Assessment of flail mitral leaflets by dynamic three-dimensional echocardiographic imaging

Three-Dimensional Echocardiography Assessment of Right Ventricular Volumes and Function: Technological Perspective and Clinical Application

Right ventricular (RV) function has important prognostic value in a variety of cardiovascular diseases. Due to complex anatomy and mode of contractility, conventional two-dimensional echocardiography does not provide sufficient and accurate RV function assessment. Currently, three-dimensional echocardiography (3DE) allows for an excellent and reproducible assessment of RV function owing to overcoming these limitations of traditional echocardiography. This review focused on 3DE and discussed the following points: (i) acquisition of RV dataset for 3DE images, (ii) reliability, feasibility, and reproducibility of RV volumes and function measured by 3DE with different modalities, (iii) the clinical application of 3DE for RV function quantification.

Echocardiography and Correction of Mitral Regurgitation: An Unbreakable Link

Background: Degenerative mitral valve (MV) disease causing mitral regurgitation (MR) is the most common organic valve pathology and is classified based on leaflet motion. MV repair is indicated as the preferred technique (Class I indication) when the results are expected to be durable. Therefore, a detailed and systematic evaluation of MV apparatus is pivotal in allowing the proper surgical planning, as well as the screening for trans catheter-based treatment when surgery is not indicated. Aim: The aim of the present review is to describe the crucial role of both Transthoracic Echocardiography (TTE) and Transesophageal Echocardiography (TEE) in the decisional process and the guidance of MV repair procedures. TTE is the main investigation and the first approach used to make diagnosis of MR, to assess the severity and to describe the underlying mechanism, while TEE, especially with 3D echocardiography, has been shown to be useful for clarifying complicated valvular anatomy, assessing the surgical result and detecting complications. The surgical treatment of MR takes advantage of ultrasound evaluation of MV apparatus at any stage of the process, thus making the link between surgery and echocardiography unbreakable throughout the perioperative phase.

Mitral Valve Prolapse: Multimodality Imaging and Genetic Insights

Mitral valve prolapse (MVP) is a common heritable valvulopathy affecting approximately 2.4% of the population. It is the most important cause of primary mitral regurgitation (MR) requiring surgery. MVP is characterized by fibromyxomatous changes and displacement of one or both mitral leaflets into the left atrium. Echocardiography represents the primary diagnostic modality for assessment of MVP. Accurate quantitation of ventricular volumes and function for surgical planning in asymptomatic severe MR can be provided with both echocardiography and cardiac magnetic resonance. In addition, assessment of myocardial fibrosis using late gadolinium enhancement and T1 mapping allows better understanding of the impact of MVP on the myocardium. Imaging in MVP is important not only for diagnostic and prognostic purposes, but is also essential for detailed phenotyping in genetic studies. Genotype-phenotype studies in MVP pedigrees have allowed the identification of milder, non-diagnostic MVP morphologies by echocardiography. Such morphologies represent early expression of MVP in gene carriers. This review focuses on multimodality imaging and the phenotypic spectrum of MVP. Moreover, the review details the recent genetic discoveries that have increased our understanding of the pathophysiology of MVP, with clues to mechanisms and therapy.

Role of modern 3D echocardiography in valvular heart disease

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

Two and three dimensional echocardiography for pre-operative assessment of mitral valve regurgitation

Mitral regurgitation may develop when the leaflets or any other portion of the apparatus becomes abnormal. As the repair techniques for mitral valve disease evolved, so has the need for detailed and accurate imaging of the mitral valve prior to surgery in order to better define the mechanism of valve dysfunction and the severity of regurgitation. In patients with significant mitral valve disease who require surgical intervention, multiplane transesophageal echocardiogram (TEE) is invaluable for surgical planning. However, a comprehensive TEE in a patient with complex mitral valve disease requires great experience and skill. There is evidence to suggest that 3D echocardiography can overcome some of the limitations of 2D multiplane TEE and thus is crucial in evaluation of patients undergoing mitral valve surgery. In the following sections, we review some of the crucial 2D and 3D echo images necessary for evaluation of MR based on the Carpentier classification.

Multiplanar reconstruction of three-dimensional transthoracic echocardiography improves the presurgical assessment of mitral prolapse

BACKGROUND

The aim of this study was to evaluate the value and accuracy of multiplanar reconstruction (MPR) of three-dimensional (3D) transthoracic echocardiographic data sets in assessing mitral valve pathology in patients with surgical mitral valve prolapse (MVP).

METHODS

Sixty-four patients with surgical MVP and preoperative two-dimensional (2D) and 3D transthoracic echocardiography were analyzed. The descriptions obtained by 3D MPR and 2D were compared in the context of the surgical findings.

RESULTS

Two-dimensional echocardiography correctly identified the prolapsing leaflets in 32 of 64 patients and 3D MPR in 46 of 64 patients (P=.016). Among the 27 patients with complex pathology (ie, more than isolated middle scallop of the posterior leaflet prolapse), 3D MPR identified 20 correctly, as opposed to 6 with 2D imaging (P<.001).

CONCLUSION

Interpretation of 3D transthoracic echocardiographic images with MPR improved the accuracy of the description of the MVP compared with 2D interpretation. This added value of 3D MPR was most important in extensive and/or commissural prolapse.

Accuracy of real-time 3-dimensional echocardiography in the assessment of mitral prolapse. Is transesophageal echocardiography still mandatory?

BACKGROUND

Segmental analysis in mitral prolapse is important to decide the chances of valvular repair. Multiplane transesophageal echocardiography (TEE) is the only echocardiographic tool validated for this aim hitherto. The aim of the study was to assess if segmental analysis can be performed with transthoracic real-time 3-dimensional (3D) echocardiography as accurately as with TEE, hence representing a valid alternative to TEE.

METHODS

Forty-one consecutive patients diagnosed with mitral prolapse underwent TEE and a complete 3D echocardiography study, including parasternal and apical real-time; apical full-volume; and 3D color full-volume. Investigators performing TEE were blinded to the 3D results.

RESULTS

Three-dimensional echocardiogram was feasible in 40 to 41 patients (97.7%). Ages ranged from 15 to 92 years, and all possible anatomical patterns of prolapse were represented. Thirty-seven patients (90.2%) had mitral regurgitation of any degree. The level of agreement was k = 0.93 (P < or = .0001), sensitivity of 96.7%, specificity of 96.7%, likelihood ratio for a positive result of 29.0%, and likelihood ratio for a negative result of 0.03%. Four false positives were found, corresponding to scallops A2 (1), A3 (2), and P3 (1). Four false negatives were found, corresponding to scallops A1 (2) and P1 (2). Sensitivity and specificity in the scallop P2 were 100%.

CONCLUSION

Segmental analysis in mitral prolapse can be performed with transthoracic real-time 3D echocardiography as accurately as with TEE. False negatives tend to appear around the anterolateral commissure, whereas false positives tend to appear around the posteromedial commissure. Highest accuracy was reached in central scallops.

Multiplanar visualization in 3D transthoracic echocardiography for precise delineation of mitral valve pathology

A novel multiplanar reformatting (MPR) technique in three-dimensional transthoracic echocardiography (3D TTE) was used to precisely localize the prolapsed lateral segment of posterior mitral valve leaflet in a patient symptomatic with mitral valve prolapse (MVP) and moderate mitral regurgitation (MR) before undergoing mitral valve repair surgery. Transesophageal echocardiography was avoided based on the findings of this new technique by 3D TTE. It was noninvasive, quick, reproducible and reliable. Also, it did not need the time-consuming reconstruction of multiple cardiac images. Mitral valve repair surgery was subsequently performed based on the MPR findings and corroborated the findings from the MPR examination.

Live/real-time three-dimensional transthoracic assessment of mitral regurgitation and mitral valve prolapse

Evaluation of the mitral valve requires appreciation of its complex geometry. To accurately guide surgical interventions and describe pathology, three-dimensional transthoracic echocardiography (TTE) is an immense improvement over the cumbersome mental reconstruction required by two-dimensional approaches. Here we describe real-time, three-dimensional transthoracic techniques for assessing mitral regurgitation and mitral valve prolapse.

The evaluation of real-time 3-dimensional transthoracic echocardiography for the preoperative functional assessment of patients with mitral valve prolapse: a comparison with 2-dimensional transesophageal echocardiography

OBJECTIVE

We sought to compare the feasibility and accuracy of transthoracic real-time 3-dimensional echocardiography (RT-3DE) with transesophageal echocardiography (TEE) for the preoperative functional assessment of patients with mitral valve prolapse.

METHODS

In 44 patients with severe mitral regurgitation caused by type 2 valve dysfunction, TEE and RT-3DE were performed 24 hours before surgery and analyzed by two separate observers. TEE and RT-3DE images were acquired digitally and stored for offline analysis. The echocardiographic results were validated intraoperatively.

RESULTS

Five patients did not have image quality suitable for analysis with RT-3DE and were excluded from analysis, leaving a sample size of 39. In total, 54 of 334 analyzed mitral valve segments were diseased. Prolapse of a single mitral valve segment was present in 25 patients and 14 patients had complex disease involving two or more segments. Sensitivity, specificity, and accuracy for TEE in identification of diseased segments were 94%, 100%, and 96%, respectively. The same values for RT-3DE were 91%, 100%, and 94%, respectively. The differences were not statistically significant. Accuracies were not significantly different according to segment location. Interobserver agreement was 92% for TEE and 88% for RT-3DE (P = nonsignificant).

CONCLUSIONS

RT-3DE is feasible with comparative accuracy to TEE for precise anatomic localization of prolapsing mitral valve segments. However, the technique is limited by poor image quality in 11% of patients.

[Three-dimensional echography: cardiovascular applications]

Real-time three-dimensional echocardiography is currently used in a standard echocardiographic examination. Volume-rendered images better identify and locate anatomic structures and improve our comprehensive approach to various heart diseases. The assessment of mitral valve disease and congenital cardiopathies and the measurement of left ventricular mass, volume, and ejection fraction are the three main applications of three-dimensional echocardiography. Three-dimensional vascular imaging is an emerging and promising application of three-dimensional echography. The near future of three-dimensional echography requires the integration of all modalities of conventional echography in three dimensional probes, a higher image resolution compared to the current situation, as well as the development of real-time three-dimensional probes dedicated to transesophageal cardiac or vascular examination.

Comparison of three-dimensional imaging to transesophageal echocardiography for preoperative evaluation in mitral valve prolapse

Transesophageal echocardiography (TEE) is not optimally suited for recognizing which valve segments are involved in type II mitral valve dysfunction. This study was conducted to compare the diagnostic value of TEE and 3-dimensional image reconstruction (3DIR) in the assessment of Carpentier type II mitral valve lesions. In 74 patients (mean age 59+/-13 years) with mitral regurgitation due to type II valve dysfunction, TEE and 3DIR were performed and analyzed by 2 experts before surgical repair. Leaflet scallops and commissures were displayed in short-axis en face and long-axis views. Echocardiographic results were surgically validated. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated, broken down by valve segments and Barlow's disease. Interobserver variability was also determined. Compared with TEE, 3DIR was superior with respect to sensitivity, positive and negative predictive values, and accuracy, although not always significantly (p<0.05). Specificity was higher for P2 lesions. The clearest advantage of 3DIR over TEE was higher sensitivity in commissural and bileaflet defects (p<0.05). Interobserver agreement on 3DIR was stronger than on TEE results (kappa values 0.52 vs 0.82, p<0.0001). There were 16 disagreements (23%) on TEE but only 5 (7%) on 3DIR readings. In conclusion, the more complex the lesion, the more valuable 3DIR is compared with TEE. Before repair, 3DIR is beneficial for the evaluation and classification of the specific pathology in type II mitral valve dysfunction.

Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Identification of Individual Segment/Scallop Prolapse of the Mitral Valve

In this report, we present 34 patients in whom surgical intervention was undertaken for severe mitral insufficiency due to mitral valve prolapse (MVP). Location and severity of MVP and regurgitation were assessed preoperatively by live/real time three-dimensional transthoracic echocardiography and closely agreed with the surgical findings.

Three-dimensional echocardiography for planning of mitral valve surgery: Current applicability?

BACKGROUND

Two-dimensional transesophageal echocardiographic (2D TEE) assessment of the mitral valve requires mental integration of a limited number of 2D imaging planes. Structural display in three dimensions from any perspective may be of advantage to the surgeon for better judgment and planning.

METHODS

Feasibility, accuracy, and limitations of preoperative three-dimensional transesophageal echocardiography (3D TEE) was assessed in 51 patients with mitral valve disease. The width of the anterior mitral valve was measured with either method and compared with the operative finding. Three-dimensional dynamic sequences of the reconstructed mitral valve were shown preoperatively to the surgeon and later compared with the intraoperative finding.

RESULTS

The quality of the 3D reconstruction was graded as good in 25 patients (49.0%), fair in 16 patients (31.4%), and poor in 10 patients (19.6%) where atrial fibrillation did not allow ECG gating. Thirty-nine patients had successful mitral valve repair and twelve patients required valve replacement. Based on intraoperative findings, sensitivity for the diagnosis of mitral valve prolapse using 2D TEE and 3D TEE was 97.7% and 92.9% (p = ns) respectively and specificity was 100% by both methods. Sensitivity for the diagnosis of rupture of chordae tendineae using 2D TEE and 3D TEE was 92.3% and 30.8% respectively (p < 0.05) and specificity was 100% by both methods.

CONCLUSIONS

Dynamic 3D echocardiography is feasible and can provide good insight into valvular motion and allows adequate preoperative planning when reconstruction is being considered. However dynamic 3D reconstruction is currently limited by the quality of the original 2D echo cross sectional images which can be adversely affected by minimal patient movements, breathing, or cardiac arrhythmia, thus limiting accuracy of the 3D TEE significantly compared with 2D TEE.

A method for the morphological analysis of the regurgitant mitral valve using three dimensional echocardiography

BACKGROUND

Atrial en-face reconstructions are commonly used to assess mitral valve morphology in three dimensional (3D) echocardiography but may miss important abnormalities.

OBJECTIVE

To present a systematic method for the analysis of the regurgitant mitral valve using a combination of en-face and longitudinal views for better anatomical evaluation.

METHODS

Detailed 3D assessment was done on 58 patients undergoing mitral valve repair. En-face and longitudinal views were compared for detection and location of primary pathology. The quality of acquisitions under general anaesthesia and sedation was also compared.

RESULTS

Recognition of valve structure was significantly better with longitudinal reconstruction for both mitral leaflets but not for the commissures. Accurate identification of pathology was possible in 95% cases, compared with 50% for en-face reconstruction (p < 0.001). There was no significant difference between imaging under sedation and anaesthesia.

CONCLUSION

En-face reconstructions alone are inadequate. Additional longitudinal reconstructions are necessary to ensure full inspection of valve morphology.

Pointwise assessment of three-dimensional computer reconstruction of mitral leaflet surfaces from rotationally scanned echocardiograms in vitro

Three-dimensional transesophageal echocardiography offers promise for improved understanding of mitral leaflet pathology, but it has not been validated quantitatively, nor has the minimum number of imaging planes for satisfactory reconstruction been determined with a rotational scanning geometry. This study assessed its accuracy in vitro by comparing, on a 1 x 1-mm grid, the surfaces of mitral leaflets derived from 5-degree rotational ultrasonic scans with those derived from laser scans of casts of the atrial side of the leaflets. Overall, the ultrasonically derived surface had a mean absolute deviation of 0.65 +/- 0.12 mm from the laser-derived surface. Using only alternate imaging planes (10-degree increments) made no significant difference in the overall distribution of deviations (P =.56), although the distributions on some individual specimens differed markedly. We conclude that 5-degree rotational scanning in vitro can reconstruct the mitral valve leaflets with sufficient accuracy and detail to render clinically important features.

Usefulness of transesophageal three-dimensional echocardiography in the identification of individual segment/scallop prolapse of the mitral valve

We evaluated the potential usefulness of three-dimensional (3D) transesophageal echocardiography (TEE) in assessing individual scallop/segment prolapse in 36 adult patients with mitral valve prolapse (MVP) undergoing surgical correction. Intraoperative 3D TEE correctly identified the location of scallop/segment prolapse in 34 of 36 patients (94%). However, in 6 of these patients 3D TEE images revealed more scallops or segments with prolapse than the surgeon noted intraoperatively. Prolapse of these areas was less prominent and this could possibly explain the lack of correlation with the surgical findings in these patients. In another 2 patients areas of prolapse seen by the surgeon were missed by 3D TEE because some of those scallops/segments could not be well imaged due to image "drop out" and artifacts. Thus, perfect correlation between 3D TEE and surgery was noted in 28 of 36 (78%) patients. Noncoaptation of the MV was also identified in 2 patients. The prolapsed area of posterior (n = 28 observations) and anterior (n = 9 observations) MV leaflets ranged from 1 cm2 to 9 cm2 (mean 3.50 cm2+/- 2.14) and 1.20 cm2 to 5.99 cm2 (mean 3.21 cm2+/- 1.33), respectively. Interobserver and intraobserver agreement for location and area of MVP was excellent (r = 0.97 and r = 0.99, respectively; all P values are <0.0001). In conclusion, 3D TEE is useful in identifying the location of MVP. It may also be potentially useful in assessing the extent of individual scallop/segment prolapse and identifying sites of MV noncoaptation. This information could aid the surgeon in deciding the extent of MV resection.

Evaluation of mitral valve prolapse using newly developed real-time three-dimensional echocardiographic system with real-time volume rendering

The development of a real-time three-dimensional (RT3D) image acquisition system and direct digital links between ultrasound equipment and the data processing computer facilitate improved 3D image reconstruction. However, at present time, it is hard to promptly display 3D images and is also ineffective for a practical use. The objective of this study was to assess the feasibility of a new transthoracic RT3D echocardiographic system for evaluation of mitral valve prolapse. Eighteen patients with mitral valve prolapse diagnosed by transthoracic two-dimensional (2D) echocardiography and M-mode were examined through this technique (11 male, mean age 42 +/- 17 years). Since visualization of mitral valve from apical four-chamber view was better than that of the parasternal approach, only apical approach was used for mitral valve evaluation. This system is capable of acquiring volumetric data from mechanical scanning of the phased-array transducer (3.5 MHz) as well as displaying the volume rendered images of the structure without storing the image data and reconstruction of the object. The prolapse of leaflet could be seen in 14/ 18 (77%) of patients with mitral valve prolapse based on conventional echocardiography. The newly developed transthoracic RT 3D ultrasound system without a reconstruction process seemed to be a useful noninvasive tool for diagnosis of mitral valve prolapse and detection of prolapsed leaflet or scallop, which is very important for deciding on a reliable surgical technique.

Successful three-dimensional reconstruction using transesophageal echocardiography in a patient with a left atrial myxoma

Two-dimensional echocardiography can provide intracardiac images. However, the cross-sectional images require mental reconstruction to understand a three-dimensional intracardiac structure. It is sometimes hard for inexperienced echocardiographers to engage in reconstruction. Thus, three-dimensional echocardiography is potentially beneficial because these images can provide extra information without mental reconstruction. Herein we demonstrate three-dimensional reconstruction using transesophageal echocardiography in a patient with a left atrial myxoma. It contributed to clarifying the surgical considerations, including whether the tumor was adhering to the left atrium or the mitral valve.

Recent advances in echocardiographic evaluation of left ventricular anatomy, perfusion, and function

This article provides a brief overview of several recently developed, emerging technologies and discusses their potential uses on clinical grounds. These new technologies include three-dimensional imaging, objective automated evaluation of ventricular function with acoustic quantification, assessment of regional ventricular performance using color kinesis and tissue Doppler imaging, harmonic imaging, and power Doppler imaging. Our hope is that readers will gain a better understanding of the principles underlying these technological advances, which will help them to integrate these new techniques efficiently into their clinical practices.

In vitro simulation and quantification of temporal jitter artifacts in ECG-gated dynamic three-dimensional echocardiography

The image quality of dynamic 3-D echocardiography is limited by temporal jitter artifacts that result from the asynchronous acquisition of video frames with the cardiac cycle. This paper analyzes the source and extent of these artifacts using in vitro studies. Dynamic 3-D images of a myocardial motion phantom were reconstructed and analyzed for eight cardiac motion patterns. The extent of temporal jitter artifacts was quantified, first, from the images by computing temporal jitter maps and, second, predicted from the motion waveforms. Temporal jitter appeared as a pattern of streak artifacts converging at the axis of rotation of the imaging plane, for the rotational scanning approach used in our study. The results of the experimental analysis techniques were compared with the waveform analysis using linear regression analysis. The least squares line showed good correlation between the data (r > 0.9) and its deviation from the line of identity was calculated to be <9%.

Three-dimensional transesophageal echocardiography (TEE) and other future directions

As faster imaging systems enter the market, three-dimensional echocardiography is gearing up to become a useful tool in assisting the clinician to image the heart in many innovative projections. What started out as a novel idea of displaying a three-dimensional anatomic picture of the heart now provides a multitude of views of the heart and its structures. Information gained from anatomic and dynamic data has helped clinicians and surgeons in making clinical decisions. In the future, this imaging modality may become a routine imaging modality for assessing cardiac pathology and may serve to increase understanding of the dynamics of the heart.

Three-dimensional echocardiography using a muliplane transesophageal probe: the clinical applications

The use of multiplane transesophageal echocardiography has provided three-dimensional image sets of the heart from multiple two-dimensional images with high-image quality through rotation of the transducer without changing its position (rotational scanning). We discuss the methods, clinical applications, and current limitations of this three-dimensional technique.

Three-dimensional echocardiography paves the way toward virtual reality

The heart is a three-dimensional (3-D) object and, with the help of 3-D echocardiography (3-DE), it can be shown in a realistic fashion. This capability decreases variability in the interpretation of complex pathology among investigators. Therefore, it is likely that the method will become the standard echocardiography examination in the future. The availability of volumetric data sets allows retrieval of an infinite number of cardiac cross-sections. This results in more accurate and reproducible measurements of valve areas, cardiac mass and cavity volumes by obviating geometric assumptions. Typical 3-DE parameters, such as ejection fraction, flow jets, myocardial perfusion and LV wall curvature, may become important diagnostic parameters based on 3-DE. However, the freedom of an infinite number of cross-sections of the heart can result in an often-encountered problem of being "lost in space" when an observer works on a 3-DE image data set. Virtual reality computing techniques in the form of a virtual heart model can be useful by providing spatial "cardiac" information. With the recent introduction of relatively low cost portable echo devices, it is envisaged that use of diagnostic ultrasound (US) will be further boosted. This, in turn, will require further teaching facilities. Coupling of a cardiac model with true 3-D echo data in a virtual reality setting may be the answer.

[Echocardiographic evaluation in unoperated congenital heart disease in adults]

Echo and Doppler echocardiographic procedures have gained special importance in the diagnostics of congenital diseases in adults. These procedures permit detailed visualization of the pathomorphology of the heart as well as reliable evaluation of the hemodynamic changes. There are differentiated indications for the various procedures, such as transthoracic and transesophageal echocardiography, Doppler and color-Doppler echocardiography, contrast echocardiography and 3-dimensional echocardiography. This article discusses the opposition of the various echo and Doppler echocardiographic procedures with respect to the diagnostics of the most frequent non-operated congenital diseases in adults. The pathomorphology of the various congenital diseases will be summarized and then the important echocardiographic criteria presented which are decisive for the diagnostic procedure. In simple congenital malformation of cardiac valves, such as bicuspid aortic valve (Figure 1: aortic ring abscess), pulmonary valve stenosis (Figure 2), Ebstein's anomaly (Figure 3) or malformations of the mitral valve (Figure 4: cleft in the anterior mitral cusp), the diagnosis can often be made using transthoracic echo and Doppler echocardiography, and the severity of the defect determined. However, the sonographic conditions, especially in adults, are frequently too limited to permit recognition of detailed smaller changes, so that transesophageal examination is required to finally confirm the diagnosis in these patients. In the diagnostics of diseases of the left ventricular outflow tract and the thoracic aorta, such as subvalvular aortic valve stenosis (Figure 5), the sinus of Valsalva aneurysm or the coarctation of the aorta (Figure 6), the left ventricular outflow tract can be evaluated morphologically from a transthoracic procedure and the accelerations of flow can be recorded by continuous wave Doppler. If there is no sclerosis of the fibrous membrane, these can often not be depicted by transthoracic procedures, so that a supplementary transesophageal examination is meaningful. This is required in any case for diseases of the descending thoracic aorta. In the case of congenital lesions, such as atrial septal defects (Figure 7: anomalous pulmonary venous return, Figure 8: 3-dimensional visualization of an atrial septal defect, Figure 9: sinus venosus defect), ventricular septal defect or a patent ductus arteriosus Botalli (Figure 10), color-Doppler and contrast echocardiography have become especially important. Transesophageal examination is also indicated for these congenital diseases for direct depiction of the defect as well as for precise evaluation of the shunt. Moreover, in atrial septal defects, it has been shown that a 3-dimensional echocardiography provides additional advantage with respect to spatial relationship of the defect to the other cardiac structures, as well as presenting dynamic changes during a heart cycle. Extensive knowledge of complex congenital heart disease, such as tetralogy of Fallot (Figure 11), complete transposition of the great arteries, congenitally corrected transposition of the great arteries (Figure 12), the double-outlet right ventricle, truncus arteriosus communis, the cor triatriatum, tricuspid atresia (Figure 13) or the univentricular heart (Figure 14) usually requires performance of a transthoracic echo- and Doppler echocardiographic examination to assess the pathomorphological changes and to examine hemodynamics. In the majority of patients, supplementary transesophageal echocardiography and an echo contrast examination are important. Initial examinations using 3-dimensional echocardiography are very promising in this connection and with respect to the exact spatial presentation of pathoanatomical structures.

Real-time, 3-dimensional echocardiography acquires all standard 2-dimensional images from 2 volume sets: a clinical demonstration in 45 patients

To test the hypothesis that real-time, 3-dimensional (3-D) echocardiography can obtain all standard 2-dimensional (2-D) views from acquisition of 2 volume sets, we scanned 45 patients (24 men, 21 women; mean age 49 +/- 17 years). This real-time 3-D device (VOLUMETRICS Medical Imaging, Durham, NC) uses a matrix phased array transducer in a 60 degree pyramidal volume. Images are displayed as 2 steerable, intersecting, conventional 2-D image sectors that can be oriented throughout 3-D space. By using this equipment, we were able to obtain 93.3% of standard views from a parasternal volume set and 85.2% of standard views from an apical volume set. The mean scanning time was 91 +/- 19 seconds for the parasternal volume set and 86 +/- 22 seconds for the apical volume set. We conclude that standard 2-D views can be obtained in the majority of patients by using this method. This equipment has the potential to substantially decrease the imaging time compared with the standard 2-D echocardiography.

Evaluation of the mitral annulus by extracted three-dimensional images in patients with an annuloplasty ring

We evaluated the capability of extracted 3-dimensional images obtained by multiplane transesophageal echocardiography in the evaluation of nonplanarity and area change of the mitral annulus in patients with an annuloplasty ring. This method is feasible in the evaluation of nonplanarity and area change of mitral annulus in patients with an annuloplasty ring.