Real-time 3-dimensional echocardiographic imaging of congenital heart disease using matrix-array technology: freehand real-time scanning adds instant morphologic details not well delineated by conventional 2-dimensional imaging

Feasibility and accuracy of real-time three-dimensional echocardiography in evaluating the aortic valve in children

Background

Aortic valve assessment by 2D transthoracic echocardiography is a relatively complex task owing to the unique anatomical features of the left ventricular outflow tract and its dynamic nature. We aimed to evaluate the accuracy of 3D transthoracic echocardiography [3D TTE] in assessing the aortic valve in children.

Results

The first group included 11 males and six females, with a mean age of 5.76 ± 6.39 years. All of these patients had aortic valve disease with a bicuspid variant. The second group included seven males and seven females, with a mean age of 4.4 ± 4.05 years. All of these patients had normal aortic valve morphology and had another congenital cardiac anomaly. The aortic valve annulus was assessed using the three modalities; 2D, 3D echocardiography in the vertical and horizontal diameters, and angiography. The aortic valve area was measured by 2D and 3D echocardiography using multiplane reformatted mode. The results of the analysis were then compared. They revealed that 3D echocardiographic measurement of the aortic annulus (horizontal diameter) correlated better with angiography than 2D and 3D (vertical diameter) echocardiographic measurements. There was a significant difference between the aortic valve area measured by 2D echocardiography and that measured by 3D echocardiography among the two groups, 2D echocardiography seems to underestimate the true aortic valve area.

Conclusion

The study concluded that 3D TTE with multiplane reformatted mode allows a more accurate assessment of the aortic valve when compared to 2D echocardiography and this correlates better with the angiographic findings.

Usefulness of the multiplanar reformatting mode of three-dimensional echocardiography in evaluating valvular and structural heart disease: An experience from Saudi Arabia

OBJECTIVE

The aim of this study is to compare the feasibility and capacity of multiplanar reformatting (MPR) mode of three-dimensional echocardiography (3DE-MPR technique) with two-dimensional echocardiography (2DE) for visualizing morphological details during evaluation of congenital heart disease (CHD). The study also seeks to validate the accuracy of 3DE MPR in determining cardiac valvular lesions and the application of the 3DE-MPR technique in daily clinical practice.

METHODS

A cross-sectional study was carried out at Madinah Cardiac Centre, Saudi Arabia from May to December 2012. Various forms of CHD were diagnosed in 43 patients by conventional 2DE, and the patients were then examined with the 3DE-MPR technique using dedicated software and a standard protocol.

RESULTS

Of the 43 patients, 23 (53.5%) were males and 20 (46.5%) females. Their age varied from 30 days to 146 months (mean age, 70.2 months and SD = 42.5 months) and their weight from 4 to 42 kg (mean weight, 20.2 kg and SD = 9.7 kg). The 2DE showed left heart lesions in nine patients (20.9%), right heart lesions in 23 (53.5%), atrial septal defects in five (11.6%) and complex CHD in six patients (14%). The 3DE MPR technique application and analysis was possible in all patients. The study demonstrated the fields where 3DE MPR was of additive value to conventional 2DE for the vena contracta area in valvular regurgitation severity and the planimetry for the valvular stenosis precise estimation, enface views of atrial septal defects with direct visualisation of shape and size of the defect, and segmental analysis of complex CHD using one window. The clinician and surgeon were then able to determine the mechanism and severity of the lesions and thus decide on appropriate treatment and management.

CONCLUSION

The study demonstrated the usefulness of 3DE-MPR as a complement to conventional 2DE. The technique is a significant technological breakthrough that allows instant visualization of morphological details and precise determination of cardiac valvular lesions, which were less clearly delineated by 2DE alone.

Current clinical applications of transthoracic three-dimensional echocardiography

The advent of three-dimensional echocardiography (3DE) has significantly improved the impact of non-invasive imaging on our understanding and management of cardiac diseases in clinical practice. Transthoracic 3DE enables an easier, more accurate and reproducible interpretation of the complex cardiac anatomy, overcoming the intrinsic limitations of conventional echocardiography. The availability of unprecedented views of cardiac structures from any perspective in the beating heart provides valuable clinical information and new levels of confidence in diagnosing heart disease. One major advantage of the third dimension is the improvement in the accuracy and reproducibility of chamber volume measurement by eliminating geometric assumptions and errors caused by foreshortened views. Another benefit of 3DE is the realistic en face views of heart valves, enabling a better appreciation of the severity and mechanisms of valve diseases in a unique, noninvasive manner. The purpose of this review is to provide readers with an update on the current clinical applications of transthoracic 3DE, emphasizing the incremental benefits of 3DE over conventional two-dimensional echocardiography.

Visualization of patent ductus arteriosus using real-time three-dimensional echocardiogram: Comparative study with 2D echocardiogram and angiography

PURPOSE

To determine the feasibility and accuracy of real time 3D echocardiography (RT3DE) in determining the dimensions and anatomical type of the patent ductus arteriosus (PDA).

METHODS

The study included 42 pediatric patients with a mean age of 3.6 years (ranging from 2 months to 14 years) who were referred for elective percutaneous PDA closure. All patients underwent full 2D echocardiogram as well as RT3DE with off line analysis using Q lab software within 6 h from their angiograms. The PDA was studied as regard the anatomical type, length of the duct as well as the ampulla and the pulmonary end of the PDA. Data obtained by RT3DE was compared against 2D echocardiogram and the gold standard angiography.

RESULTS

Offline analysis of the PDA was feasible in 97.6% of the cases while determination of the anatomical type using gated color flow 3D acquisitions was achieved in 78.5% of the cases. The pulmonary end of the duct was rather elliptical using 3D echocardiogram. There was significant difference between the pulmonary end measured by 3D echocardiogram and angiography (P < 0.001). There was no significant difference between either the length or the ampulla of the PDA measured by 3D echocardiogram and that measured by angiography (P value = 0.325 and 0.611, respectively). There was a good agreement between both 2D or 3D echocardiogram and angiography in determining the anatomical type of the PDA (K = 0.744 and 0.773, respectively). However 3D echocardiogram could more accurately determine type A and type E ductus compared to 2D echocardiogram.

CONCLUSION

3D echocardiogram was more accurate than 2D echocardiogram in determining the length and the ampulla of the PDA. The morphologic assessment of the PDA using gated 3D color flow was achieved in 78.5% of the patients. Nevertheless the use of 3D echocardiogram in assessment of small vascular structures like PDA in children with rapid heart rates is still of limited clinical value.

Recognition of a cleft mitral valve utilizing real-time three-dimensional transoesophageal echocardiography

We present a case in which real-time three-dimensional transoesophageal echocardiography was utilized to obtain better understanding of a cleft mitral valve. Additionally, the embryological development of a cleft mitral valve will be reiterated.

Atrioventricular Valve Morphology and Dynamics in Congenital Heart Disease as Imaged with Real-time 3-Dimensional Matrix-array Echocardiography: Comparison with 2-Dimensional Imaging and Surgical Findings

OBJECTIVE

We sought to describe our initial experience with real-time 3-dimensional echocardiographic (RT3DE) imaging of atrioventricular valve (AVV) anomalies in pediatric patients to resolve a specific morphologic or dynamic detail, which, although suggested, could not be well resolved during the conventional 2-dimensional (2D)/Doppler examination.

METHODS

In all, 41 patients (age range 1 day-24 years) with different AVV anomalies underwent RT3DE as part of their comprehensive echocardiographic assessment. Matrix-array transducers with a frequency range of 1 to 4 MHz were used. The first 27 patients were not consecutive, and the RT3DE findings interpreted by one examiner were compared directly with the 2D findings interpreted by a different examiner. In the following consecutive 14 patients, the RT3DE findings were compared with the surgical findings and with the interpretations of their corresponding 2D examinations by 3 examiners who were blinded to the findings of RT3DE for more objective comparison.

RESULTS

RT3DE imaging was successful in resolving the raised question in all patients. The morphology of the valve leaflets and their chordal attachments, the mechanism and origin of regurgitation, and the geometry of the regurgitant volume were well delineated by RT3DE imaging. In the second group of patients, there was agreement between the morphologic details delineated by RT3DE (a total of 21 specific questions raised) and the surgical findings in those patients who had immediate surgery. On the other hand, RT3DE showed prominent AVV chordal attachments in the left ventricular outflow tract in one patient, which was not considered surgically relevant during the repair.

CONCLUSIONS

Although RT3DE is still in its initial phase, has some technical limitations, and does not change the basic diagnosis made by 2D imaging, echocardiographic examination using the matrix-array transducer is a useful adjunct in delineating specific morphologic and dynamic details of the AVV in congenital heart disease.

Three-Dimensional Echocardiography in Congenital Heart Disease

Matrix array technology has brought three-dimensional echocardiography into the clinical practice of cardiology. Arguably, this advancement is most notable in the field of pediatric cardiology. Full-volume acquisitions now can be undertaken in the youngest of infants with excellent image quality. This article illustrates the clinical application of three-dimensional echocardiography in congenital heart disease.

Real-time three-dimensional echocardiography: technological gadget or clinical tool?

The complex anatomy of cardiac structures requires three-dimensional spatial orientation of images for a better understanding of structure and function, thereby improving image interpretation. Real-time three-dimensional echocardiography is a recently developed technique based on the design of an ultrasound transducer with a matrix array that rapidly acquires image data in a pyramidal volume. The simultaneous display of multiple tomographic images allows three-dimensional perspective and the anatomically correct examination of any structure within the volumetric image. As a consequence, it is less operator-dependent and hence more reproducible. Dedicated software systems and technologies are based on high-performance computers designed for graphic handling of three-dimensional images by providing possibilities beyond those obtainable with echocardiography. This methodology allows simultaneous display of multiple superimposed planes in an interactive manner as well as a quantitative assessment of cardiac volumes and ventricular mass in a three-dimensional format without a pre-established assumption of cardiac chamber geometry. In addition, myocardial contraction and/or perfusion abnormalities are clearly identified. Finally, real-time three-dimensional colour Doppler flow mapping enables complete visualisation of the regurgitant jet and new ways of assessing regurgitant lesion severity. Thus, this technique expands the abilities of non-invasive cardiology and may open new doors for the evaluation of cardiac diseases. In this article, current and future clinical applications of real-time three-dimensional echocardiography are reviewed.

Illustration of the Additional Value of Real-time 3-dimensional Echocardiography to Conventional Transthoracic and Transesophageal 2-dimensional Echocardiography in Imaging Muscular Ventricular Septal Defects: Does This Have Any Impact on Individual Patient Treatment?

OBJECTIVE

We sought to answer the question of whether the additional morphologic details obtained by real-time 3-dimensional (3D) echocardiographic (RT3DE) imaging of muscular ventricular septal defect (VSD) has any significant impact on treatment options of individual patient.

BACKGROUND

Muscular VSD can be safely and effectively closed by interventional catheterization procedure using VSD devices under transesophageal echocardiographic (TEE) guidance. Recent application of RT3DE has shown great promise for imaging VSD with better display of the exact geometry, size, and location of the defect.

METHODS

Nineteen patients with different types of VSDs were imaged with RT3DE matrix-array transducer; there were 6 cases with muscular VSD. Based on standard transthoracic echocardiographic and TEE imaging, one patient was considered a good candidate for perventricular VSD device occlusion, three patients were considered for surgical closure, and in two patients no intervention was deemed necessary.

RESULTS

RT3DE successfully displayed the exact morphology of the VSD in all 6 patients, whereas transthoracic echocardiography and TEE showed the defect as a dropout with variable diameter in different views. Such planer images did not accurately predict the exact morphology in the patient in whom device occlusion was considered and the device embolized to the left ventricle in a few heartbeats. Surgical circular patch was used in two patients and primary suture was used in two patients in agreement with the 3D morphology. In two patients the 3D morphology of the VSD was small enough that no intervention was considered.

CONCLUSIONS

RT3DE imaging of muscular VSD can accurately display the exact geometry of the defect, which can have significant impact on treatment strategies of individual patients. This new imaging modality should be an important adjunct to the standard transthoracic echocardiographic and TEE imaging of these defect before any intervention.