Geometric comparison of the mitral and tricuspid valve annulus:Insights from three dimensional transesophageal echocardiography

AIM To apply real time three-dimensional transesophageal echocardiography(RT3D TEE) for quantitative and qualitative assessment of the mitral valve annulus(MVA) and tricuspid valve annulus(TVA) in the same patient.METHODS Our retrospective cohort study examined the MVA and TVA in 49 patients by RT3 D TEE. MVA and TVA shape were examined by TEE. The MVA and TVA volume data set images were acquired in the mid esophageal 4-chamber view. The MVA and TVA were acquired separately, with optimization of each for the highest frame rate and image quality. The 3D shape of the annuli was reconstructed using the Philips~? Q lab, MVQ ver. 6.0 MVA model software. The end-systolic frame was used. The parameters measured and compared were annular area, circumference, high-low distances(height), anterolateralposterolateral(ALPM), and anteroposterior(AP) axes. RESULTS A total of 49 patients(mean age 61 ± 14 years, 45% males) were studied. The ALPM and the AP axes of the MVA and TVA are not significantly different. The ALPM axis of the MVA was 37.9 ± 6.4 mm and 38.0 ± 5.6 mm for the TVA(P = 0.70). The AP axis of the MVA was 34.8 ± 5.7 mm and 34.9 ± 6.2 mm for the TVA(P = 0.90). The MVA and the TVA had similar circumference and area. The circumference of the MVA was 127.9 ± 16.8 mm and 125.92 ± 16.12 mm for the TVA(P = 0.23). The area of the MVA was 1103.7 ± 307.8 mm^2 and 1131.7 ± 302.0 mm^2 for the TVA(P = 0.41). The MVA and TVA are similar oval structures, but with significantly different heights. The ALPM/AP ratio for the MVA was 1.08 ± 0.33 and 1.09 ± 0.28 for the TVA(P < 0.001). The height for the MVA and TVA was 9.23 ± 2.11 mm and 4.37 ± 1.48 mm, respectively(P < 0.0001). CONCLUSION RT3 D TEE plays an unprecedented role in the management of valvular heart disease. The specific and exclusive shape of the MVA and TVA was revealed in our study of patients studied. Moreover, the intricate codependence of the MVA and the TVA depends on their distinctive shapes. This realization seen from our study will allow us to better understand the role valvular disease plays in disease states such as hypertrophic cardiomyopathy and pulmonary hypertension.

Evaluation of Atrial Septal Defect Using Real-time Three-dimensional Echocardiography:Comparison with Surgical Findings

The present study evaluated the application of three dimensional echocardigraphy （3DE） in the diagnosis of atrial septal defect （ASD） and the measurement of its size by 3DE and compared the size with surgical findings. Two-dimensional and real-time three dimensional echocardiography （RT3DE） was performed in 26 patients with atrial septal defect, and the echocardiographic data were compared with the surgical findings. Significant correlation was found between defect diameter by RT3DE and that measured during surgery （r=0.77, P〈0.001）. The defect area changed significantly during cardiac cycle. Percentage change in defect size during cardiac cycle ranged from 6%-70%. Our study showed that the size and morphology of atrial septal defect obtained with RT3DE correlate well with surgical findings. Therefore, RT3DE is a feasible and accurate non-invasive imaging tool for assessment of atrial septal size and dynamic changes.

Catheter ablation of atrial fibrillation facilitated by preprocedural three-dimensional transesophageal echocardiography: Long-term outcome

AIM To evaluate the long-term outcome of catheter ablation of atrial fibrillation(AF) facilitated by preprocedural threedimensional(3-D) transesophageal echocardiography.METHODS In 50 patients, 3D transesophageal echocardiography(3D TEE) was performed immediately prior to an ablation procedure(paroxysmal AF: 30 patients, persistent AF: 20 patients). The images were available throughout the ablation procedure. Two different ablation strategies were used. In most of the patients with paroxysmal AF, the cryoablation technique was used(Arctic Front Balloon, Cryo Cath Technologies/Medtronic; group A2). In the other patients, a circumferential pulmonary vein ablation was performed using the CARTO system [Biosense Webster; group A1(paroxysmal AF), group B(persistent AF)]. Success rates and complication rates were analysed at 4-year follow-up.RESULTS A 3D TEE could be performed successfully in all patients prior to the ablation procedure and all four pulmonaryvein ostia could be evaluated in 84% of patients. The image quality was excellent in the majority of patients and several variations of the pulmonary vein anatomy could be visualized precisely(e.g., common pulmonary vein ostia, accessory pulmonary veins, varying diameter of the left atrial appendage and its distance to the left superior pulmonary vein). All ablation procedures could be performed as planned and almost all pulmonary veins could be isolated successfully. At 48-mo followup, 68.0% of all patients were free from an arrhythmia recurrence(group A1: 72.7%, group A2: 73.7%, group B: 60.0%). There were no major complications.CONCLUSION3 D TEE provides an excellent overview over the left atrial anatomy prior to AF ablation procedures and these procedures are associated with a favourable long-term outcome.

Incremental value of three-dimensional and contrast echocardiography in the evaluation of endocardial fibroelastosis and multiple cardiovascular thrombi: A case report

BACKGROUND Endocardial fibroelastosis(EFE)is a rare heart disease characterized by thickening of the endocardium caused by massive proliferation of collagenous and elastic tissue,usually leading to impaired cardiac function.Multimodality cardiovascular imaging for the evaluation of EFE with thrombi is even rarer.CASE SUMMARY We report a rare case of EFE associated with multiple cardiovascular thrombi.Three-dimensional(3D)and contrast echocardiography(CE)were used to assess ventricular thrombi.Anticoagulant therapy was administered to eliminate the thrombi.The peripheral contrast-enhanced thrombi with the highest risk were dissolved with anticoagulant therapy at the time of reexamination,which was consistent with the presumption of fresh loose thrombi.CONCLUSION This new echocardiography technique has a great advantage in the diagnosis and treatment of EFE.On the basis of conventional echocardiography,3D echocardiography is used to display the position,shape,and narrow base of the thrombus.CE does not only help to confirm the diagnosis of thrombus,but also determines its risk.

Effects of sevoflurane on left ventricular function by speckletracking echocardiography in coronary bypass patients: A randomized trial

The present study aimed to dynamically observe the segmental and global myocardial movements of the left ventricle during coronary artery bypass grafting by transesophageal speckle-tracking echocardiography,and to assess the effect of sevoflurane on cardiac function.Sixty-four patients scheduled for the off-pump coronary artery bypass grafting were randomly divided into a sevoflurane-based anesthesia(AS)group and a propofolbased total intravenous anesthesia(AA)group.The AS group demonstrated a higher absolute value of left ventricular global longitudinal strain than that of the AA group at both T1(after harvesting all grafts and before coronary anastomosis)and T_(2)(30 min after completing all coronary anastomoses)(P<0.05).Moreover,strain improvement in the segment with the highest preoperative strain was significantly reduced in the AS group,compared with the AA group at both T1 and T_(2)(P<0.01).The flow of the left internal mammary artery-left anterior descending artery graft was superior,and the postoperative concentration of troponin T decreased rapidly in the AS group,compared with the AA group(P<0.05).Compared with total intravenous anesthesia,sevoflurane resulted in a significantly higher global longitudinal strain,stroke volume,and cardiac output.Sevoflurane also led to an amelioration in the condition of the arterial graft.Furthermore,sevoflurane significantly reduced strain improvement in the segmental myocardium with a high preoperative strain value.The findings need to be replicated in larger studies.

Evaluation of Right Ventricular Volume and Systolic Function by Real-time Three-dimensional Echocardiography

The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV “Full volume” images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpson's rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r=0.73; r=0.69; r=0.63; r=0.66, P<0.25—0.0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P<0.001). There was also difference between RV volume in 4-plane and that in 8-plane (P<0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P>0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r=0.986, P<0.001; r=0.93, P<0.001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r=0.83; r=0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RV's complex shape, apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function.

Assessment of Left Atrial Function by Full Volume Real-time Three-dimensional Echocardiography and Left Atrial Tracking in Essential Hypertension Patients with Different Patterns of Left Ventricular Geometric Models

Objective To evaluate left atrial function in essential hypertension patients with different patterns of left ventricular geometric models by real-time three-dimensional echocardiography （RT-3DE） and left atrial tracking （EAT）.

Role of real-time three-dimensional transesophageal echocardiography in mitral valve repair

Background and objective Pre-operative assessment of mitral valve (MV) anatomy is essential to surgical design in patients undergoing MV repair.Although 2-dimensional (2D) echocardiography provides precise information regarding MV anatomy,RT-3D TEE could increase the understanding of MV apparatus and individual scallop identification.We aimed to investigate the value of RT- 3DTEE in MV repair.Methods RT-3DTEE was performed in six patients with mitral valve prolapse (MVP) by using Philips 1E33 with X7-2t probe.Preoperative RT-3DTEE studies were compared with surgical findings in patients undergoing surgical mitral valve repair,and quantitative evaluation was performed by QLab 6.0 software before and after surgical mitral valve repair.Results RT- 3DTEE could display dynamic morphology of MV,the location of prolapse,and spatial relation to the surrounding tissue.It could provide surgical views of the valves and the valvular apparatus.These results were consistent with surgical findings.The quantitative evaluation before and after surgical MV repair indicated that anterolateral to posteromedial diameter of annulus,anterior to posterior diameter of annulus,perimeter of annulus,and area of annulus in projection plane were significantly smaller after operation compared with those before operation (P【0.05).The length of posterior leaflet,the area of anterior and posterior leaflet,the maximal prolapse height,the volume of leaflet prolapse and the length of coaptation in projection plane were significantly reduced after operation (P【0. 05).Conclusion RT-3DTEE is a unique new modality for rapid and accurate evaluation ofmitral valve prolapse and mitral valve repair.

Left Ventricular Systolic Strain of the Cardiac Allograft Evaluated with Three-dimensional Speckle Tracking Echocardiography

Three-dimensional speckle tracking echocardiography was employed to evaluate the changes of left ventricular systolic strain in 23 heart transplant recipients at 1 st, 3rd, 6th and 12th month after heart transplantation, and 23 healthy subjects served as controls. The three-dimensional full-volume echocardiographic images of left ventricle were recorded and then were analyzed using EchoPAC software. The strain curves and peak systolic strain values for each segment and overall left ventricular wall were obtained. Left ventricular global peak longitudinal strain （GPSL）, global peak radial strain （GPSR）, global peak circumferential strain （GPSC） and global peak area strain （GPSA） were measured and then statistically analyzed. There were no significant differences in left ventricular ejection fraction （LVEF） and cardiac output （CO） between heart transplant recipients and controls. The GPSL in heart transplant recipients at 1st month after surgery was significantly lower than that in controls, but close to the normal value at 3rd month after surgery and later. The GPSC, GPSA and GPSR were significantly lower in heart transplant recipients at 1 st, 3rd, 6th and 12th month after surgery than those in controls. It is suggested that three-dimensional speckle tracking echocardiography can be used for monitoring changes of left ventricular systolic strains and evaluating left ventricular systolic function in cardiac allograft.

REAL-TIME THREE-DIMENSIONAL ECHOCARDIOGRAPHY FOR QUANTIFYING LEFT VENTRICULAR MASS

To test the accuracy of real-time three-dimensional echocardiography (RT3DE) imaging system for evaluating left ventricular mass (LVM) in phantom and excised canine heart. Methods Ten left ventricular (LV) wall phantoms made of two rubber-bursas, ten excised canine hearts underwent RT3DE and two-dimensional echocardiography (2DE). In RT3DE "full volume" imaging, the myocardial volume was mea-sured using 2,4,8, and 16-plane method with the analysis software of RT3DE. Mass was then calculated by multiplying the resulting myocardial volume by specific density of myocardial tissue. In 2DE the masses were measured by area-length meth-od. The true LV wall phantom mass was measured by water displacement and the canine LVM was weighed by anatomy, which served as a reference standard. We compared RT3DE or 2DE with true mass. Results In LV wall phantoms, RT3DE correlated with true masses strongly (r = 0.813-0.994) and weakly correlated between 2DE and true masses (r = 0.628). In excised canine hearts, there is an excellent correlation between RT3DE and true masses (r = 0.764-0.991), while 2DE value showed a lesser correlation (r = 0.514). There are no difference between RT-3DE and true masses (P > 0.05) but different between 2DE and true masses (P < 0.05). In different planes, there was no difference between 8-plane and 16-plane (P > 0.05) but different between 8-plane and 2, 4-plane (P < 0.05). Conclusion RT3DE can accurately quantify LVM and provide a new tool to evaluate LV function. For LVM by RT3DE, 8-plane measurement method is the best choice for accuracy and convenience.

Clinical Value of Stereoscopic Three-dimensional Echocardiography in Assessment of Atrial Septal Defects: Feasibility and Efficiency

Stereoscopic three-dimensional echocardiography（S-3DE） is a novel displaying technol-ogy based on real-time 3-dimensional echocardiography （RT-3DE）. Our study was to evaluate the feasibility and efficiency of S-3DE in the diagnosis of atrial septal defect （ASD） and its use in the guidance for transcatheter ASD occlusion. Twelve patients with secundum ASD underwent RT-3DE examination and 9 of the 12 were subjected to transcatheter closure of ASD. Stereoscopic vision was generated with a high-performance volume renderer with red-green stereoscopic glasses. S-3DE was compared with standard RT-3D display for the assessment of the shape, size, and the surrounding tis-sues of ASD and for the guidance of ASD occlusion. The appearance rate of coronary sinus and the mean formation time of the IVC, SVC were compared. Our results showed that S-3DE could measure the diameter of ASD accurately and there was no significant difference in the measurements between S-3DE and standard 3D display （2.89±0.73 cm vs 2.85±0.72 cm, P〉0.05; r=0.96, P〈0.05）. The appearance of coronary sinus for S-3DE was higher as compared with the standard 3D display （93.3% vs 100%）. The mean time of the IVC, SVC for S-3DE monitor was slightly shorter than that of the standard 3D display （11.0±3.8 s vs 10.3±3.6 s, P〉0.05）. The mean completion time of interven-tional procedure was shortened with S-3DE display as compared with standard 3D display （17.3±3.1 min vs 23.0±3.9 min, P〈0.05）. Stereoscopic three-dimensional echocardiography could improve the visualization of three-dimensional echocardiography, facilitate the identification of the adjacent structures, decrease the time required for interventional manipulation. It may be a feasible, safe, and efficient tool for guiding transcatheter septal occlusion or the surgical interventions.

Surgical Resection of Mitral Valve Papillary Fibroelastoma: A Robot-Assisted, Minimally Invasive Approach with Three-Dimensional Transesophageal Echocardiography Imaging

Papillary fibroelastomas (PFEs) are benign tumors of the endocardium that most frequently affect cardiac valves and typically present with embolic symptoms such as stroke or transient ischemic attack (TIA). Surgical excision is usually recommended for left-sided tumors and is associated with excellent long-term outcomes. The use of a robot-assisted, minimally invasive surgical approach for management of mitral valve disease is growing, and has been associated with shorter hospital stays and improved early quality of life. Three-dimensional (3D) transesophageal echocardiography (TEE) offers several advantages in the assessment of mitral valve disease and cardiac tumors, including the ability to precisely locate the site of attachment of the mass and the spatial relationships to surrounding structures. These factors are particularly important when planning a surgical approach. We report two cases of mitral valve PFEs which were successfully removed using a robot-assisted, minimally invasive surgical approach with 3D TEE imaging. This approach to treatment of PFEs is an attractive alternative to the traditional approach involving median sternotomy.

Real-time three-dimensional echocardiography predicts cardiotoxicity induced by postoperative chemotherapy in breast cancer patients

BACKGROUND The anthracycline chemotherapeutic drugs are cardiotoxic.Studies have found some indicators related to cardiotoxicity.However,there is currently no accurate indicator that can predict cardiac toxicity early.AIM To explore the diagnostic value of real-time three-dimensional echocardiography(RT3DE)in predicting cardiac toxicity in breast cancer patients undergoing chemotherapy.METHODS Female breast cancer patients who underwent radical mastectomy and postoperative chemotherapy at the Affiliated Hanzhou First People’s Hospital,Zhejiang University School of Medicine were recruited.All patients were routinely administered with chemotherapy for four cycles(T1-T4)after surgery.Two-dimensional(2D)echocardiography,RT3DE,and serological examinations were performed after each cycle of chemotherapy.Patients were divided into a toxic group and a non-toxic group based on whether patients hadΔleft ventricular ejection fraction>10%after one year of chemotherapy.Repeated measurement analysis of variance was used to compare the changes in 2D echocardiographic indicators,serological indicators,and RT3DE indicators before independent predictive indicators for cardiac toxicity in postoperative chemotherapy patients.Receiver operating characteristics(ROC)curve analysis was performed to analyze the diagnostic value of potential indicators in the diagnosis of cardiotoxicity.RESULTS A total of 107 female breast cancer patients were included in the study.T4 maximum peak velocity in early diastole(E peak)/mitral annulus lateral tissue Doppler(e'peak)(E/e'),serological indicators[T4 cardiac troponin I(cTnI)and T4 pro-brain natriuretic peptide(Pro-BNP)],T3 minimum left atrial volume(LAV),T4 LAVmin,T3 LAV before the start of the P wave(LAVprep),and T4 LAVprep in the toxicity group were significantly higher than those in the nontoxic group.Multivariate logistic regression found that T4 cTnI,T4 Pro-BNP,T3 LAVmin,T4 LAVmin,T3 LAVprep,and T4 LAVprep had potential predictive value for cardiac toxicity(P<0.05).ROC results showed that T4 LAVmin had the highest accuracy for diagnosing cardiac toxicity[area under the curve(AUC)=0.947;sensitivity=78.57%;specificity=94.62%],followed by T4 LAVprep(AUC=0.899;sensitivity=100%;specificity=66.67%).The accuracies of LAVprep and LAVprep in predicting cardiac toxicity were higher than those of T3 LAVmin and T3 LAVprep.CONCLUSION RT3DE of left atrial volume can be used to predict the cardiotoxicity caused by chemotherapy,and it is expected to guide the clinical adjustment of dose and schedule in time.

QUANTITATIVE ASSESSMENT OF MYOCARDIAL PERFUSION DEFECTS WITH REAL-TIME THREE-DIMENSIONAL MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY

Objective To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3DE). Methods RT3DE was performed in 21 open-chest mongrel dogs undergoing acute ligation of the left anterior descending artery (LAD, n=14) or distal branch of the left circumflex artery (LCX, n=7). A perfluorocarbon microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with Philips Sonos-7500 ultrasound system. Evans blue dye was injected into the occluded coronary artery for subsequent anatomic identification of underperfused myocardium. In vitro anatomic measurement of myocardial mass after removal of the animal’s heart was regarded as the control. Blinded off-line calculation of left ventricular mass and perfusion defect mass from RT3DE images were performed using an interactive aided-manual tracing technique.Results Total left ventricular (LV) myocardial mass ranged from 38.9 to 78.5 (mean±SD: 60.0±10.1) g. The mass of perfusion defect ranged from 0 to 21.4 (mean±SD: 12.0±5.0) g or 0 to 27% of total LV mass (mean±SD: 19%±6%). The RT3DE estimation of total LV mass (mean±SD: 59.8±9.9 g) strongly correlated with the anatomic measurement (r=0.98; y=2.01+0.96x). The CE-RT3DE calculation of the mass of underperfused myocardium (mean±SD: 12.3±5.3 g) also strongly correlated with the anatomic measurement (r=0.96; y=-0.10+1.04x) and when expressed as percentage of total LV mass (r=0.95; y=-0.20+1.04x). Conclusions RT3DE with myocardial contrast opacification could accurately estimate underperfused myocardial mass in dogs of acute coronary occlusion and would play an important role in quantitative assessment of myocardial perfusion defects in patients with coronary artery disease.

Evaluation of Left Ventricular Function by Three-Dimensional Speckle-Tracking Echocardiography in Patients with Chronic Kidney Failure

Objective:To establish a quantitative evaluation of the left ventricle's systolic function in patients with chronic kidney failure(CKF)by three-dimensional speckle-tracking echocardiography.Methods:Two-dimensional and three-dimensional transthoracic echocardiography was performed on 30 patients with CKF.The ejection fraction,mass and global peak longitudinal strain,global circumferential strain,global area strain,and global radial strain of the left ventricle were calculated.Results:The ejection fraction,mass and global peak longitudinal strain(GLS),global circumferential strain(GCS),global area strain(GAS),and global radial strain(GRS)in the CKF group were significantly lower than those in the control group.Simultaneously,the GLS,GCS,GAS and GRS were well correlated with the ejection fraction.For patients with normal ejection fraction in the CKF group,the GLS,GCS,GAS and GRS were lower than those in the control group,while the left ventricular mass was significantly higher in CKF patients than in the control group.For patients with hypertension in the CKF group,ejection fraction,GLS,GCS,GAS and GRS calculated using three-dimensional echocardiography were significantly lower than those in patients with normal blood pressure;however,the myocardial mass was higher.Conclusions:The parameters(GLS,GCS,GAS and GRS)calculated using three-dimensional speckle-tracking software were lower in the CKF group.Simultaneously,the left ventricular mass was higher in CFK patients than in the control group,thus showing that the myocardial contraction function was impaired and that myocardial remodeling had occurred.

Deep learning models semi-automatic training system for quality control of transthoracic echocardiography

Objective To explore the value of deep learning(DL)models semi-automatic training system for automatic optimization of clinical image quality control of transthoracic echocardiography(TTE).Methods Totally 1250 TTE videos from 402 patients were retrospectively collected,including 490 apical four chamber(A4C),310 parasternal long axis view of left ventricle(PLAX)and 450 parasternal short axis view of great vessel(PSAX GV).The videos were divided into development set(245 A4C,155 PLAX,225 PSAX GV),semi-automated training set(98 A4C,62 PLAX,90 PSAX GV)and test set(147 A4C,93 PLAX,135 PSAX GV)at the ratio of 5∶2∶3.Based on development set and semi-automatic training set,DL model of quality control was semi-automatically iteratively optimized,and a semi-automatic training system was constructed,then the efficacy of DL models for recognizing TTE views and assessing imaging quality of TTE were verified in test set.Results After optimization,the overall accuracy,precision,recall,and F1 score of DL models for recognizing TTE views in test set improved from 97.33%,97.26%,97.26%and 97.26%to 99.73%,99.65%,99.77%and 99.71%,respectively,while the overall accuracy for assessing A4C,PLAX and PSAX GV TTE as standard views in test set improved from 89.12%,83.87%and 90.37%to 93.20%,90.32%and 93.33%,respectively.Conclusion The developed DL models semi-automatic training system could improve the efficiency of clinical imaging quality control of TTE and increase iteration speed.

BILL Strategy:Points to Consider During the Performance and Interpretation of Critical Care Echocardiography

The growing utilization of critical care echocardiography(CCE) by clinicians necessitates a meticulous review of clinical conditions in critically ill patients, both before and during the examination. The reviewing process of clinical conditions minimizes the risk of overlooking or misinterpreting crucial findings. This article proposes a comprehensive strategy, namely BILL strategy, to integrate into the CCE protocol, where "B" represents baseline respiratory and hemodynamic support, "I" signifies information gleaned from invasive monitoring, including central venous pressure and thermodilution-derived cardiac output, the first "L" denotes laboratory results such as central venous oxygen saturation, troponin, and brain natriuretic peptide, and the second "L" refers to lung ultrasound data. Combining the BILL strategy with CCE can enhance comprehensive understanding of critical conditions, potentially leading to improved diagnostic accuracy and patient outcomes.

Clinical Application of Three－dimensional Transesophageal Echocardiography in the Diagnosis of Atrial Septal Defect

This paper reports the use of three-dimensional (3-D) transesophageal echocardiography(TEE) in the diagnosis of atrial septal defect. The results displayed that the interatrial septum had integrity in normal persons. The size,shape and position of atrial septal defects could be showed clearly and the type of the defects could be identified. The reconstructed imaging of interatrial septum on 3-D TEE was clear and stereoscopic. The technique is helpful in defining spatial location and extent of atrial septal defects.

A modified OMP method for multi-orbit three dimensional ISAR imaging of the space target

The conventional two dimensional(2D)inverse synthetic aperture radar(ISAR)imaging fails to provide the targets'three dimensional(3D)information.In this paper,a 3D ISAR imaging method for the space target is proposed based on mutliorbit observation data and an improved orthogonal matching pursuit(OMP)algorithm.Firstly,the 3D scattered field data is converted into a set of 2D matrix by stacking slices of the 3D data along the elevation direction dimension.Then,an improved OMP algorithm is applied to recover the space target's amplitude information via the 2D matrix data.Finally,scattering centers can be reconstructed with specific three dimensional locations.Numerical simulations are provided to demonstrate the effectiveness and superiority of the proposed 3D imaging method.

Z-Score in Fetal Echocardiography–Is there Still Room for New Studies?

Congenital heart disease(CHD)is the most common type of birth defect,representing a significant cause of peri-natal morbidity and mortality.Early diagnosis of such anomalies is crucial for improving outcomes.Current pro-tocols recommend a qualitative assessment of cardiac structures using two-dimensional ultrasound(2DUS)and color Doppler imaging.In cases of suspected abnormalities,quantitative assessments through cardiac structure measurements and reference curves can aid in accurate diagnosis.Similar to centiles widely employed in obste-trics,Z-scores provide more precise quantification of various cardiac structures,particularly at the extremes of the curve.While the development of reference curves and Z-scores has progressed over the past two decades,a lack of standardization in measurements and statistical methodology for their determination is evident.Establishing reference curves requires adherence to specific recommendations to improve their accuracy.The purpose of this study is to provide a narrative review of the major studies that have generated reference values for cardiac struc-tures using 2DUS and Z-scores,to evaluate their methodology,and to provide a summary of the results.