failed to preserve the scattering pattern from samples with preferred orientations, or required elaborated data acquisition scheme, which could limit its application in practical settings. Here, we demonstrate a simple imaging modality to preserve the anisotropic scattering signal in three-dimensional reciprocal (momentum transfer) space of a two-dimensional sample layer. By incorporating detector movement along the direction of x-ray beam, combined with a tomographic data acquisition scheme, we match the five dimensions of the measurements with the five dimensions (three in momentum transfer domain, and two in spatial domain) of the object. We employed a collimated pencil beam of a table-top copper-anode x-ray tube, along with a panel detector to investigate the feasibility of our method. We have demonstrated x-ray coherent scattering tomographic imaging at a spatial resolution ~2 mm and momentum transfer resolution 0.01 Å -1 for the rotation-invariant scattering direction. For any arbitrary, non-rotation-invariant direction, the same spatial and momentum transfer resolution can be achieved based on the spatial information from the rotation-invariant direction. The reconstructed scattering profile of each pixel from the experiment is consistent with the x-ray diffraction profile of each material. The three-dimensional scattering pattern recovered from the measurement reveals the partially ordered molecular structure of Teflon wrap in our sample. We extend the applicability of conventional x-ray coherent scattering tomography to

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 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.

A two-dimensional Zn coordination polymer with a three-dimensional supra-molecular architecture.

Science.gov (United States)

Liu, Fuhong; Ding, Yan; Li, Qiuyu; Zhang, Liping

2017-10-01

The title compound, poly[bis-{μ 2 -4,4'-bis-[(1,2,4-triazol-1-yl)meth-yl]biphenyl-κ 2 N 4 : N 4' }bis-(nitrato-κ O )zinc(II)], [Zn(NO 3 ) 2 (C 18 H 16 N 6 ) 2 ] n , is a two-dimensional zinc coordination polymer constructed from 4,4'-bis-[(1 H -1,2,4-triazol-1-yl)meth-yl]-1,1'-biphenyl units. It was synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Zn II cation is located on an inversion centre and is coordinated by two O atoms from two symmetry-related nitrate groups and four N atoms from four symmetry-related 4,4'-bis-[(1 H -1,2,4-triazol-1-yl)meth-yl]-1,1'-biphenyl ligands, forming a distorted octa-hedral {ZnN 4 O 2 } coordination geometry. The linear 4,4'-bis-[(1 H -1,2,4-triazol-1-yl)meth-yl]-1,1'-biphenyl ligand links two Zn II cations, generating two-dimensional layers parallel to the crystallographic (132) plane. The parallel layers are connected by C-H⋯O, C-H⋯N, C-H⋯π and π-π stacking inter-actions, resulting in a three-dimensional supra-molecular architecture.

Two-dimensional numerical simulation of flow around three-stranded rope

Science.gov (United States)

Wang, Xinxin; Wan, Rong; Huang, Liuyi; Zhao, Fenfang; Sun, Peng

2016-08-01

Three-stranded rope is widely used in fishing gear and mooring system. Results of numerical simulation are presented for flow around a three-stranded rope in uniform flow. The simulation was carried out to study the hydrodynamic characteristics of pressure and velocity fields of steady incompressible laminar and turbulent wakes behind a three-stranded rope. A three-cylinder configuration and single circular cylinder configuration are used to model the three-stranded rope in the two-dimensional simulation. The governing equations, Navier-Stokes equations, are solved by using two-dimensional finite volume method. The turbulence flow is simulated using Standard κ-ɛ model and Shear-Stress Transport κ-ω (SST) model. The drag of the three-cylinder model and single cylinder model is calculated for different Reynolds numbers by using control volume analysis method. The pressure coefficient is also calculated for the turbulent model and laminar model based on the control surface method. From the comparison of the drag coefficient and the pressure of the single cylinder and three-cylinder models, it is found that the drag coefficients of the three-cylinder model are generally 1.3-1.5 times those of the single circular cylinder for different Reynolds numbers. Comparing the numerical results with water tank test data, the results of the three-cylinder model are closer to the experiment results than the single cylinder model results.

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

Science.gov (United States)

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.

Three-Dimensional Computer-Assisted Two-Layer Elastic Models of the Face.

Science.gov (United States)

Ueda, Koichi; Shigemura, Yuka; Otsuki, Yuki; Fuse, Asuka; Mitsuno, Daisuke

2017-11-01

To make three-dimensional computer-assisted elastic models for the face, we decided on five requirements: (1) an elastic texture like skin and subcutaneous tissue; (2) the ability to take pen marking for incisions; (3) the ability to be cut with a surgical knife; (4) the ability to keep stitches in place for a long time; and (5) a layered structure. After testing many elastic solvents, we have made realistic three-dimensional computer-assisted two-layer elastic models of the face and cleft lip from the computed tomographic and magnetic resonance imaging stereolithographic data. The surface layer is made of polyurethane and the inner layer is silicone. Using this elastic model, we taught residents and young doctors how to make several typical local flaps and to perform cheiloplasty. They could experience realistic simulated surgery and understand three-dimensional movement of the flaps.

Design of a rotational three-dimensional nonimaging device by a compensated two-dimensional design process.

Science.gov (United States)

Yang, Yi; Qian, Ke-Yuan; Luo, Yi

2006-07-20

A compensation process has been developed to design rotational three-dimensional (3D) nonimaging devices. By compensating the desired light distribution during a two-dimensional (2D) design process for an extended Lambertian source using a compensation coefficient, the meridian plane of a 3D device with good performance can be obtained. This method is suitable in many cases with fast calculation speed. Solutions to two kinds of optical design problems have been proposed, and the limitation of this compensated 2D design method is discussed.

Coherent structures and flow topology of transitional separated-reattached flow over two and three dimensional geometrical shapes

Science.gov (United States)

Diabil, Hayder Azeez; Li, Xin Kai; Abdalla, Ibrahim Elrayah

2017-09-01

Large-scale organized motions (commonly referred to coherent structures) and flow topology of a transitional separated-reattached flow have been visualised and investigated using flow visualisation techniques. Two geometrical shapes including two-dimensional flat plate with rectangular leading edge and three-dimensional square cylinder are chosen to shed a light on the flow topology and present coherent structures of the flow over these shapes. For both geometries and in the early stage of the transition, two-dimensional Kelvin-Helmholtz rolls are formed downstream of the leading edge. They are observed to be twisting around the square cylinder while they stay flat in the case of the two-dimensional flat plate. For both geometrical shapes, the two-dimensional Kelvin-Helmholtz rolls move downstream of the leading edge and they are subjected to distortion to form three-dimensional hairpin structures. The flow topology in the flat plate is different from that in the square cylinder. For the flat plate, there is a merging process by a pairing of the Kelvin-Helmholtz rolls to form a large structure that breaks down directly into many hairpin structures. For the squire cylinder case, the Kelvin-Helmholtz roll evolves topologically to form a hairpin structure. In the squire cylinder case, the reattachment length is much shorter and a forming of the three-dimensional structures is closer to the leading edge than that in the flat plate case.

From Two- to Three-Dimensional Structures of a Supertetrahedral Boran Using Density Functional Calculations.

Science.gov (United States)

Getmanskii, Iliya V; Minyaev, Ruslan M; Steglenko, Dmitrii V; Koval, Vitaliy V; Zaitsev, Stanislav A; Minkin, Vladimir I

2017-08-14

With help of the DFT calculations and imposing of periodic boundary conditions the geometrical and electronic structures were investigated of two- and three-dimensional boron systems designed on the basis of graphane and diamond lattices in which carbons were replaced with boron tetrahedrons. The consequent studies of two- and three-layer systems resulted in the construction of a three-dimensional supertetrahedral borane crystal structure. The two-dimensional supertetrahedral borane structures with less than seven layers are dynamically unstable. At the same time the three-dimensional superborane systems were found to be dynamically stable. Lack of the forbidden electronic zone for the studied boron systems testifies that these structures can behave as good conductors. The low density of the supertetrahedral borane crystal structures (0.9 g cm -3 ) is close to that of water, which offers the perspective for their application as aerospace and cosmic materials. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

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

Directory of Open Access Journals (Sweden)

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.

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.

Role of four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation in detecting fetal pulmonary veins.

Science.gov (United States)

Sun, Xue; Zhang, Ying; Fan, Miao; Wang, Yu; Wang, Meilian; Siddiqui, Faiza Amber; Sun, Wei; Sun, Feifei; Zhang, Dongyu; Lei, Wenjia; Hu, Guyue

2017-06-01

Prenatal diagnosis of fetal total anomalous pulmonary vein connection (TAPVC) remains challenging for most screening sonographers. The purpose of this study was to evaluate the use of four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation (4D-HDFI) in identifying pulmonary veins in normal and TAPVC fetuses. We retrospectively reviewed and performed 4D-HDFI in 204 normal and 12 fetuses with confirmed diagnosis of TAPVC. Cardiac volumes were available for postanalysis to obtain 4D-rendered images of the pulmonary veins. For the normal fetuses, two other traditional modalities including color Doppler and HDFI were used to detect the number of pulmonary veins and comparisons were made between each of these traditional methods and 4D-HDFI. For conventional echocardiography, HDFI modality was superior to color Doppler in detecting more pulmonary veins in normal fetuses throughout the gestational period. 4D-HDFI was the best method during the second trimester of pregnancy in identifying normal fetal pulmonary veins. 4D-HDFI images vividly depicted the figure, course, and drainage of pulmonary veins in both normal and TAPVC fetuses. HDFI and the advanced 4D-HDFI technique could facilitate identification of the anatomical features of pulmonary veins in both normal and TAPVC fetuses; 4D-HDFI therefore provides additional and more precise information than conventional echocardiography techniques. © 2017, Wiley Periodicals, Inc.

Equatorial spread F studies using SAMI3 with two-dimensional and three-dimensional electrostatics

Directory of Open Access Journals (Sweden)

H. C. Aveiro

2013-12-01

Full Text Available This letter presents a study of equatorial F region irregularities using the NRL SAMI3/ESF model, comparing results using a two-dimensional (2-D and a three-dimensional (3-D electrostatic potential solution. For the 3-D potential solution, two cases are considered for parallel plasma transport: (1 transport based on the parallel ambipolar field, and (2 transport based on the parallel electric field. The results show that the growth rate of the generalized Rayleigh–Taylor instability is not affected by the choice of the potential solution. However, differences are observed in the structures of the irregularities between the 2-D and 3-D solutions. Additionally, the plasma velocity along the geomagnetic field computed using the full 3-D solution shows complex structures that are not captured by the simplified model. This points out that only the full 3-D model is able to fully capture the complex physics of the equatorial F region.

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2005-01-01

The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context, qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2004-01-01

The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by order, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

Prenatal diagnosis of sirenomelia by two-dimensional and three-dimensional skeletal imaging ultrasound.

Science.gov (United States)

Liu, Rong; Chen, Xin-lin; Yang, Xiao-hong; Ma, Hui-jing

2015-12-01

This study sought to evaluate the contribution of two-dimensional ultrasound (2D-US) and three-dimensional skeletal imaging ultrasound (3D-SUIS) in the prenatal diagnosis of sirenomelia. Between September 2010 and April 2014, a prospective study was conducted in a single referral center using 3D-SUIS performed after 2D-US in 10 cases of sirenomelia. Diagnostic accuracy and detailed findings were compared with postnatal three-dimensional helical computed tomography (3D-HCT), radiological findings and autopsy. Pregnancy was terminated in all 10 sirenomelia cases, including 9 singletons and 1 conjoined twin pregnancy, for a total of 5 males and 5 females. These cases of sirenomelia were determined by autopsy and/or chromosomal examination. Initial 2D-US showed that there were 10 cases of oligohydramnios, bilateral renal agenesis, bladder agenesis, single umbilical artery, fusion of the lower limbs and spinal abnormalities; 8 cases of dipus or monopus; 2 cases of apus; and 8 cases of cardiac abnormalities. Subsequent 3D-SUIS showed that there were 9 cases of scoliosis, 10 cases of sacrococcygeal vertebra dysplasia, 3 cases of hemivertebra, 1 case of vertebral fusion, 3 cases of spina bifida, and 5 cases of rib abnormalities. 3D-SUIS identified significantly more skeletal abnormalities than did 2D-US, and its accuracy was 79.5% (70/88) compared with 3D-HCT and radiography. 3D-SUIS seems to be a useful complementary method to 2D-US and may improve the accuracy of identifying prenatal skeletal abnormalities related to sirenomelia.

Three-dimensional effects in fracture mechanics

International Nuclear Information System (INIS)

Benitez, F.G.

1991-01-01

An overall view of the pioneering theories and works, which enlighten the three-dimensional nature of fracture mechanics during the last years is given. the main aim is not an exhaustive reviewing but the displaying of the last developments on this scientific field in a natural way. This work attempts to envisage the limits of disregarding the three-dimensional behaviour in theories, analyses and experiments. Moreover, it tries to draw attention on the scant fervour, although increasing, this three-dimensional nature of fracture has among the scientific community. Finally, a constructive discussion is presented on the use of two-dimensional solutions in the analysis of geometries which bear a three-dimensional configuration. the static two-dimensional solutions and its applications fields are reviewed. also, the static three-dimensional solutions, wherein a comparative analysis with elastoplastic and elastostatic solutions are presented. to end up, the dynamic three-dimensional solutions are compared to the asymptotic two-dimensional ones under the practical applications point of view. (author)

Theory and design of compact hybrid microphone arrays on two-dimensional planes for three-dimensional soundfield analysis.

Science.gov (United States)

Chen, Hanchi; Abhayapala, Thushara D; Zhang, Wen

2015-11-01

Soundfield analysis based on spherical harmonic decomposition has been widely used in various applications; however, a drawback is the three-dimensional geometry of the microphone arrays. In this paper, a method to design two-dimensional planar microphone arrays that are capable of capturing three-dimensional (3D) spatial soundfields is proposed. Through the utilization of both omni-directional and first order microphones, the proposed microphone array is capable of measuring soundfield components that are undetectable to conventional planar omni-directional microphone arrays, thus providing the same functionality as 3D arrays designed for the same purpose. Simulations show that the accuracy of the planar microphone array is comparable to traditional spherical microphone arrays. Due to its compact shape, the proposed microphone array greatly increases the feasibility of 3D soundfield analysis techniques in real-world applications.

Unconventional phases in quantum spin and pseudospin systems in two dimensional and three dimensional lattices

Science.gov (United States)

Xu, Cenke

Several examples of quantum spin systems and pseudo spin systems have been studied, and unconventional states of matters and phase transitions have been realized in all these systems under consideration. In the p +/- ip superconductor Josephson lattice and the p--band cold atomic system trapped in optical lattices, novel phases which behave similarly to 1+1 dimensional systems are realized, despite the fact that the real physical systems are in two or three dimensional spaces. For instance, by employing a spin-wave analysis together with a new duality transformation, we establish the existence and stability of a novel gapless "critical phase", which we refer to as a "bond algebraic liquid". This novel critical phase is analogous to the 1+1 dimensional algebraic boson liquid phase. The reason for the novel physics is that there is a quasilocal gauge symmetry in the effective low energy Hamiltonian. In a spin-1 system on the kagome lattice, and a hard-core boson system on the honeycomb lattice, the low energy physics is controlled by two components of compact U(1) gauge symmetries that emerge at low energy. Making use of the confinement nature of the 2+1 dimensional compact gauge theories and the powerful duality between gauge theories and height field theories, the crystalline phase diagrams are studied for both systems, and the transitions to other phases are also considered. These phase diagrams might be accessible in strongly correlated materials, or atomic systems in optical lattices. A novel quantum ground state of matter is realized in a bosonic model on three dimensional fcc lattice with emergent low energy excitations. The novel phase obtained is a stable gapless boson liquid phase, with algebraic boson density correlations. The stability of this phase is protected against the instanton effect and superfluidity by self-duality and large gauge symmetries on both sides of the duality. The gapless collective excitations of this phase closely resemble the

Advanced numerical methods for three dimensional two-phase flow calculations

Energy Technology Data Exchange (ETDEWEB)

Toumi, I. [Laboratoire d`Etudes Thermiques des Reacteurs, Gif sur Yvette (France); Caruge, D. [Institut de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

1997-07-01

This paper is devoted to new numerical methods developed for both one and three dimensional two-phase flow calculations. These methods are finite volume numerical methods and are based on the use of Approximate Riemann Solvers concepts to define convective fluxes versus mean cell quantities. The first part of the paper presents the numerical method for a one dimensional hyperbolic two-fluid model including differential terms as added mass and interface pressure. This numerical solution scheme makes use of the Riemann problem solution to define backward and forward differencing to approximate spatial derivatives. The construction of this approximate Riemann solver uses an extension of Roe`s method that has been successfully used to solve gas dynamic equations. As far as the two-fluid model is hyperbolic, this numerical method seems very efficient for the numerical solution of two-phase flow problems. The scheme was applied both to shock tube problems and to standard tests for two-fluid computer codes. The second part describes the numerical method in the three dimensional case. The authors discuss also some improvements performed to obtain a fully implicit solution method that provides fast running steady state calculations. Such a scheme is not implemented in a thermal-hydraulic computer code devoted to 3-D steady-state and transient computations. Some results obtained for Pressurised Water Reactors concerning upper plenum calculations and a steady state flow in the core with rod bow effect evaluation are presented. In practice these new numerical methods have proved to be stable on non staggered grids and capable of generating accurate non oscillating solutions for two-phase flow calculations.

Advanced numerical methods for three dimensional two-phase flow calculations

International Nuclear Information System (INIS)

Toumi, I.; Caruge, D.

1997-01-01

This paper is devoted to new numerical methods developed for both one and three dimensional two-phase flow calculations. These methods are finite volume numerical methods and are based on the use of Approximate Riemann Solvers concepts to define convective fluxes versus mean cell quantities. The first part of the paper presents the numerical method for a one dimensional hyperbolic two-fluid model including differential terms as added mass and interface pressure. This numerical solution scheme makes use of the Riemann problem solution to define backward and forward differencing to approximate spatial derivatives. The construction of this approximate Riemann solver uses an extension of Roe's method that has been successfully used to solve gas dynamic equations. As far as the two-fluid model is hyperbolic, this numerical method seems very efficient for the numerical solution of two-phase flow problems. The scheme was applied both to shock tube problems and to standard tests for two-fluid computer codes. The second part describes the numerical method in the three dimensional case. The authors discuss also some improvements performed to obtain a fully implicit solution method that provides fast running steady state calculations. Such a scheme is not implemented in a thermal-hydraulic computer code devoted to 3-D steady-state and transient computations. Some results obtained for Pressurised Water Reactors concerning upper plenum calculations and a steady state flow in the core with rod bow effect evaluation are presented. In practice these new numerical methods have proved to be stable on non staggered grids and capable of generating accurate non oscillating solutions for two-phase flow calculations

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.

Flow Interactions of Two- and Three-Dimensional Networked Bio-Inspired Control Elements in an In-Line Arrangement.

Science.gov (United States)

Kurt, Melike; Moored, Keith

2018-04-19

We present experiments that examine the modes of interaction, the collective performance and the role of three-dimensionality in two pitching propulsors in an in-line arrangement. Both two-dimensional foils and three-dimensional rectangular wings of $AR = 2$ are examined. \\kwm{In contrast to previous work, two interaction modes distinguished as the coherent and branched wake modes are not observed to be directly linked to the propulsive efficiency, although they are linked to peak thrust performance and minimum power consumption as previously described \\cite[]{boschitsch2014propulsive}.} \\kwm{In fact, in closely-spaced propulsors peak propulsive efficiency of the follower occurs near its minimum power and this condition \\kwm{ reveals a} branched wake mode. Alternatively, for propulsors spaced far apart peak propulsive efficiency of the follower occurs near its peak thrust and this condition \\kwm{reveals a} coherent wake mode.} By examining the collective performance, it is discovered that there is an optimal spacing between the propulsors to maximize the collective efficiency. For two-dimensional foils the optimal spacing of $X^* = 0.75$ and the synchrony of $\\phi = 2\\pi /3$ leads to a collective efficiency and thrust enhancement of 50\\% and 32\\%, respectively, as compared to two isolated foils. In comparison, for $AR = 2$ wings the optimal spacing of $X^* = 0.25$ and the synchrony of $\\phi = 7\\pi /6$ leads to a collective efficiency and thrust enhancement of 30\\% and 22\\%, respectively. In addition, at the optimal conditions the collective lateral force coefficients in both the two- and three-dimensional cases are negligible, while operating off these conditions can lead to non-negligible lateral forces. Finally, the peak efficiency of the collective and the follower are shown to have opposite trends with increasing spacing in two- and three-dimensional flows. This is correlated to the breakdown of the impinging vortex on the follower wing in three

A two-dimensional model with three regions for the reflooding study

International Nuclear Information System (INIS)

Motta, A.M.T.; Kinrys, S.; Roberty, N.C.; Carmo, E.G.D. do; Oliveira, L.F.S. de

1982-01-01

A two-dimensional semi-analytical model, with three heat transfer regions is described for the calculation of flood ratio, the length of quenching front and the temperature distribution in the cladding. (E.G.) [pt

A two-dimensional model with three regions for the reflooding study

International Nuclear Information System (INIS)

Motta, A.M.T.; Kinrys, S.; Roberty, N.C.; Carmo, E.G.D. do; Oliveira, L.F.S. de.

1983-02-01

A two-dimensional semi-analytical model, with three heat transfer regions is described for the calculation of flood ratio, the lenght of quenching front and the temperature distribution in the cladding. (E.G.) [pt

[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

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

Science.gov (United States)

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.

Three-dimensional flow in electromagnetically driven shallow two-layer fluids

NARCIS (Netherlands)

Akkermans, R.A.D.; Kamp, L.P.J.; Clercx, H.J.H.; van Heijst, G.J.F.

2010-01-01

Recent experiments on a freely evolving dipolar vortex in a homogeneous shallow fluid layer have clearly shown the existence and evolution of complex three-dimensional 3D flow structures. The present contribution focuses on the 3D structures of a dipolar vortex evolving in a stable shallow two-layer

TWO- AND THREE-DIMENSIONAL SIMULATIONS OF ASTEROID OCEAN IMPACTS

Directory of Open Access Journals (Sweden)

Michael Gittings

2003-01-01

Full Text Available We have performed a series of two-dimensional and three-dimensional simulations of asteroid impacts into an ocean using the SAGE code from Los Alamos National Laboratory and Science Applications International Corporation. The SAGE code is a compressible Eulerian hydrodynamics code using continuous adaptive mesh refinement for following discontinuities with a fine grid while treating the bulk of the simulation more coarsely. We have used realistic equations of state for the atmosphere, sea water, the oceanic crust, and the mantle. In two dimensions, we simulated asteroid impactors moving at 20 km/s vertically through an exponential atmosphere into a 5 km deep ocean. The impactors were composed of mantle material (3.32 g/cc or iron (7.8 g/cc with diameters from 250m to 10 km. In our three-dimensional runs we simulated asteroids of 1 km diameter composed of iron moving at 20 km/s at angles of 45 and 60 degrees from the vertical. All impacts, including the oblique ones, produce a large underwater cavities with nearly vertical walls followed by a collapse starting from the bottom and subsequent vertical jetting. Substantial amounts of water are vaporized and lofted high into the atmosphere. In the larger impacts, significant amounts of crustal and even mantle material are lofted as well. Tsunamis up to a kilometer in initial height are generated by the collapse of the vertical jet. These waves are initially complex in form, and interact strongly with shocks propagating through the water and the crust. The tsunami waves are followed out to 100 km from the point of impact. Their periods and wavelengths show them to be intermediate type waves, and not (in general shallow-water waves. At great distances, the waves decay as the inverse of the distance from the impact point, ignoring sea-floor topography. For all impactors smaller than about 2 km diameter, the impacting body is highly fragmented and its remains lofted into the stratosphere with the water

Influence of Dzyaloshinskii-Moriya interaction and ballistic spin transport in the two and three-dimensional Heisenberg model

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Lima, L. S.

2018-06-01

We study the effect of Dzyaloshisnkii-Moriya interaction on spin transport in the two and three-dimensional Heisenberg antiferromagnetic models in the square lattice and cubic lattice respectively. For the three-dimensional model, we obtain a large peak for the spin conductivity and therefore a finite AC conductivity. For the two-dimensional model, we have gotten the AC spin conductivity tending to the infinity at ω → 0 limit and a suave decreasing in the spin conductivity with increase of ω. We obtain a small influence of the Dzyaloshinskii-Moriya interaction on the spin conductivity in all cases analyzed.

Transition from two-dimensional to three-dimensional melting in Langmuir-Blodgett films

International Nuclear Information System (INIS)

Mukhopadhyay, M.K.; Sanyal, M.K.; Datta, A.; Mukherjee, M.; Geue, Th.; Grenzer, J.; Pietsch, U.

2004-01-01

Results of energy-dispersive x-ray reflectivity and grazing incidence diffraction studies of Langmuir-Blodgett films exhibited evolution of conventional three-dimensional melting from continuous melting, characteristic of two-dimensional systems, as a function of deposited monolayers. Continuous expansion followed by a sharp phase transition of the in-plane lattice was observed before the melting point and found to be independent of number of deposited layers. Evolution of conventional melting with an increase in the number of monolayers could be quantified by measuring stiffness against tilting of the vertical stack of molecules, which are kept together by an internal field. The internal field as defined in this model reduces as the in-plane lattice expands and the sample temperature approaches melting point. The sharpness of the melting transition, which has been approximated by a Langevin function, increases with the number of deposited monolayers

One-dimensional reduction of the three-dimenstional Gross-Pitaevskii equation with two- and three-body interactions

International Nuclear Information System (INIS)

Cardoso, W. B.; Avelar, A. T.; Bazeia, D.

2011-01-01

We deal with the three-dimensional Gross-Pitaevskii equation which is used to describe a cloud of dilute bosonic atoms that interact under competing two- and three-body scattering potentials. We study the case where the cloud of atoms is strongly confined in two spatial dimensions, allowing us to build an unidimensional nonlinear equation,controlled by the nonlinearities and the confining potentials that trap the system along the longitudinal coordinate. We focus attention on specific limits dictated by the cubic and quintic coefficients, and we implement numerical simulations to help us to quantify the validity of the procedure.

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

Science.gov (United States)

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.

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

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).

Integration of fringe projection and two-dimensional digital image correlation for three-dimensional displacements measurements

Science.gov (United States)

Felipe-Sesé, Luis; López-Alba, Elías; Siegmann, Philip; Díaz, Francisco A.

2016-12-01

A low-cost approach for three-dimensional (3-D) full-field displacement measurement is applied for the analysis of large displacements involved in two different mechanical events. The method is based on a combination of fringe projection and two-dimensional digital image correlation (DIC) techniques. The two techniques have been employed simultaneously using an RGB camera and a color encoding method; therefore, it is possible to measure in-plane and out-of-plane displacements at the same time with only one camera even at high speed rates. The potential of the proposed methodology has been employed for the analysis of large displacements during contact experiments in a soft material block. Displacement results have been successfully compared with those obtained using a 3D-DIC commercial system. Moreover, the analysis of displacements during an impact test on a metal plate was performed to emphasize the application of the methodology for dynamics events. Results show a good level of agreement, highlighting the potential of FP + 2D DIC as low-cost alternative for the analysis of large deformations problems.

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

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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.

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.

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.

Three-dimensional magnetospheric equilibrium with isotropic pressure

International Nuclear Information System (INIS)

Cheng, C.Z.

1995-05-01

In the absence of the toroidal flux, two coupled quasi two-dimensional elliptic equilibrium equations have been derived to describe self-consistent three-dimensional static magnetospheric equilibria with isotropic pressure in an optimal (Ψ,α,χ) flux coordinate system, where Ψ is the magnetic flux function, χ is a generalized poloidal angle, α is the toroidal angle, α = φ - δ(Ψ,φ,χ) is the toroidal angle, δ(Ψ,φ,χ) is periodic in φ, and the magnetic field is represented as rvec B = ∇Ψ x ∇α. A three-dimensional magnetospheric equilibrium code, the MAG-3D code, has been developed by employing an iterative metric method. The main difference between the three-dimensional and the two-dimensional axisymmetric solutions is that the field-aligned current and the toroidal magnetic field are finite for the three-dimensional case, but vanish for the two-dimensional axisymmetric case. With the same boundary flux surface shape, the two-dimensional axisymmetric results are similar to the three-dimensional magnetosphere at each local time cross section

Vapour-liquid equilibrium properties for two- and three-dimensional Lennard-Jones fluids from equations of state

International Nuclear Information System (INIS)

Mulero, A.; Cuadros, F; Faundez, C.A.

1999-01-01

Vapour-liquid equilibrium properties for both three- and two-dimensional Lennard-Jones fluids were obtained using simple cubic-in-density equations of state proposed by the authors. Results were compared with those obtained by other workers from computer simulations and also with results given by other more complex semi-theoretical or semi-empirical equations of state. In the three-dimensional case good agreement is found for all properties and all temperatures. In the two-dimensional case only the coexistence densities were compared, producing good agreement for low temperatures only. The present work is the first to give numerical data for the vapour-liquid equilibrium properties of Lennard-Jones fluids calculated from equations of state. Copyright (1999) CSIRO Australia

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.;

Preparation of three-dimensional shaped aluminum alloy foam by two-step foaming

International Nuclear Information System (INIS)

Shang, J.T.; Xuming, Chu; Deping, He

2008-01-01

A novel method, named two-step foaming, was investigated to prepare three-dimensional shaped aluminum alloy foam used in car industry, spaceflight, packaging and related areas. Calculations of thermal decomposition kinetics of titanium hydride showed that there is a considerable amount of hydrogen releasing when the titanium hydride is heated at a relatively high temperature after heated at a lower temperature. The hydrogen mass to sustain aluminum alloy foam, having a high porosity, was also estimated by calculations. Calculations indicated that as-received titanium hydride without any pre-treatment can be used as foaming agents in two-step foaming. The processes of two-step foaming, including preparing precursors and baking, were also studied by experiments. Results showed that, low titanium hydride dispersion temperature, long titanium hydride dispersion time and low precursors porosity are beneficial to prepare three-dimensional shaped aluminum alloy foams with uniform pores

HR Del REMNANT ANATOMY USING TWO-DIMENSIONAL SPECTRAL DATA AND THREE-DIMENSIONAL PHOTOIONIZATION SHELL MODELS

International Nuclear Information System (INIS)

Moraes, Manoel; Diaz, Marcos

2009-01-01

The HR Del nova remnant was observed with the IFU-GMOS at Gemini North. The spatially resolved spectral data cube was used in the kinematic, morphological, and abundance analysis of the ejecta. The line maps show a very clumpy shell with two main symmetric structures. The first one is the outer part of the shell seen in Hα, which forms two rings projected in the sky plane. These ring structures correspond to a closed hourglass shape, first proposed by Harman and O'Brien. The equatorial emission enhancement is caused by the superimposed hourglass structures in the line of sight. The second structure seen only in the [O III] and [N II] maps is located along the polar directions inside the hourglass structure. Abundance gradients between the polar caps and equatorial region were not found. However, the outer part of the shell seems to be less abundant in oxygen and nitrogen than the inner regions. Detailed 2.5-dimensional photoionization modeling of the three-dimensional shell was performed using the mass distribution inferred from the observations and the presence of mass clumps. The resulting model grids are used to constrain the physical properties of the shell as well as the central ionizing source. A sequence of three-dimensional clumpy models including a disk-shaped ionization source is able to reproduce the ionization gradients between polar and equatorial regions of the shell. Differences between shell axial ratios in different lines can also be explained by aspherical illumination. A total shell mass of 9 x 10 -4 M sun is derived from these models. We estimate that 50%-70% of the shell mass is contained in neutral clumps with density contrast up to a factor of 30.

Simplified two and three dimensional HTTR benchmark problems

International Nuclear Information System (INIS)

Zhang Zhan; Rahnema, Farzad; Zhang Dingkang; Pounders, Justin M.; Ougouag, Abderrafi M.

2011-01-01

To assess the accuracy of diffusion or transport methods for reactor calculations, it is desirable to create heterogeneous benchmark problems that are typical of whole core configurations. In this paper we have created two and three dimensional numerical benchmark problems typical of high temperature gas cooled prismatic cores. Additionally, a single cell and single block benchmark problems are also included. These problems were derived from the HTTR start-up experiment. Since the primary utility of the benchmark problems is in code-to-code verification, minor details regarding geometry and material specification of the original experiment have been simplified while retaining the heterogeneity and the major physics properties of the core from a neutronics viewpoint. A six-group material (macroscopic) cross section library has been generated for the benchmark problems using the lattice depletion code HELIOS. Using this library, Monte Carlo solutions are presented for three configurations (all-rods-in, partially-controlled and all-rods-out) for both the 2D and 3D problems. These solutions include the core eigenvalues, the block (assembly) averaged fission densities, local peaking factors, the absorption densities in the burnable poison and control rods, and pin fission density distribution for selected blocks. Also included are the solutions for the single cell and single block problems.

Three-dimensional multi-relaxation-time lattice Boltzmann front-tracking method for two-phase flow

International Nuclear Information System (INIS)

Xie Hai-Qiong; Zeng Zhong; Zhang Liang-Qi

2016-01-01

We developed a three-dimensional multi-relaxation-time lattice Boltzmann method for incompressible and immiscible two-phase flow by coupling with a front-tracking technique. The flow field was simulated by using an Eulerian grid, an adaptive unstructured triangular Lagrangian grid was applied to track explicitly the motion of the two-fluid interface, and an indicator function was introduced to update accurately the fluid properties. The surface tension was computed directly on a triangular Lagrangian grid, and then the surface tension was distributed to the background Eulerian grid. Three benchmarks of two-phase flow, including the Laplace law for a stationary drop, the oscillation of a three-dimensional ellipsoidal drop, and the drop deformation in a shear flow, were simulated to validate the present model. (paper)

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.

Three-dimensional investigation of the two-phase flow structure in a bubbly pipe flow

International Nuclear Information System (INIS)

Schmidl, W.; Hassan, Y.A.; Ortiz-Villafuerte, J.

1996-01-01

Particle image velocimetry (PIV) is a nonintrusive measurement technique that can be used to study the structure of various fluid flows. PIV is used to measure the time-varying, full-field velocity data of a particle-seeded flow field within either a two-dimensional plane or three-dimensional volume. PIV is a very efficient measurement technique since it can obtain both qualitative and quantitative spatial information about the flow field being studied. The quantitative spatial velocity information can be further processed into information of flow parameters such as vorticity and turbulence over extended areas. The objective of this study was to apply recent advances and improvements in the PIV flow measurement technique to the full-field, nonintrusive analysis of a three-dimensional, two-phase fluid flow system in such a manner that both components of the two-phase system could be experimentally quantified

Tensor of effective susceptibility in random magnetic composites: Application to two-dimensional and three-dimensional cases

Science.gov (United States)

Posnansky, Oleg P.

2018-05-01

The measuring of dynamic magnetic susceptibility by nuclear magnetic resonance is used for revealing information about the internal structure of various magnetoactive composites. The response of such material on the applied external static and time-varying magnetic fields encodes intrinsic dynamic correlations and depends on links between macroscopic effective susceptibility and structure on the microscopic scale. In the current work we carried out computational analysis of the frequency dependent dynamic magnetic susceptibility and demonstrated its dependence on the microscopic architectural elements while also considering Euclidean dimensionality. The proposed numerical method is efficient in the simulation of nuclear magnetic resonance experiments in two- and three-dimensional random magnetic media by choosing and modeling the influence of the concentration of components and internal hierarchical characteristics of physical parameters.

Comparison of one-, two-, and three-dimensional measurements of childhood brain tumors.

Science.gov (United States)

Warren, K E; Patronas, N; Aikin, A A; Albert, P S; Balis, F M

2001-09-19

End points for assessing drug activity in brain tumors are determined by measuring the change in tumor size by magnetic resonance imaging (MRI) relative to a pretreatment or best-response scan. Traditionally, two-dimensional (2D) tumor measurements have been used, but one-dimensional (1D) measurements have recently been proposed as an alternative. Because software to estimate three-dimensional (3D) tumor volume from digitized MRI images is available, we compared all three methods of tumor measurement for childhood brain tumors and clinical outcome. Tumor size from 130 MRI scans from 32 patients (32 baseline and 98 follow-up scans, for a total of 130 scans; median, three scans per patient; range, two to 18 scans) was measured by each method. Tumor-response category (partial response, minor response, stable disease, or progressive disease) was determined from the percentage change in tumor size between the baseline or best-response scan and follow-up scans. Time to clinical progression was independently determined by chart review. All statistical tests were two-sided. Concordances between 1D and 2D, 1D and 3D, and 2D and 3D were 83% (95% confidence interval [CI] = 67% to 99%), 61% (95% CI = 47% to 75%), and 66% (95% CI = 52% to 80%), respectively, on follow-up scans. Concordances for 1D and 3D and for 2D and 3D were statistically significantly lower than the concordance for 1D and 2D (Ptumors in the minor response and progressive-disease categories. Median times to progression measured by the 1D, 2D, and 3D methods were 154, 105, and 112 days, respectively, compared with 114 days based on neurologic symptoms and signs (P = .09 for overall comparison). Detection of partial responses was not influenced by the measurement method, but estimating time to disease progression may be method dependent for childhood brain tumors.

Comparison of one-, two-, and three-dimensional iron phosphates containing ethylenediamine

International Nuclear Information System (INIS)

Song Yanning; Zavalij, Peter Y.; Chernova, Natasha A.; Suzuki, Masatsugu; Whittingham, M.S.

2003-01-01

A new two-dimensional (2d) iron phosphate, (C 2 N 2 H 10 )Fe 2 O(PO 4 ) 2 , has been synthesized under hydrothermal conditions in the system of FeCl 3 -H 3 PO 4 -C 2 N 2 H 8 -H 2 O. The crystal data is: space group P2 1 /c, a=10.670(1) A, b=10.897(1) A, c=9.918(1) A, β=105.632(1) deg. , Z=4. The layered structure consists of double sheet layers, of composition Fe 2 O(PO 4 ) 2 , built from FeO 5 trigonal bipyramids and PO 4 tetrahedra. The amine holds the layers together via H-bonding. The study of the magnetic properties reveals two magnetic transitions at 160 and 30 K with spin-glass-like behavior below 160 K. By varying the hydrothermal conditions, three other iron phosphates were synthesized: the one-dimensional (1d) (C 2 N 2 H 10 )Fe(HPO 4 ) 2 (OH)·H 2 O, the 2d (C 2 N 2 H 10 )Fe 2 (PO 4 ) 2 (OH) 2 , and the three-dimensional (3d) (C 2 N 2 H 10 ) 2 Fe 4 O(PO 4 ) 4 ·H 2 O. The 1d compound can be used as the starting reagent in the synthesis of both the 2d compound and the 3d lipscombite Fe 3 (PO 4 ) 2 (OH) 2 due to the similar building blocks in their structures. In the 3d phosphate (C 2 N 2 H 10 ) 2 Fe 4 O(PO 4 ) 4 ·H 2 O, manganese can substitute for half of the iron atoms. Magnetic study shows ordering transitions at about 30 K, however, manganese substitution depresses the magnetic ordering temperature

Three-dimensional mapping of mechanical activation patterns, contractile dyssynchrony and dyscoordination by two-dimensional strain echocardiography: Rationale and design of a novel software toolbox

Directory of Open Access Journals (Sweden)

Cramer Maarten J

2008-05-01

Full Text Available Abstract Background Dyssynchrony of myocardial deformation is usually described in terms of variability only (e.g. standard deviations SD's. A description in terms of the spatio-temporal distribution pattern (vector-analysis of dyssynchrony or by indices estimating its impact by expressing dyscoordination of shortening in relation to the global ventricular shortening may be preferential. Strain echocardiography by speckle tracking is a new non-invasive, albeit 2-D imaging modality to study myocardial deformation. Methods A post-processing toolbox was designed to incorporate local, speckle tracking-derived deformation data into a 36 segment 3-D model of the left ventricle. Global left ventricular shortening, standard deviations and vectors of timing of shortening were calculated. The impact of dyssynchrony was estimated by comparing the end-systolic values with either early peak values only (early shortening reserve ESR or with all peak values (virtual shortening reserve VSR, and by the internal strain fraction (ISF expressing dyscoordination as the fraction of deformation lost internally due to simultaneous shortening and stretching. These dyssynchrony parameters were compared in 8 volunteers (NL, 8 patients with Wolff-Parkinson-White syndrome (WPW, and 7 patients before (LBBB and after cardiac resynchronization therapy (CRT. Results Dyssynchrony indices merely based on variability failed to detect differences between WPW and NL and failed to demonstrate the effect of CRT. Only the 3-D vector of onset of shortening could distinguish WPW from NL, while at peak shortening and by VSR, ESR and ISF no differences were found. All tested dyssynchrony parameters yielded higher values in LBBB compared to both NL and WPW. CRT reduced the spatial divergence of shortening (both vector magnitude and direction, and improved global ventricular shortening along with reductions in ESR and dyscoordination of shortening expressed by ISF. Conclusion Incorporation

Three-dimensional tori and Arnold tongues

Energy Technology Data Exchange (ETDEWEB)

Sekikawa, Munehisa, E-mail: sekikawa@cc.utsunomiya-u.ac.jp [Department of Mechanical and Intelligent Engineering, Utsunomiya University, Utsunomiya-shi 321-8585 (Japan); Inaba, Naohiko [Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kawasaki-shi 214-8571 (Japan); Kamiyama, Kyohei [Department of Electronics and Bioinformatics, Meiji University, Kawasaki-shi 214-8571 (Japan); Aihara, Kazuyuki [Institute of Industrial Science, the University of Tokyo, Meguro-ku 153-8505 (Japan)

2014-03-15

This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.

Two and three dimensional imaging of compact toroid plasmas using fast photography

International Nuclear Information System (INIS)

Englert, S.E.; Bell, D.E.; Coffey, S.K.

1992-01-01

As is discussed in a companion paper, Degnan el al, fast photography is used as a visual diagnostic tool for high energy plasma research at the Phillips Laboratory. Both, two dimensional and three dimensional images, are gathered by using nanosecond and microsecond range fast photography techniques. A set of microchannel plate cameras and a fast framing camera are used to record images of a compact toroid plasma during formation and acceleration stages. These images are subsequently digitized and enhanced to bring out detailed information of interest. This spatial information is combined with other diagnostic results as well as theoretical models in order to build a more complete picture of the fundamental physics associated with high-energy plasmas

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.

Comparison of two-dimensional and three-dimensional MHD equilibrium and stability codes

International Nuclear Information System (INIS)

Herrnegger, F.; Merkel, P.; Johnson, J.L.

1986-02-01

Stability results obtained with the fully three-dimensional magnetohydrodynamic code BETA, the helically invariant code HERA, and the asymptotic stellarator expansion code STEP agree well for a straight l = 2, M = 5 stellarator model. This good agreement between the BETA and STEP codes persists as toroidal curvature is introduced. This validation provides justification for confidence in work with these models. 20 refs., 11 figs

POST: a postprocessor computer code for producing three-dimensional movies of two-phase flow in a reactor vessel

International Nuclear Information System (INIS)

Taggart, K.A.; Liles, D.R.

1977-08-01

The development of the TRAC computer code for analysis of LOCAs in light-water reactors involves the use of a three-dimensional (r-theta-z), two-fluid hydrodynamics model to describe the two-phase flow of steam and water through the reactor vessel. One of the major problems involved in interpreting results from this code is the presentation of three-dimensional flow patterns. The purpose of the report is to present a partial solution to this data display problem. A first version of a code which produces three-dimensional movies of flow in the reactor vessel has been written and debugged. This code (POST) is used as a postprocessor in conjunction with a stand alone three-dimensional two-phase hydrodynamics code (CYLTF) which is a test bed for the three-dimensional algorithms to be used in TRAC

Three-dimensional microbubble streaming flows

Science.gov (United States)

Rallabandi, Bhargav; Marin, Alvaro; Rossi, Massimiliano; Kaehler, Christian; Hilgenfeldt, Sascha

2014-11-01

Streaming due to acoustically excited bubbles has been used successfully for applications such as size-sorting, trapping and focusing of particles, as well as fluid mixing. Many of these applications involve the precise control of particle trajectories, typically achieved using cylindrical bubbles, which establish planar flows. Using astigmatic particle tracking velocimetry (APTV), we show that, while this two-dimensional picture is a useful description of the flow over short times, a systematic three-dimensional flow structure is evident over long time scales. We demonstrate that this long-time three-dimensional fluid motion can be understood through asymptotic theory, superimposing secondary axial flows (induced by boundary conditions at the device walls) onto the two-dimensional description. This leads to a general framework that describes three-dimensional flows in confined microstreaming systems, guiding the design of applications that profit from minimizing or maximizing these effects.

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.

Evaluating mental workload of two-dimensional and three-dimensional visualization for anatomical structure localization.

Science.gov (United States)

Foo, Jung-Leng; Martinez-Escobar, Marisol; Juhnke, Bethany; Cassidy, Keely; Hisley, Kenneth; Lobe, Thom; Winer, Eliot

2013-01-01

Visualization of medical data in three-dimensional (3D) or two-dimensional (2D) views is a complex area of research. In many fields 3D views are used to understand the shape of an object, and 2D views are used to understand spatial relationships. It is unclear how 2D/3D views play a role in the medical field. Using 3D views can potentially decrease the learning curve experienced with traditional 2D views by providing a whole representation of the patient's anatomy. However, there are challenges with 3D views compared with 2D. This current study expands on a previous study to evaluate the mental workload associated with both 2D and 3D views. Twenty-five first-year medical students were asked to localize three anatomical structures--gallbladder, celiac trunk, and superior mesenteric artery--in either 2D or 3D environments. Accuracy and time were taken as the objective measures for mental workload. The NASA Task Load Index (NASA-TLX) was used as a subjective measure for mental workload. Results showed that participants viewing in 3D had higher localization accuracy and a lower subjective measure of mental workload, specifically, the mental demand component of the NASA-TLX. Results from this study may prove useful for designing curricula in anatomy education and improving training procedures for surgeons.

Backlund transformations and three-dimensional lattice equations

NARCIS (Netherlands)

Nijhoff, F.W.; Capel, H.W.; Wiersma, G.L.; Quispel, G.R.W.

1984-01-01

A (nonlocal) linear integral equation is studied, which allows for Bäcklund transformations in the measure. The compatibility of three of these transformations leads to an integrable nonlinear three-dimensional lattice equation. In appropriate continuum limits the two-dimensional Toda-lattice

Two-dimensional and three-dimensional models used for teaching Human Evolution in Secondary Schools. Learning proficiency assessment. A Case Study

Directory of Open Access Journals (Sweden)

Ulisses Dardon

2016-06-01

Full Text Available The evolution of the human species is a topic of extreme importance reported in the “Parâmetros Curriculares Nacionais do Ensino Médio – PCNEM” (National Curriculum Standards of Secondary Education, although it is not often taught as part of basic education. This work presents the results of an experimental work performed with 31 students of a religious high school of State of Rio de Janeiro. Learning proficiency was assessed by using two-dimensional (2D and three-dimensional (3D illustration techniques of hominids skulls and a Pongidae for teaching Human Evolution. The teaching-learning process using these methodologies was more effective with the application of three-dimensional (3D illustration techniques. The group of students that used 3D illustrations were able to observe similarities and differences between the presented taxonomic models, and formulate hypotheses about their palaeobiology more consistently than the students that used 2D models. Results of this work indicate that the use of three-dimensional techniques (3D provides an excellent support to teaching-learning process in basic education, captivating and stimulating new interests of students during the educational process.

Two-dimensional versus three-dimensional treatment planning of tangential breast irradiation

International Nuclear Information System (INIS)

Damen, E.M.F.; Bruinvis, I.A.D.; Mijnheer, B.J.

1995-01-01

Purpose: Full three-dimensional (3-D) treatment planning requires 3-D patient contours and density information, derived either from CT scanning or from other 3-D contouring methods. These contouring techniques are time consuming, and are often not available or cannot be used. Two-dimensional (2-D) treatment planning can be performed using only a few patient contours, made with much simpler techniques, in combination with simulator images for estimating the lung position. In order to investigate the need for full 3-D planning, we compared the performance of both a 2-D and a 3-D planning system in calculating absolute dose values and relative dose distributions in tangential breast irradiation. Methods: Two breast-shaped phantoms were used in this study. The first phantom consists of a polyethylene mould, filled with water and cork to mimic the lung. An ionization chamber can be inserted in the phantom at fixed positions. The second phantom is made of 25 transverse slices of polystyrene and cork, made with a computerized milling machine from CT information. In this phantom, films can be inserted in three sagittal planes. Both phantoms have been irradiated with two tangential 8 MV photon beams. The measured dose distribution has been compared with the dose distribution predicted by the two planning systems. Results: In the central plane, the 3-D planning system predicts the absolute dose with an accuracy of 0.5 - 4%. The dose at the isocentre of the beams agrees within 0.5% with the measured dose. The 2-D system predicts the dose with an accuracy of 0.9 - 3%. The dose calculated at the isocentre is 2.6% higher than the measured dose, because missing lateral scatter is not taken into account in this planning system. In off-axis planes, the calculated absolute dose agrees with the measured dose within 4% for the 2-D system and within 6% for the 3-D system. However, the relative dose distribution is predicted better by the 3-D planning system. Conclusions: This study

A general theory of two- and three-dimensional rotational flow in subsonic and transonic turbomachines

Science.gov (United States)

Wu, Chung-Hua

1993-01-01

This report represents a general theory applicable to axial, radial, and mixed flow turbomachines operating at subsonic and supersonic speeds with a finite number of blades of finite thickness. References reflect the evolution of computational methods used, from the inception of the theory in the 50's to the high-speed computer era of the 90's. Two kinds of relative stream surfaces, S(sub 1) and S(sub 2), are introduced for the purpose of obtaining a three-dimensional flow solution through the combination of two-dimensional flow solutions. Nonorthogonal curvilinear coordinates are used for the governing equations. Methods of computing transonic flow along S(sub 1) and S(sub 2) stream surfaces are given for special cases as well as for fully three-dimensional transonic flows. Procedures pertaining to the direct solutions and inverse solutions are presented. Information on shock wave locations and shapes needed for computations are discussed. Experimental data from a Deutsche Forschungs- und Versuchsanstalt fur Luft- und Raumfahrt e.V. (DFVLR) rotor and from a Chinese Academy of Sciences (CAS) transonic compressor rotor are compared with the computed flow properties.

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.

[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.

Three dimensional canonical transformations

International Nuclear Information System (INIS)

Tegmen, A.

2010-01-01

A generic construction of canonical transformations is given in three-dimensional phase spaces on which Nambu bracket is imposed. First, the canonical transformations are defined as based on cannonade transformations. Second, it is shown that determination of the generating functions and the transformation itself for given generating function is possible by solving correspondent Pfaffian differential equations. Generating functions of type are introduced and all of them are listed. Infinitesimal canonical transformations are also discussed as the complementary subject. Finally, it is shown that decomposition of canonical transformations is also possible in three-dimensional phase spaces as in the usual two-dimensional ones.

Two-dimensional NMR spectrometry

International Nuclear Information System (INIS)

Farrar, T.C.

1987-01-01

This article is the second in a two-part series. In part one (ANALYTICAL CHEMISTRY, May 15) the authors discussed one-dimensional nuclear magnetic resonance (NMR) spectra and some relatively advanced nuclear spin gymnastics experiments that provide a capability for selective sensitivity enhancements. In this article and overview and some applications of two-dimensional NMR experiments are presented. These powerful experiments are important complements to the one-dimensional experiments. As in the more sophisticated one-dimensional experiments, the two-dimensional experiments involve three distinct time periods: a preparation period, t 0 ; an evolution period, t 1 ; and a detection period, t 2

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.

Three-dimensional particle image velocimetry measurement technique

International Nuclear Information System (INIS)

Hassan, Y.A.; Seeley, C.H.; Henderson, J.A.; Schmidl, W.D.

2004-01-01

The experimental flow visualization tool, Particle Image Velocimetry (PIV), is being used to determine the velocity field in two-dimensional fluid flows. In the past few years, the technique has been improved to allow the capture of flow fields in three dimensions. This paper describes changes which were made to two existing two-dimensional tracking algorithms to enable them to track three-dimensional PIV data. Results of the tests performed on these three-dimensional routines with synthetic data are presented. Experimental data was also used to test the tracking algorithms. The test setup which was used to acquire the three-dimensional experimental data is described, along with the results from both of the tracking routines which were used to analyze the experimental data. (author)

Similarity of the leading contributions to the self-energy and the thermodynamics in two- and three-dimensional Fermi Liquids

International Nuclear Information System (INIS)

Coffey, D.; Bedell, K.S.

1993-01-01

We compare the self-energy and entropy of a two- and three-dimensional Fermi Liquids (FLs) using a model with a contact interaction between fermions. For a two-dimensional (2D) FL we find that there are T 2 contributions to the entropy from interactions separate from those due to the collective modes. These T 2 contributions arise from nonanalytic corrections to the real part of the self-energy and areanalogous to T 3 lnT contributions present in the entropy of a three-dimensional (3D) FL. The difference between the 2D and 3D results arises solely from the different phase space factors

High-resolution two-dimensional and three-dimensional modeling of wire grid polarizers and micropolarizer arrays

Science.gov (United States)

Vorobiev, Dmitry; Ninkov, Zoran

2017-11-01

Recent advances in photolithography allowed the fabrication of high-quality wire grid polarizers for the visible and near-infrared regimes. In turn, micropolarizer arrays (MPAs) based on wire grid polarizers have been developed and used to construct compact, versatile imaging polarimeters. However, the contrast and throughput of these polarimeters are significantly worse than one might expect based on the performance of large area wire grid polarizers or MPAs, alone. We investigate the parameters that affect the performance of wire grid polarizers and MPAs, using high-resolution two-dimensional and three-dimensional (3-D) finite-difference time-domain simulations. We pay special attention to numerical errors and other challenges that arise in models of these and other subwavelength optical devices. Our tests show that simulations of these structures in the visible and near-IR begin to converge numerically when the mesh size is smaller than ˜4 nm. The performance of wire grid polarizers is very sensitive to the shape, spacing, and conductivity of the metal wires. Using 3-D simulations of micropolarizer "superpixels," we directly study the cross talk due to diffraction at the edges of each micropolarizer, which decreases the contrast of MPAs to ˜200∶1.

A Semi-implicit Numerical Scheme for a Two-dimensional, Three-field Thermo-Hydraulic Modeling

International Nuclear Information System (INIS)

Hwang, Moonkyu; Jeong, Jaejoon

2007-07-01

The behavior of two-phase flow is modeled, depending on the purpose, by either homogeneous model, drift flux model, or separated flow model, Among these model, in the separated flow model, the behavior of each flow phase is modeled by its own governing equation, together with the interphase models which describe the thermal and mechanical interactions between the phases involved. In this study, a semi-implicit numerical scheme for two-dimensional, transient, two-fluid, three-field is derived. The work is an extension to the previous study for the staggered, semi-implicit numerical scheme in one-dimensional geometry (KAERI/TR-3239/2006). The two-dimensional extension is performed by specifying a relevant governing equation set and applying the related finite differencing method. The procedure for employing the semi-implicit scheme is also described in detail. Verifications are performed for a 2-dimensional vertical plate for a single-phase and two-phase flows. The calculations verify the mass and energy conservations. The symmetric flow behavior, for the verification problem, also confirms the momentum conservation of the numerical scheme

Mechanisms of Pyroelectricity in Three- and Two-Dimensional Materials

Science.gov (United States)

Liu, Jian; Pantelides, Sokrates T.

2018-05-01

Pyroelectricity is a very promising phenomenon in three- and two-dimensional materials, but first-principles calculations have not so far been used to elucidate the underlying mechanisms. Here we report density-functional theory (DFT) calculations based on the Born-Szigeti theory of pyroelectricity, by combining fundamental thermodynamics and the modern theory of polarization. We find satisfactory agreement with experimental data in the case of bulk benchmark materials, showing that the so-called electron-phonon renormalization, whose contribution has been traditionally viewed as negligible, is important. We predict out-of-plane pyroelectricity in the recently synthesized Janus MoSSe monolayer and in-plane pyroelectricity in the group-IV monochalcogenide GeS monolayer. It is notable that the so-called secondary pyroelectricity is found to be dominant in GeS monolayer. The present work opens a theoretical route to study the pyroelectric effect using DFT and provides a valuable tool in the search for new candidates for pyroelectric applications.

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.

Regularized lattice Bhatnagar-Gross-Krook model for two- and three-dimensional cavity flow simulations.

Science.gov (United States)

Montessori, A; Falcucci, G; Prestininzi, P; La Rocca, M; Succi, S

2014-05-01

We investigate the accuracy and performance of the regularized version of the single-relaxation-time lattice Boltzmann equation for the case of two- and three-dimensional lid-driven cavities. The regularized version is shown to provide a significant gain in stability over the standard single-relaxation time, at a moderate computational overhead.

Forming three-dimensional closed shapes from two-dimensional soft ribbons by controlled buckling

Science.gov (United States)

Aoki, Michio; Juang, Jia-Yang

2018-02-01

Conventional manufacturing techniques-moulding, machining and casting-exist to produce three-dimensional (3D) shapes. However, these industrial processes are typically geared for mass production and are not directly applicable to residential settings, where inexpensive and versatile tools are desirable. Moreover, those techniques are, in general, not adequate to process soft elastic materials. Here, we introduce a new concept of forming 3D closed hollow shapes from two-dimensional (2D) elastic ribbons by controlled buckling. We numerically and experimentally characterize how the profile and thickness of the ribbon determine its buckled shape. We find a 2D master profile with which various elliptical 3D shapes can be formed. More complex natural and artificial hollow shapes, such as strawberry, hourglass and wheel, can also be achieved via strategic design and pattern engraving on the ribbons. The nonlinear response of the post-buckling regime is rationalized through finite-element analysis, which shows good quantitative agreement with experiments. This robust fabrication should complement conventional techniques and provide a rich arena for future studies on the mechanics and new applications of elastic hollow structures.

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

Simulation on three dimensional bubble formation using MARS

International Nuclear Information System (INIS)

Kunugi, Tomoaki

1997-01-01

This paper describes a numerical simulation on three-dimensional bubble formation by means of the MARS (Multi-interfaces Advection and Reconstruction Solver) developed by the author. The comparison between two-dimensional and three-dimensional simulation on an agglomeration of two bubbles is discussed. Moreover, some simulation results regarding a phase change phenomena such as a boiling and condensation in a two dimensional enclosure with heated and cooled walls are presented. (author)

Quantum transport of atomic matter waves in anisotropic two-dimensional and three-dimensional disorder

International Nuclear Information System (INIS)

Piraud, M; Pezzé, L; Sanchez-Palencia, L

2013-01-01

The macroscopic transport properties in a disordered potential, namely diffusion and weak/strong localization, closely depend on the microscopic and statistical properties of the disorder itself. This dependence is rich in counter-intuitive consequences. It can be particularly exploited in matter wave experiments, where the disordered potential can be tailored and controlled, and anisotropies are naturally present. In this work, we apply a perturbative microscopic transport theory and the self-consistent theory of Anderson localization to study the transport properties of ultracold atoms in anisotropic two-dimensional (2D) and three-dimensional (3D) speckle potentials. In particular, we discuss the anisotropy of single-scattering, diffusion and localization. We also calculate disorder-induced shift of the energy states and propose a method to include it, which amounts to renormalizing energies in the standard on-shell approximation. We show that the renormalization of energies strongly affects the prediction for the 3D localization threshold (mobility edge). We illustrate the theoretical findings with examples which are relevant for current matter wave experiments, where the disorder is created with laser speckle. This paper provides a guideline for future experiments aiming at the precise location of the 3D mobility edge and study of anisotropic diffusion and localization effects in 2D and 3D. (paper)

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.

Ring-shaped quasi-soliton solutions to the two-and three-dimensional Sine-Gordon equation

International Nuclear Information System (INIS)

Christiansen, P.L.; Olsen, O.H.

1979-01-01

Ring-shaped solitary wave solutions to the Sine-Gordon equation in two and three spatial dimensions are investigated by numerical computation. Each expanding wave exhibits a return effect. The reflection of the shrinking wave at the singularity at the center of the wave is investigated in a particular case. Collision experiments in numero for expanding and shrinking concentric ring waves show that the solutions possess quasisoliton properties. A Baecklund transformation for the non-symmetric three-dimensional case is given. (Auth.)

The Two- and Three-Dimensional Models of the HK-WISC: A Confirmatory Factor Analysis.

Science.gov (United States)

Chan, David W.; Lin, Wen-Ying

1996-01-01

Confirmatory analyses on the Hong Kong Wechsler Intelligence Scale for Children (HK-WISC) provided support for composite score interpretation based on the two- and three-dimensional models across age levels. Test sample was comprised of 1,100 children, ranging in age from 5 to 15 years at all 11 age levels specified by the HK-WISC. (KW)

Microstructure in two- and three-dimensional hybrid simulations of perpendicular collisionless shocks

Czech Academy of Sciences Publication Activity Database

Burgess, D.; Hellinger, Petr; Gingell, I.; Trávníček, Pavel M.

2016-01-01

Roč. 82, č. 4 (2016), 905820401/1-905820401/23 ISSN 0022-3778 Institutional support: RVO:68378289 Keywords : ion-acceleration * numerical simulations * bow shock * electron acceleration * cluster observations * self-reformation * magnetic-field * whistler waves * injection * nonstationarity Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.160, year: 2016 https://www.cambridge.org/core/ journals /journal-of-plasma-physics/article/microstructure-in-two-and-three-dimensional-hybrid-simulations-of-perpendicular-collisionless-shocks/F964EF89FB14A6504A49CFAD54970E2B

GAMMA-RAY BURST LUMINOSITY RELATIONS: TWO-DIMENSIONAL VERSUS THREE-DIMENSIONAL CORRELATIONS

International Nuclear Information System (INIS)

Yu Bo; Qi Shi; Lu Tan

2009-01-01

The large scatters of luminosity relations of gamma-ray bursts (GRBs) have been one of the most important reasons that prevent the extensive applications of GRBs in cosmology. In this paper, we extend the two-dimensional (2D) luminosity relations with τ lag , V, E peak , and τ RT as the luminosity indicators to three dimensions (3D) using the same set of luminosity indicators to explore the possibility of decreasing the intrinsic scatters. We find that, for the 3D luminosity relations between the luminosity and an energy scale (E peak ) and a timescale (τ lag or τ RT ), their intrinsic scatters are considerably smaller than those of corresponding 2D luminosity relations. Enlightened by the result and the definition of the luminosity (energy released in units of time), we discussed possible reasons behind this result, which may give us helpful suggestions on seeking more precise luminosity relations for GRBs in the future.

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

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)

Role of cardiac imaging and three-dimensional printing in percutaneous appendage closure.

Science.gov (United States)

Iriart, Xavier; Ciobotaru, Vlad; Martin, Claire; Cochet, Hubert; Jalal, Zakaria; Thambo, Jean-Benoit; Quessard, Astrid

2018-06-06

Atrial fibrillation is the most frequent cardiac arrhythmia, affecting up to 13% of people aged>80 years, and is responsible for 15-20% of all ischaemic strokes. Left atrial appendage occlusion devices have been developed as an alternative approach to reduce the risk of stroke in patients for whom oral anticoagulation is contraindicated. The procedure can be technically demanding, and obtaining a complete left atrial appendage occlusion can be challenging. These observations have emphasized the importance of preprocedural planning, to optimize the accuracy and safety of the procedure. In this setting, a multimodality imaging approach, including three-dimensional imaging, is often used for preoperative assessment and procedural guidance. These imaging modalities, including transoesophageal echocardiography and multislice computed tomography, allow acquisition of a three-dimensional dataset that improves understanding of the cardiac anatomy; dedicated postprocessing software integrated into the clinical workflow can be used to generate a stereolithography file, which can be printed in a rubber-like material, seeking to replicate the myocardial tissue characteristics and mechanical properties of the left atrial appendage wall. The role of multimodality imaging and 3D printing technology offers a new field for implantation simulation, which may have a major impact on physician training and technique optimization. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Three-dimensional instability of standing waves

Science.gov (United States)

Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

2003-12-01

We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

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)

Three-dimensional numerical modeling of turbulent single-phase and two-phase flow in curved pipes

International Nuclear Information System (INIS)

Xin, R.C.; Dong, Z.F.; Ebadian, M.A.

1996-01-01

In this study, three-dimensional single-phase and two-phase flows in curved pipes have been investigated numerically. Two different pipe configurations were computed. When the results of the single-phase flow simulation were compared with the experimental data, a fairly good agreement was achieved. A flow-developing process has been suggested in single-phase flow, in which the turbulence is stronger near the outer tube wall than near the inner tube wall. For two-phase flow, the Eulerian multiphase model was used to simulate the phase distribution of a three-dimensional gas-liquid bubble flow in curved pipe. The RNG/κ-ε turbulence model was used to determine the turbulence field. An inlet gas void fraction of 5 percent was simulated. The gas phase effects on the liquid phase flow velocity have been examined by comparing the results of single-phase flow and two-phase flow. The findings show that for the downward flow in the U bend, the gas concentrates at the inner portion of the cross section at φ = π/18 - π/6 in most cases. The results of the phase distribution simulation are compared to experimental observations qualitatively and topologically

Interaction Deep Excavation Adjacent Structure Numerical Two and Three Dimensional Modeling

International Nuclear Information System (INIS)

Abdallah, M.; Chehade, F. H.; Chehade, W.; Fawaz, A.

2011-01-01

Urban development often requires the construction of deep excavations near to buildings or other structures. We have to study complex material structure interactions where we should take into consideration several particularities. In this paper, we perform a numerical modeling with the finite element method, using PLAXIS software, of the interaction deep excavation-diaphragm wall-soil-structure in the case of non linear soil behavior. We focus our study on a comparison of the results given respectively by two and three dimensional modelings. This allows us to give some recommendations concerning the validity of twodimensional study. We perform a parametric study according to the initial loading on the structure and the struts number. (author)

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

Directory of Open Access Journals (Sweden)

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.

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

Science.gov (United States)

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.

Intraoperative application of geometric three-dimensional mitral valve assessment package: a feasibility study.

Science.gov (United States)

Mahmood, Feroze; Karthik, Swaminathan; Subramaniam, Balachundhar; Panzica, Peter J; Mitchell, John; Lerner, Adam B; Jervis, Karinne; Maslow, Andrew D

2008-04-01

To study the feasibility of using 3-dimensional (3D) echocardiography in the operating room for mitral valve repair or replacement surgery. To perform geometric analysis of the mitral valve before and after repair. Prospective observational study. Academic, tertiary care hospital. Consecutive patients scheduled for mitral valve surgery. Intraoperative reconstruction of 3D images of the mitral valve. One hundred and two patients had 3D analysis of their mitral valve. Successful image reconstruction was performed in 93 patients-8 patients had arrhythmias or a dilated mitral valve annulus resulting in significant artifacts. Time from acquisition to reconstruction and analysis was less than 5 minutes. Surgeon identification of mitral valve anatomy was 100% accurate. The study confirms the feasibility of performing intraoperative 3D reconstruction of the mitral valve. This data can be used for confirmation and communication of 2-dimensional data to the surgeons by obtaining a surgical view of the mitral valve. The incorporation of color-flow Doppler into these 3D images helps in identification of the commissural or perivalvular location of regurgitant orifice. With improvements in the processing power of the current generation of echocardiography equipment, it is possible to quickly acquire, reconstruct, and manipulate images to help with timely diagnosis and surgical planning.

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

Standalone visualization tool for three-dimensional DRAGON geometrical models

International Nuclear Information System (INIS)

Lukomski, A.; McIntee, B.; Moule, D.; Nichita, E.

2008-01-01

DRAGON is a neutron transport and depletion code able to solve one-, two- and three-dimensional problems. To date DRAGON provides two visualization modules, able to represent respectively two- and three-dimensional geometries. The two-dimensional visualization module generates a postscript file, while the three dimensional visualization module generates a MATLAB M-file with instructions for drawing the tracks in the DRAGON TRACKING data structure, which implicitly provide a representation of the geometry. The current work introduces a new, standalone, tool based on the open-source Visualization Toolkit (VTK) software package which allows the visualization of three-dimensional geometrical models by reading the DRAGON GEOMETRY data structure and generating an axonometric image which can be manipulated interactively by the user. (author)

Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise

International Nuclear Information System (INIS)

Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

2012-01-01

A new algorithm is developed for reconstructing the high-resolution three-dimensional diffraction intensity function of a globular biological macromolecule from many quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The structural resolution is expressed as a function of the incident X-ray intensity and quantities characterizing the target molecule. A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ∼0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule

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.

Advanced numerical methods for three dimensional two-phase flow calculations in PWR

International Nuclear Information System (INIS)

Toumi, I.; Gallo, D.; Royer, E.

1997-01-01

This paper is devoted to new numerical methods developed for three dimensional two-phase flow calculations. These methods are finite volume numerical methods. They are based on an extension of Roe's approximate Riemann solver to define convective fluxes versus mean cell quantities. To go forward in time, a linearized conservative implicit integrating step is used, together with a Newton iterative method. We also present here some improvements performed to obtain a fully implicit solution method that provides fast running steady state calculations. This kind of numerical method, which is widely used for fluid dynamic calculations, is proved to be very efficient for the numerical solution to two-phase flow problems. This numerical method has been implemented for the three dimensional thermal-hydraulic code FLICA-4 which is mainly dedicated to core thermal-hydraulic transient and steady-state analysis. Hereafter, we will also find some results obtained for the EPR reactor running in a steady-state at 60% of nominal power with 3 pumps out of 4, and a thermal-hydraulic core analysis for a 1300 MW PWR at low flow steam-line-break conditions. (author)

Automatic two- and three-dimensional mesh generation based on fuzzy knowledge processing

Science.gov (United States)

Yagawa, G.; Yoshimura, S.; Soneda, N.; Nakao, K.

1992-09-01

This paper describes the development of a novel automatic FEM mesh generation algorithm based on the fuzzy knowledge processing technique. A number of local nodal patterns are stored in a nodal pattern database of the mesh generation system. These nodal patterns are determined a priori based on certain theories or past experience of experts of FEM analyses. For example, such human experts can determine certain nodal patterns suitable for stress concentration analyses of cracks, corners, holes and so on. Each nodal pattern possesses a membership function and a procedure of node placement according to this function. In the cases of the nodal patterns for stress concentration regions, the membership function which is utilized in the fuzzy knowledge processing has two meanings, i.e. the “closeness” of nodal location to each stress concentration field as well as “nodal density”. This is attributed to the fact that a denser nodal pattern is required near a stress concentration field. What a user has to do in a practical mesh generation process are to choose several local nodal patterns properly and to designate the maximum nodal density of each pattern. After those simple operations by the user, the system places the chosen nodal patterns automatically in an analysis domain and on its boundary, and connects them smoothly by the fuzzy knowledge processing technique. Then triangular or tetrahedral elements are generated by means of the advancing front method. The key issue of the present algorithm is an easy control of complex two- or three-dimensional nodal density distribution by means of the fuzzy knowledge processing technique. To demonstrate fundamental performances of the present algorithm, a prototype system was constructed with one of object-oriented languages, Smalltalk-80 on a 32-bit microcomputer, Macintosh II. The mesh generation of several two- and three-dimensional domains with cracks, holes and junctions was presented as examples.

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

Three-Dimensional Target Localization and Cramér-Rao Bound for Two-Dimensional OFDM-MIMO Radar

Directory of Open Access Journals (Sweden)

Xingxing Li

2017-01-01

Full Text Available Target localization using a frequency diversity multiple-input multiple-output (MIMO system is one of the hottest research directions in the radar society. In this paper, three-dimensional (3D target localization is considered for two-dimensional MIMO radar with orthogonal frequency division multiplexing linear frequency modulated (OFDM-LFM waveforms. To realize joint estimation for range and angle in azimuth and elevation, the range-angle-dependent beam pattern with high range resolution is produced by the OFDM-LFM waveform. Then, the 3D target localization proposal is presented and the corresponding closed-form expressions of Cramér-Rao bound (CRB are derived. Furthermore, for mitigating the coupling of angle and range and further improving the estimation precision, a CRB optimization method is proposed. Different from the existing methods of FDA-based radar, the proposed method can provide higher range estimation because of multiple transmitted frequency bands. Numerical simulation results are provided to demonstrate the effectiveness of the proposed approach and its improved performance of target localization.

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.

Two-dimensional metamaterial optics

International Nuclear Information System (INIS)

Smolyaninov, I I

2010-01-01

While three-dimensional photonic metamaterials are difficult to fabricate, many new concepts and ideas in the metamaterial optics can be realized in two spatial dimensions using planar optics of surface plasmon polaritons. In this paper we review recent progress in this direction. Two-dimensional photonic crystals, hyperbolic metamaterials, and plasmonic focusing devices are demonstrated and used in novel microscopy and waveguiding schemes

Three Dimensional Dirac Semimetals

Science.gov (United States)

Zaheer, Saad

2014-03-01

Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.

The Effects of Modafinil and Ove-the-Counter Stimulants on Two- and Three- Dimensional Visual Localization

Science.gov (United States)

2017-12-19

AFRL-SA-WP-SR-2017-0029 The Effects of Modafinil and Over-the-Counter Stimulants on Two- and Three- Dimensional Visual Localization...per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...Report 3. DATES COVERED (From – To) June 2012 – May 2015 4. TITLE AND SUBTITLE The Effects of Modafinil and Over-the-Counter Stimulants on Two- and

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....

Differentiation of benign from malignant solid breast masses: comparison of two-dimensional and three-dimensional shear-wave elastography.

Science.gov (United States)

Lee, Su Hyun; Chang, Jung Min; Kim, Won Hwa; Bae, Min Sun; Cho, Nariya; Yi, Ann; Koo, Hye Ryoung; Kim, Seung Ja; Kim, Jin You; Moon, Woo Kyung

2013-04-01

To prospectively compare the diagnostic performances of two-dimensional (2D) and three-dimensional (3D) shear-wave elastography (SWE) for differentiating benign from malignant breast masses. B-mode ultrasound and SWE were performed for 134 consecutive women with 144 breast masses before biopsy. Quantitative elasticity values (maximum and mean elasticity in the stiffest portion of mass, Emax and Emean; lesion-to-fat elasticity ratio, Erat) were measured with both 2D and 3D SWE. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity of B-mode, 2D, 3D SWE and combined data of B-mode and SWE were compared. Sixty-seven of the 144 breast masses (47 %) were malignant. Overall, higher elasticity values of 3D SWE than 2D SWE were noted for both benign and malignant masses. The AUC for 2D and 3D SWE were not significantly different: Emean, 0.938 vs 0.928; Emax, 0.939 vs 0.930; Erat, 0.907 vs 0.871. Either 2D or 3D SWE significantly improved the specificity of B-mode ultrasound from 29.9 % (23 of 77) up to 71.4 % (55 of 77) and 63.6 % (49 of 77) without a significant change in sensitivity. Two-dimensional and 3D SWE performed equally in distinguishing benign from malignant masses and both techniques improved the specificity of B-mode ultrasound.

Three-dimensional reconstruction and visualization system for medical images

International Nuclear Information System (INIS)

Preston, D.F.; Batnitzky, S.; Kyo Rak Lee; Cook, P.N.; Cook, L.T.; Dwyer, S.J.

1982-01-01

A three-dimensional reconstruction and visualization system could be of significant advantage in medical application such as neurosurgery and radiation treatment planning. The reconstructed anatomic structures from CT head scans could be used in a head stereotactic system to help plan the surgical procedure and the radiation treatment for a brain lesion. Also, the use of three-dimensional reconstruction algorithm provides for quantitative measures such as volume and surface area estimation of the anatomic features. This aspect of the three-dimensional reconstruction system may be used to monitor the progress or staging of a disease and the effects of patient treatment. Two cases are presented to illustrate the three-dimensional surface reconstruction and visualization system

Arching in three-dimensional clogging

Science.gov (United States)

Török, János; Lévay, Sára; Szabó, Balázs; Somfai, Ellák; Wegner, Sandra; Stannarius, Ralf; Börzsönyi, Tamás

2017-06-01

Arching in dry granular material is a long established concept, however it remains still an open question how three-dimensional orifices clog. We investigate by means of numerical simulations and experimental data how the outflow creates a blocked configuration of particles. We define the concave surface of the clogged dome by two independent methods (geometric and density based). The average shape of the cupola for spheres is almost a hemisphere but individual samples have large holes in the structure indicating a blocked state composed of two-dimensional force chains rather than three-dimensional objects. The force chain structure justifies this assumption. For long particles the clogged configurations display large variations, and in certain cases the empty region reaches a height of 5 hole diameters. These structures involve vertical walls consisting of horizontally placed stable stacking of particles.

Phonon-assisted damping of plasmons in three- and two-dimensional metals

Science.gov (United States)

Caruso, Fabio; Novko, Dino; Draxl, Claudia

2018-05-01

We investigate the effects of crystal lattice vibrations on the dispersion of plasmons. The loss function of the homogeneous electron gas (HEG) in two and three dimensions is evaluated numerically in the presence of electronic coupling to an optical phonon mode. Our calculations are based on many-body perturbation theory for the dielectric function as formulated by the Hedin-Baym equations in the Fan-Migdal approximation. The coupling to phonons broadens the spectral signatures of plasmons in the electron-energy loss spectrum (EELS) and it induces the decay of plasmons on timescales shorter than 1 ps. Our results further reveal the formation of a kink in the plasmon dispersion of the two-dimensional HEG, which marks the onset of plasmon-phonon scattering. Overall, these features constitute a fingerprint of plasmon-phonon coupling in EELS of simple metals. It is shown that these effects may be accounted for by resorting to a simplified treatment of the electron-phonon interaction which is amenable to first-principles calculations.

Two-dimensional and three-dimensional ultrasonography for pregnancy diagnosis and antenatal fetal development in Beetal goats

Directory of Open Access Journals (Sweden)

Kailash Kumar

2015-07-01

Full Text Available Aim: The objective of this study was to compare two-dimensional (2D and three-dimensional (3D study of the pregnant uterus and antenatal development of the fetus. Materials and Methods: 2D and 3D ultrasound were performed from day 20 to 120 of gestation, twice in week from day 20 to 60 and once in week from day 60 to 120 of gestation on six goats. The ultrasonographic images were obtained using Toshiba, Nemio-XG (Japan 3D ultrasound machine. Results: On the 20th day of gestation, earliest diagnosis of pregnancy was done. First 3D ultrasonographic image of the conceptus, through transabdominal approach, was obtained on day 24. On 39th day, clear pictures of conceptus, amniotic membrane, and umbilicus were seen. On 76th day of gestation, internal organs of fetus viz heart, kidney, liver, urinary bladder, and stomach were seen both in 2D and 3D images. 3D imaging showed better details of uterine structures and internal organs of the fetus. Conclusions: Comparing 3D images with 2D images, it is concluded that 2D was better in visualizing fluid while 3D images were better to view details of attachment of fetus with endometrium.

Point interactions in two- and three-dimensional Riemannian manifolds

International Nuclear Information System (INIS)

Erman, Fatih; Turgut, O Teoman

2010-01-01

We present a non-perturbative renormalization of the bound state problem of n bosons interacting with finitely many Dirac-delta interactions on two- and three-dimensional Riemannian manifolds using the heat kernel. We formulate the problem in terms of a new operator called the principal or characteristic operator Φ(E). In order to investigate the problem in more detail, we then restrict the problem to one particle sector. The lower bound of the ground state energy is found for a general class of manifolds, e.g. for compact and Cartan-Hadamard manifolds. The estimate of the bound state energies in the tunneling regime is calculated by perturbation theory. Non-degeneracy and uniqueness of the ground state is proven by the Perron-Frobenius theorem. Moreover, the pointwise bounds on the wave function is given and all these results are consistent with the one given in standard quantum mechanics. Renormalization procedure does not lead to any radical change in these cases. Finally, renormalization group equations are derived and the β function is exactly calculated. This work is a natural continuation of our previous work based on a novel approach to the renormalization of point interactions, developed by Rajeev.

Speckle reduction in echocardiography by temporal compounding and anisotropic diffusion filtering

Science.gov (United States)

Giraldo-Guzmán, Jader; Porto-Solano, Oscar; Cadena-Bonfanti, Alberto; Contreras-Ortiz, Sonia H.

2015-01-01

Echocardiography is a medical imaging technique based on ultrasound signals that is used to evaluate heart anatomy and physiology. Echocardiographic images are affected by speckle, a type of multiplicative noise that obscures details of the structures, and reduces the overall image quality. This paper shows an approach to enhance echocardiography using two processing techniques: temporal compounding and anisotropic diffusion filtering. We used twenty echocardiographic videos that include one or three cardiac cycles to test the algorithms. Two images from each cycle were aligned in space and averaged to obtain the compound images. These images were then processed using anisotropic diffusion filters to further improve their quality. Resultant images were evaluated using quality metrics and visual assessment by two medical doctors. The average total improvement on signal-to-noise ratio was up to 100.29% for videos with three cycles, and up to 32.57% for videos with one cycle.

Continuum modeling of three-dimensional truss-like space structures

Science.gov (United States)

Nayfeh, A. H.; Hefzy, M. S.

1978-01-01

A mathematical and computational analysis capability has been developed for calculating the effective mechanical properties of three-dimensional periodic truss-like structures. Two models are studied in detail. The first, called the octetruss model, is a three-dimensional extension of a two-dimensional model, and the second is a cubic model. Symmetry considerations are employed as a first step to show that the specific octetruss model has four independent constants and that the cubic model has two. The actual values of these constants are determined by averaging the contributions of each rod element to the overall structure stiffness. The individual rod member contribution to the overall stiffness is obtained by a three-dimensional coordinate transformation. The analysis shows that the effective three-dimensional elastic properties of both models are relatively close to each other.

Two- and three-dimensional accuracy of dental impression materials: effects of storage time and moisture contamination.

Science.gov (United States)

Chandran, Deepa T; Jagger, Daryll C; Jagger, Robert G; Barbour, Michele E

2010-01-01

Dental impression materials are used to create an inverse replica of the dental hard and soft tissues, and are used in processes such as the fabrication of crowns and bridges. The accuracy and dimensional stability of impression materials are of paramount importance to the accuracy of fit of the resultant prosthesis. Conventional methods for assessing the dimensional stability of impression materials are two-dimensional (2D), and assess shrinkage or expansion between selected fixed points on the impression. In this study, dimensional changes in four impression materials were assessed using an established 2D and an experimental three-dimensional (3D) technique. The former involved measurement of the distance between reference points on the impression; the latter a contact scanning method for producing a computer map of the impression surface showing localised expansion, contraction and warpage. Dimensional changes were assessed as a function of storage times and moisture contamination comparable to that found in clinical situations. It was evident that dimensional changes observed using the 3D technique were not always apparent using the 2D technique, and that the former offers certain advantages in terms of assessing dimensional accuracy and predictability of impression methods. There are, however, drawbacks associated with 3D techniques such as the more time-consuming nature of the data acquisition and difficulty in statistically analysing the data.

Vibrational spectra and thermal rectification in three-dimensional anharmonic lattices

International Nuclear Information System (INIS)

Lan Jinghua; Li Baowen

2007-01-01

We study thermal rectification in a three-dimensional model consisting of two segments of anharmonic lattices. One segment consists of layers of harmonic oscillator arrays coupled to a substrate potential, which is a three-dimensional Frenkel-Kontorova model, and the other segment is a three-dimensional Fermi-Pasta-Ulam model. We study the vibrational bands of the two lattices analytically and numerically, and find that, by choosing the system parameters properly, the rectification can be as high as a few thousands, which is high enough to be observed in experiment. Possible experiments in nanostructures are discussed

Two- and three-dimensional cadmium-organic frameworks with trimesic acid and 4,4'-trimethylenedipyridine.

Science.gov (United States)

Almeida Paz, Filipe A; Klinowski, Jacek

2004-06-28

Three novel cadmium-organic frameworks built-up from 1,3,5-benzenetricarboxylate anions (HXBTC(x-3)) and 4,4'-trimethylenedipyridine (TMD) have been hydrothermally synthesized, and characterized using single-crystal X-ray diffraction, thermoanalytical measurements, elemental analysis, and IR and Raman spectroscopies: [Cd(HBTC)(TMD)(2)].8.5H(2)O (I), [Cd(HBTC)(TMD)(H(2)O)].4.5H(2)O (II), and [Cd(2)(BTC)(TMD)(2)(NO(3))].3H(2)O (III), with structures I and II being isolated as a mixture of crystals. Structure I contains an undulating infinite two-dimensional [Cd(HBTC)(TMD)(2)] framework, with a (4,4) topology and rectangular pores, ca. 3.4 x 11.0 A in cross-section, distributed in a herringbone manner. The crystal structure of I is obtained by parallel packing of this 2D framework in an [ABAB.] fashion. Compound II has a porous 3D diamondoid framework with channels running in several directions of the unit cell, which allows 2-fold interpenetration to occur. The most prominent channels are distributed in a brick-wall fashion along the c axis and have a cross-section of ca. 3.2 x 13.2 A. Structure III can be seen as the three-dimensional assembly of binuclear secondary building units (SBU), which leads to a compact, neutral, and coordinatively bonded eight-connected framework, [Cd(2)(BTC)(TMD)(2)(NO(3))], exhibiting an unusual 3(6)4(22) topology. The increased flexibility of the TMD ligands (brought about by the three methylene groups between the two 4-pyridyl rings) can lead, for the same reactive system, to a large variety of crystal architectures.

Three-dimensional simulations in optimal performance trial between two types of Hall sensors fabrication technologies

Energy Technology Data Exchange (ETDEWEB)

Paun, Maria-Alexandra, E-mail: map65@cam.ac.uk

2015-10-01

The main objective of the present work is to make a comparison between Hall devices integrated in regular bulk and Silicon-on-Insulator (SOI) CMOS technology. A three-dimensional model based on numerical estimation is provided for a particular XL Hall structure in two different technologies (the first one is XFAB XH 0.35 µm regular bulk CMOS and the second one is XFAB SOI XI10 1 µm non-fully depleted). In assessing the performance of the Hall Effect sensors included in the comparison, both three-dimensional physical simulations and measurements results will be used. In order to discriminate which category of sensors has the highest performance, their main characteristic parameters, including input resistance, Hall voltage, absolute sensitivity and their temperature drift, will be extracted and compared. Electrostatic potential and current density distribution are important aspects that are also investigated. The particular technology offering the highest sensor performance is identified. - Highlights: • A comparison between Hall devices integrated in regular bulk and SOI CMOS technologies is made. • A three-dimensional model for the XL Hall structure, in the two technologies, is provided. • The main characteristic parameters and the temperature drift are investigated. • The sensors performance is evaluated using 3D physical simulations and measurements data.

Three-dimensional fluorescence lifetime tomography

International Nuclear Information System (INIS)

Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

2005-01-01

Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores

Static and dynamic properties of three-dimensional dot-type magnonic crystals

International Nuclear Information System (INIS)

Maksymov, Artur; Spinu, Leonard

2016-01-01

The static and dynamic magnetization of three-dimensional magnonic metamaterials has been investigated. By numerical means it was analyzed the impact of space dimensionality on the properties of magnonic crystal with unit cell consisting of four dots. It is find out the possibility of multi-vortex core formation which is related to the increasing of the crystal height by three-dimensional periodicity of single crystal layer. Additionally is provided the analysis of ferromagnetic resonance phenomenon for two-dimensional and three-dimensional structures. For the unsaturated magnetization of three-dimensional crystal the several pronounced resonance frequencies were detected.

Static and dynamic properties of three-dimensional dot-type magnonic crystals

Energy Technology Data Exchange (ETDEWEB)

Maksymov, Artur, E-mail: maxyartur@gmail.com [Advanced Materials Research Institute, University of New Orleans, LA 70148 (United States); Department of General Physics, Chernivtsi National University, Chernivtsi 58012 (Ukraine); Spinu, Leonard [Advanced Materials Research Institute, University of New Orleans, LA 70148 (United States); Department of Physics, University of New Orleans, New Orleans, LA 70148 (United States)

2016-04-01

The static and dynamic magnetization of three-dimensional magnonic metamaterials has been investigated. By numerical means it was analyzed the impact of space dimensionality on the properties of magnonic crystal with unit cell consisting of four dots. It is find out the possibility of multi-vortex core formation which is related to the increasing of the crystal height by three-dimensional periodicity of single crystal layer. Additionally is provided the analysis of ferromagnetic resonance phenomenon for two-dimensional and three-dimensional structures. For the unsaturated magnetization of three-dimensional crystal the several pronounced resonance frequencies were detected.

Research and Realization of Medical Image Fusion Based on Three-Dimensional Reconstruction

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

A new medical image fusion technique is presented. The method is based on three-dimensional reconstruction. After reconstruction, the three-dimensional volume data is normalized by three-dimensional coordinate conversion in the same way and intercepted through setting up cutting plane including anatomical structure, as a result two images in entire registration on space and geometry are obtained and the images are fused at last.Compared with traditional two-dimensional fusion technique, three-dimensional fusion technique can not only resolve the different problems existed in the two kinds of images, but also avoid the registration error of the two kinds of images when they have different scan and imaging parameter. The research proves this fusion technique is more exact and has no registration, so it is more adapt to arbitrary medical image fusion with different equipments.

Two-dimensional mapping of three-dimensional SPECT data: a preliminary step to the quantitation of thallium myocardial perfusion single photon emission tomography

International Nuclear Information System (INIS)

Goris, M.L.; Boudier, S.; Briandet, P.A.

1987-01-01

A method is presented by which tomographic myocardial perfusion data are prepared for quantitative analysis. The method is characterized by an interrogation of the original data, which results in a size and shape normalization. The method is analogous to the circumferential profile methods used in planar scintigraphy but requires a polar-to-cartesian transformation from three to two dimensions. As was the case in the planar situation, centering and reorientation are explicit. The degree of data reduction is evaluated by reconstructing idealized three-dimensional data from the two-dimensional sampling vectors. The method differs from previously described approaches by the absence in the resulting vector of a coordinate reflecting cartesian coordinate in the original data (slice number)

Two-dimensional and three-dimensional analyses of sigma precipitates and porosity in a superaustenitic stainless steel

DEFF Research Database (Denmark)

Fonda, Richard Warren; Lauridsen Mejdal, Erik; Ludwig, W.

2007-01-01

X-ray micro-tomography revealed not only the true three-dimensional (3-D) distribution, interconnectivity, and morphology of coarse sigma precipitates in an AL-6XN superaustenitic stainless steel, but also the presence of an internal void network associated with these precipitates. The voids were...

Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise.

Science.gov (United States)

Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

2012-05-01

A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ~0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule. © 2012 International Union of Crystallography

A two-dimensional layered Cd(II) coordination polymer with a three-dimensional supramolecular architecture incorporating mixed multidentate N- and O-donor ligands.

Science.gov (United States)

Huang, Qiu-Ying; Su, Ming-Yang; Meng, Xiang-Ru

2015-06-01

The combination of N-heterocyclic and multicarboxylate ligands is a good choice for the construction of metal-organic frameworks. In the title coordination polymer, poly[bis{μ2-1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole-κ(2)N(3):N(4)}(μ4-butanedioato-κ(4)O(1):O(1'):O(4):O(4'))(μ2-butanedioato-κ(2)O(1):O(4))dicadmium], [Cd(C4H4O4)(C9H8N6)]n, each Cd(II) ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from three carboxylate groups of three succinate (butanedioate) ligands and two N atoms from two 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) ligands. Cd(II) ions are connected by two kinds of crystallographically independent succinate ligands to generate a two-dimensional layered structure with bimt ligands located on each side of the layer. Adjacent layers are further connected by hydrogen bonding, leading to a three-dimensional supramolecular architecture in the solid state. Thermogravimetric analysis of the title polymer shows that it is stable up to 529 K and then loses weight from 529 to 918 K, corresponding to the decomposition of the bimt ligands and succinate groups. The polymer exhibits a strong fluorescence emission in the solid state at room temperature.

Quantitative study of two- and three-dimensional strong localization of matter waves by atomic scatterers

International Nuclear Information System (INIS)

Antezza, Mauro; Castin, Yvan; Hutchinson, David A. W.

2010-01-01

We study the strong localization of atomic matter waves in a disordered potential created by atoms pinned at the nodes of a lattice, for both three-dimensional (3D) and two-dimensional (2D) systems. The localization length of the matter wave, the density of localized states, and the occurrence of energy mobility edges (for the 3D system), are numerically investigated as a function of the effective scattering length between the atomic matter wave and the pinned atoms. Both positive and negative matter wave energies are explored. Interesting features of the density of states are discovered at negative energies, where maxima in the density of bound states for the system can be interpreted in terms of bound states of a matter wave atom with a few pinned atomic scatterers. In 3D we found evidence of up to three mobility edges, one at positive energies, and two at negative energies, the latter corresponding to transitions between extended and localized bound states. In 2D, no mobility edge is found, and a rapid exponential-like increase of the localization length is observed at high energy.

Three-dimensional oscillator and Coulomb systems reduced from Kaehler spaces

International Nuclear Information System (INIS)

Nersessian, Armen; Yeranyan, Armen

2004-01-01

We define the oscillator and Coulomb systems on four-dimensional spaces with U(2)-invariant Kaehler metric and perform their Hamiltonian reduction to the three-dimensional oscillator and Coulomb systems specified by the presence of Dirac monopoles. We find the Kaehler spaces with conic singularity, where the oscillator and Coulomb systems on three-dimensional sphere and two-sheet hyperboloid originate. Then we construct the superintegrable oscillator system on three-dimensional sphere and hyperboloid, coupled to a monopole, and find their four-dimensional origins. In the latter case the metric of configuration space is a non-Kaehler one. Finally, we extend these results to the family of Kaehler spaces with conic singularities

Equilibrium vortex motion in two- and three-dimensional superconductors studied with a dc SQUID

International Nuclear Information System (INIS)

Shaw, T.J.; Lawrence Berkeley National Lab., CA

1997-10-01

The equilibrium motion of vortices in two- and three-dimensional superconductors has been studied with a dc Superconducting QUantum Interference Device (SQUID). This technique has the advantage of probing the system in a non-invasive manner as well as providing dynamic information over many decades in frequency. Through measurements of the spectral density of magnetic flux noise, S Φ (ω), as a function of temperature and applied magnetic field, the effects of proton and heavy ion irradiation on flux noise in crystals of YBa 2 Cu 3 O 7-δ have been measured and compared with the effects on the critical current, J c . Both proton and heavy ion irradiation proved effective at reducing S Φ (ω), with proton irradiation having a larger effect. Measurement of S Φ (ω) due to the equilibrium Kosterlitz-Thouless-Berezinskii transition in two-dimensional Josephson Junction Arrays (JJAs) was studied as a function of temperature for three different arrays and using three different sensors. S Φ is shown to obey dynamic scaling over as many as five decades in frequency, and estimates are made for the dynamic critical exponent z. An analytic theory for the high- and low-frequency behavior of S Φ (ω) is presented and compared to the measured data, with the result that the low-frequency behavior is well described by the theory but the high-frequency behavior is not. Other theories and numerical simulations are described and compared with the data, but none are completely satisfactory. Lastly, suggestions for necessary further theoretical work and possible future experimental work are suggested

Two-dimensional power Doppler-three-dimensional ultrasound imaging of a cesarean section dehiscence with utero-peritoneal fistula: a case report

Directory of Open Access Journals (Sweden)

Royo Pedro

2009-01-01

Full Text Available Abstract Introduction An imaging diagnosis after an iterative cesarean delivery is reviewed demonstrating a fine ultrasound-pathologic correlation. Case presentation A 33-year-old woman (G3, P3 presented referring intense dysmenorrhea and intermenstrual spotting since her third cesarean delivery, 1 year before. A cesarean section dehiscence with utero-peritoneal fistula was diagnosed by transvaginal ultrasound. Conclusion We can conclude that transvaginal two-dimensional power Doppler and three-dimensional ultrasound are highly accurate in detecting cesarean section dehiscence and uterine fistula.

SNAP - a three dimensional neutron diffusion code

International Nuclear Information System (INIS)

McCallien, C.W.J.

1993-02-01

This report describes a one- two- three-dimensional multi-group diffusion code, SNAP, which is primarily intended for neutron diffusion calculations but can also carry out gamma calculations if the diffusion approximation is accurate enough. It is suitable for fast and thermal reactor core calculations and for shield calculations. SNAP can solve the multi-group neutron diffusion equations using finite difference methods. The one-dimensional slab, cylindrical and spherical geometries and the two-dimensional case are all treated as simple special cases of three-dimensional geometries. Numerous reflective and periodic symmetry options are available and may be used to reduce the number of mesh points necessary to represent the system. Extrapolation lengths can be specified at internal and external boundaries. (Author)

Method and system for manipulating a digital representation of a three-dimensional object

DEFF Research Database (Denmark)

2010-01-01

A method of manipulating a three-dimensional virtual building block model by means of two-dimensional cursor movements, the virtual building block model including a plurality of virtual building blocks each including a number of connection elements for connecting the virtual building block...... with another virtual building block according to a set of connection rules, the method comprising positioning by means of cursor movements in a computer display area representing a two-dimensional projection of said model, a two-dimensional projection of a first virtual building block to be connected...... to the structure, resulting in a two-dimensional position; determining, from the two-dimensional position, a number of three-dimensional candidate positions of the first virtual building block in the three-dimensional coordinate system; selecting one of said candidate positions based on the connection rules...

Flukacad/Pipsicad: three-dimensional interfaces between Fluka and Autocad

International Nuclear Information System (INIS)

Helmut Vincke

2001-01-01

FLUKA is a widely used 3-D particle transport program. Up to now there was no possibility to display the simulation geometry or the calculated tracks in three dimensions. Even with FLUKA there exists only an option to picture two-dimensional views through the geometry used. This paper covers the description of two interface programs between the particle transport code FLUKA and the CAD program AutoCAD. These programs provide a three-dimensional facility not only for illustrating the simulated FLUKA geometry (FLUKACAD), but also for picturing simulated particle tracks (PIPSICAD) in a three-dimensional set-up. Additionally, the programming strategy for connecting FLUKA with AutoCAD is shown. A number of useful features of the programs themselves, but also of AutoCAD in the context of FLUKACAD and PIPSICAD, are explained. (authors)

Two iridates, two models, and two approaches: A comparative study on magnetism in three-dimensional honeycomb materials

Science.gov (United States)

Lee, Eric Kin-Ho; Rau, Jeffrey G.; Kim, Yong Baek

2016-05-01

Two recent theoretical works studied the role of Kitaev interactions in the newly observed incommensurate magnetic order in the hyper-honeycomb (β -Li2IrO3 ) and stripy-honeycomb (γ -Li2IrO3 ) iridates. Each of these works analyzed a different model (J K Γ versus coupled zigzag chain model) using a contrasting method (classical versus soft-spin analysis). The lack of commonality between these works precludes meaningful comparisons and a proper understanding of these unusual orderings. In this study, we complete the unfinished picture initiated by these two works by solving both models with both approaches for both three-dimensional (3D) honeycomb iridates. Through comparisons between all combinations of models, techniques, and materials, we find that the bond-isotropic J K Γ model consistently predicts the experimental phase of β -Li2IrO3 regardless of the method used, while the experimental phase of γ -Li2IrO3 can be generated by the soft-spin approach with eigenmode mixing irrespective of the model used. To gain further insights, we solve a one-dimensional (1D) quantum spin-chain model related to both 3D models using the density matrix renormalization group method to form a benchmark. We discover that in the 1D model, incommensurate correlations in the classical and soft-spin analysis survive in the quantum limit only in the presence of the symmetric-off-diagonal exchange Γ found in the J K Γ model. The relevance of these results to the real materials is also discussed.

Hydrothermal preparation of nickel(II)/uranium(IV) fluorides with one-, two-, and three-dimensional topologies.

Science.gov (United States)

Bean, Amanda C; Sullens, Tyler A; Runde, Wolfgang; Albrecht-Schmitt, Thomas E

2003-04-21

A modified compositional diagram for the reactions of Ni(C(2)H(3)O(2))(2).4H(2)O with UO(2)(C(2)H(3)O(2))(2).2H(2)O and HF in aqueous media under mild hydrothermal conditions (200 degrees C) has been completed to yield three Ni(II)/U(IV) fluorides, Ni(H(2)O)(4)UF(6).1.5H(2)O (1), Ni(2)(H(2)O)(6)U(3)F(16).3H(2)O (2), and Ni(H(2)O)(2)UF(6)(H(2)O) (3). The structure of 1 consists of one-dimensional columns constructed from two parallel chains of edge-sharing dodecahedral [UF(8)] units. The sides of the columns are terminated by octahedral Ni(II) units that occur as cis-[Ni(H(2)O)(4)F(2)] polyhedra. In contrast, the crystal structure of 2 reveals a two-dimensional Ni(II)/U(IV) architecture built from edge-sharing tricapped trigonal prismatic [UF(9)] units. The top and bottom of the sheets are capped by fac-[Ni(H(2)O)(3)F(3)] octahedra. The structure of 3 is formed from [UF(8)(H(2)O)] tricapped trigonal prisms that edge share with one another to form one-dimensional chains. These chains are then joined together into a three-dimensional network by corner sharing with trans-[Ni(H(2)O)(2)F(4)] octahedra. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 14.3383(8) A, b = 15.6867(8) A, c = 8.0282(4) A, Z = 8; 2, hexagonal, space group P6(3)/mmc, a = 7.9863(5) A, c = 16.566(1) A, Z = 2; 3, monoclinic, space group C2/c, a = 12.059(1) A, b = 6.8895(6) A, c = 7.9351(7) A, beta = 92.833(2) degrees, Z = 4.

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....

Three-dimensional liver motion tracking using real-time two-dimensional MRI.

Science.gov (United States)

Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

2014-04-01

Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Axial, sagittal, and coronal 2D MRI series

Three-dimensional liver motion tracking using real-time two-dimensional MRI

Energy Technology Data Exchange (ETDEWEB)

Brix, Lau, E-mail: lau.brix@stab.rm.dk [Department of Procurement and Clinical Engineering, Region Midt, Olof Palmes Allé 15, 8200 Aarhus N, Denmark and MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Ringgaard, Steffen [MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, Aabogade 34, 8200 Aarhus N, Denmark and Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Poulsen, Per Rugaard [Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark and Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark)

2014-04-15

Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

Three-dimensional liver motion tracking using real-time two-dimensional MRI

International Nuclear Information System (INIS)

Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

2014-01-01

Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal