3D Transesophageal Echocardiographic Images Research Articles

Influence of device generations on alternations of mitral annulus after transcatheter edge-to-edge repair: a real-time three-dimensional transesophageal echocardiography study

Abstract Background Alternation of the mitral annulus (MA) after transcatheter edge-to-edge mitral valve repair (TEER) is reported to be associated with a reduction of mitral regurgitation (MR). However, the influence of the new device system with 4 device size options (MitraClip G4) on MA geometry compared to the conventional device (G2) remains unknown. Methods and results A total of 129 patients (mean age 79±10 years, male 66%) including 38 primary MR and 91 secondary MR who underwent TEER guided with three-dimensional (3D) transesophageal echocardiography (TEE) were included. MA area, anterior-posterior (AP) diameter, inter-commissure (CC) diameter, and MA ellipticity before and after MitraClip implantation were measured using 3D TEE images assessed by dedicated software. MitraClip G4 was used in 54 cases (42%). In patients with secondary MR, greater changes in MA area, AP diameter, and MA ellipticity were observed in patients treated with G4 compared to G2 (P=0.001, 0.003, and 0.39, respectively). In contrast, patients with primary MR had no differences in the change of MA parameters between G2 and G4. Patients with significant residual MR had less increase of MA ellipticity after device implantation in secondary MR (P=0.014), but not in primary MR (P=0.062). Conclusion In patients with secondary MR, MitraClip G4 made greater changes in MAA, AP diameter, and MA ellipticity compared to MitraClip G2, but not in CC diameter. The change of ellipticity was associated with a reduction of MR after device implantation in secondary MR. These findings indicated that MitraClip G4 may lead favorable MA alternation than G2, especially in secondary MR.

Automatic alignment of standard views for transesophageal echocardiographic images.

3D transesophageal echocardiography (TEE) has become an important modality for pre- and peri-operative imaging of valvular heart disease. TEE can give excellent visualization of valve morphology in 3D rendering. As a convention, 3D TEE images are reformatted in three standard views. We describe a method for automatic calculation of parameters needed to define the standard views from 3D TEE images using no manual input. An algorithm was designed to find the center of the mitral valve and the left ventricular outflow tract (OT). These parameters defined the three-chamber view. The problem was modeled as a state estimation problem in which a 3D model was deformed based on shape priors and edge detection using a Kalman filter. This algorithm is capable of running in real time after initialization. The algorithm was validated by comparing the automatic alignments of 106 TEE images against manually placed landmarks. The median error for determining the mitral valve center was 7.1mm, and the median error for determining the left ventricular OT orientation was 13.5deg. The algorithm is an accurate tool for automating the process of finding standard views for TEE images of the mitral valve.

Taking Command of Three-Dimensional Stitching Artifacts: From an Annoyance to an Easy Tool for Navigating Three-Dimensional Transesophageal Echocardiography

Despite many recent advances in three-dimensional (3D) transesophageal echocardiography (TEE) imagining, the process of orienting 3D TEE images is nonintuitive and uses assumptions based on idealized anatomy. Correlating two-dimensional TEE cross-sectional images to 3D reconstructions remains an additional challenge. In this article, we suggest the repurposing of the stitching artifact generated in 2-beat electrocardiogram-gated 3D TEE as a means of exactly orienting 3D images within a patient's unique anatomy. We demonstrate the application of this strategy to assess a normal mitral valve to localize scallops of mitral valve prolapse and to visualize typical left atrial appendage two-dimensional cuts in a 3D space. By taking command of stitching artifacts, cardiac imagers can successfully navigate the complex structures of the heart for optimal, individualized echocardiographic views.

Impact of a one-day three-dimensional transesophageal echocardiography workshop on clinical practice at a single academic centre.

Transesophageal echocardiography (TEE) is a powerful diagnostic tool which has become an integral part in the management of cardiac surgery patients. We developed a one-day 3D TEE workshop specifically designed to meet the needs of perioperative cardiac anaesthesiologists. We hypothesized that participation in the workshop would increase the uptake of 3D TEE in routine perioperative practice. To examine the impact of one-day 3D TEE workshop on 3D TEE image acquisition and incorporation into routine perioperative practice. Tertiary care hospital. Prospective observational monocentric study. A convenience sample of 20 cardiac anesthesiologists (with an option to attend the one- day workshop midway through the study) from a single center consented to have their intraoperative TEE images collected during the course of the study reviewed for research purposes. Images acquired 6 months before, immediately after, and 6 months following the workshop and images were examined by a blinded, expert echocardiographer. Data collected for 16 participants (8 workshop attendees, 8 non-attendees) indicate that the TEE workshop increased the number of 3D TEE images, but not x images acquired immediately following the workshop (P=0.006). No difference was observed in number of 3D images at six months' post workshop. Workshop participants obtained more 3D and multi-plane images after the workshop and more 3D images at 6 months compared to those who did not attend the workshop. Our study suggests that a single day hands-on 3D TEE workshop may have had an impact on the implementation of intraoperative 3D TEE in experienced echocardiographers.

Real-Time Monitoring and Step-by-Step Guidance for Transapical Mitral Valve Edge-to-Edge Repair Using Transesophageal Echocardiography

MitraClip edge-to-edge (E2E) repair system is the only transcatheter device recommended in the current guidelines for treating mitral regurgitation (MR). The percutaneous femoral venous transseptal access of MitraClip requires a complex steerable delivery system and may thus be technically complex to optimally position and deploy the clip onto the mitral valve. A transapical approach for E2E repair has been devised to treat MR for the ease of operation (ValveClamp system, Hanyu Medical Technology, Shanghai). The first-in-human study of ValveClamp has demonstrated its early feasibility and effectiveness for the treatment of patients with degenerative MR. Transesophageal echocardiography (TEE) is the only imaging modality required for intraoperative guidance of ValveClamp implantation. Successful implantation depends on accurate localization and orientation of the clamp and efficient intraoperative communication between the echocardiographer and the intervention team. Thus, the focus of this review is on elaborating how two-dimensional (2D) and three-dimensional (3D) TEE are used in clinical practice to guide ValveClamp implantation and it may facilitate the understanding of simplicity and safety of this novel procedure. We also describe the implementation of several novel advancements in 3D TEE imaging, which improve the confidence of image interpretation for intraoperative guidance and expedite implantation times.

An orifice shape-based reduced order model of patient-specific mitral valve regurgitation

Mitral valve regurgitation (MR) is one of the most prevalent valvular heart diseases. Its quantitative assessment is challenging but crucial for treatment decisions. Using computational fluid dynamics (CFD), we developed a reduced order model (ROM) describing the relationship between MR flow rates, transvalvular pressure differences, and the size and shape of the regurgitant valve orifice. Due to its low computational cost, this ROM could easily be implemented into clinical workflows to support the assessment of MR. We reconstructed mitral valves of 43 patients from 3D transesophageal echocardiographic images and estimated the 3D anatomic regurgitant orifice areas using a shrink-wrap algorithm. The orifice shapes were quantified with three dimensionless shape parameters. Steady-state CFD simulations in the reconstructed mitral valves were performed to analyse the relationship between the regurgitant orifice geometry and the regurgitant hemodynamics. Based on the results, three ROMs with increasing complexity were defined, all of which revealed very good agreement with CFD results with a mean bias below 3% for the MR flow rate. Classifying orifices into two shape groups and assigning group-specific flow coefficients in the ROM reduced the limit of agreement predicting regurgitant volumes from 9.0 ml to 5.7 ml at a mean regurgitant volume of 57 ml.

Utility of Three-Dimensional Transesophageal Echocardiography for Mitral Annular Sizing in Transcatheter Mitral Valve Replacement Procedures: A Cardiac Computed Tomographic Comparative Study

Three-dimensional (3D) transesophageal echocardiographic (TEE) imaging is frequently used as an initial screening tool in the evaluation of patients who are candidates for transcatheter mitral valve replacement (TMVR). However, little is known about the imaging correlation with the gold standard, computed tomographic (CT) imaging. The aims of this study were to test the quantitative differences between these two modalities and to determine the best 3D TEE parameters for TMVR screening. Fifty-seven patients referred to the heart valve clinic for TMVR with prostheses specifically designed for the mitral valve were included. Mitral annular (MA) analyses were performed using commercially available software on 3D TEE and CT imaging. Three-dimensional TEE imaging was feasible in 52 patients (91%). Although 3D TEE measurements were slightly lower than those obtained on CT imaging, measurements of both projected MA area and perimeter showed excellent correlations, with small differences between the two modalities (r=0.88 and r=0.92, respectively, P<.0001). Correlations were significant but lower for MA diameters (r=0.68-0.72, P<.0001) and mitroaortic angle (r=0.53, P=.0001). Receiver operating characteristic curve analyses showed that 3D TEE imaging had a good ability to predict TMVR screening success, defined by constructors on the basis of CT measurements, with ranges of 12.9 to 15cm2 for MA area (area under the curve [AUC]=0.88-0.91, P<.0001), 128 to 139mm for MA perimeter (AUC=0.85-0.91, P<.0001), 35 to 39mm for anteroposterior diameter (AUC=0.79-0.84, P<.0001), and 37 to 42mm for posteromedial-anterolateral diameter (AUC=0.81-0.89, P<.0001). Three-dimensional TEE measurements of MA dimensions display strong correlations with CT measurements in patients undergoing TMVR screening. Three-dimensional TEE imaging should be proposed as a reasonable alternative to CT imaging in this vulnerable population.

P1335 Cor triatriatum sinister: the importance of multimodality imaging

Abstract A 67-year-old woman who had previous history of hypertension and hyperlipidemia was referred to the cardiologist because of nonspecific electrocardiographic abnormalities. During physical exam a systolic murmur was detected. Transthoracic echocardiography (TTE) showed aortic valve sclerosis with no evidence of valvular stenosis. An unexpected finding was the presence of a membrane at left atrium (LA) and a transesophageal echocardiography (TEE) was recommended with suspicion of cor triatriatum. No signs of obstruction to LA flow were demonstrable with pulsed-wave or colour Doppler analysis. On 3D TEE imaging, a structure compatible with a left atrial tendon was visualized. To complete the study computed tomography (CT) was performed, revealing the presence of a real membrane dividing the LA into two components, separating the pulmonary veins from the true LA chamber with the left atrial appendage (LAA), being the patient diagnosed of cor triatriatum. Cor triatriatum sinister (CTS) is a rare but well-recognised form of congenital heart disease. It is believed to reflect failure of incorporation of the common pulmonary vein into the LA. Defining the relationship between the CTS membrane and the LAA allows differentiation from a supra­mitral ring. In CTS, the membrane is located superior to the LAA (between the LAA and pulmonary veins), while a supra­mitral ring is located inferior to the LAA and is often adher­ent to, and constitutes part of, the mitral valve leaflets. The diagnosis of CTS may be made at any age. Most cases involve a nonobstructive membrane, diagnosis of which is facilitated by advances in imaging technology. TTE is adequate to define the clinical relevance of CTS but it may be more precisely tailored with cardiac CT or cardiac magnetic resonance (CMR) imaging. This case emphasizes the importance of a multimodality imaging approach. CTS can present as an isolated lesion, but it is more commonly seen in association with other congenital cardiac anomalies (patent foramen ovale, atrial septal defect, patent ductus arterio­sus, coarctation of the aorta, persistent left superior vena cava, ventricular septal defect, anomalous pulmonary venous drainage, and a variety of left-sided cardiac abnormalities). Nonobstructive asymptomatic adults do not require intervention. However, onset of any cardiovascular symptom should prompt detailed evaluation. A turbulent jet arising from the opening in an obstructive CTS membrane may produce jet lesions on the structurally normal mitral valve causing damage and secondary mitral regurgitation. Surgi­cal resection is the first line of management for an obstructive membrane in the LA. The development of atrial fibrillation in an individual with nonobstructive CTS may also constitute an indication for surgi­cal resection as the presence of the membrane may increase the risk of thromboembolic events. Abstract P1335 Figure. Cor triatriatum sinister (TTE,3D-TEE,CT)

Influence of the Quantity of Aortic Valve Calcium on the Agreement Between Automated 3-Dimensional Transesophageal Echocardiography and Multidetector Row Computed Tomography for Aortic Annulus Sizing

Accurate aortic annulus sizing is key for selection of appropriate transcatheter aortic valve implantation (TAVI) prosthesis size. The present study compared novel automated 3-dimensional (3D) transesophageal echocardiography (TEE) software and multidetector row computed tomography (MDCT) for aortic annulus sizing and investigated the influence of the quantity of aortic valve calcium (AVC) on the selection of TAVI prosthesis size. A total of 83 patients with severe aortic stenosis undergoing TAVI were evaluated. Maximal and minimal aortic annulus diameter, perimeter, and area were measured. AVC was assessed with computed tomography. The low and high AVC burden groups were defined according to the median AVC score. Overall, 3D TEE measurements slightly underestimated the aortic annulus dimensions as compared with MDCT (mean differences between maximum, minimum diameter, perimeter, and area: -1.7 mm, 0.5 mm, -2.7 mm, and -13 mm2, respectively). The agreement between 3D TEE and MDCT on aortic annulus dimensions was superior among patients with low AVC burden (<3,025 arbitrary units) compared with patients with high AVC burden (≥3,025 arbitrary units). The interobserver variability was excellent for both methods. 3D TEE and MDCT led to the same prosthesis size selection in 88%, 95%, and 81% of patients in the total population, the low, and the high AVC burden group, respectively. In conclusion, the novel automated 3D TEE imaging software allows accurate and highly reproducible measurements of the aortic annulus dimensions and shows excellent agreement with MDCT to determine the TAVI prosthesis size, particularly in patients with low AVC burden.

11. Transcathether implantation without preballoon dilation – How can echocardiography help

Abstract Type Clinical Research. Presentation Type Oral Presentation. Introduction Transcatheter aortic valve implantation (TAVI) is performed usually with preballoon dilation (PBD) which has its pros and cons. The aim of this study was to show the role of transesophageal echocardiographic (TEE) in selection of patients for TAVI without PBD and compare the results with those underwent PBD. Methodology 62 consecutive patients with severe symptomatic aortic stenosis underwent TEE evaluation before TAVI. 2D and 3D TEE imaging was used to assess aortic valve for suitability for direct valve implantation without PBD. Using echocardiographic criteria including sinotubular junction diameter, intersinus diameter, valve area, calcification, and degree of AR, echocardiographer agreed with the interventionist to consider patients either for TAVI with PBD or without PBD. We have 2 groups, group A underwent TAVI without PBD (n = 23) and group B underwent TAVI with PBD (n = 39). Results 62 patients (median age, 80.2 ± 11.7 years) with severe AS were evaluated. The mean aortic valve area was 0.74 ± 0.17 cm2. In group A, Edward valves were implanted in 21.7% (n = 5) and Core valves in 78.3% (n = 18). In group B, Edward valves were implanted in 46.2% (n = 18) and Core valves in 53.8% (n = 21). Post implantation balloon dilation to decrease or eliminate paravalvular leak was done in 21.7% (n = 5) in group A, vs 20.5% (n = 8) in group B, P = 0.9. In group A, residual paravalvular leak was seen in 13% vs 28.2% in group B, P = 0.2. Procedure-related mortality was not signii¬_cantly differ in both groups 4.3% (n = 1) vs 5.1% (n = 2), P = 0.89 and also longterm mortality at 29 ± 5 months, 17.4% (n = 4) vs 23.1% (n = 9) P = 0.59. Conclusion Pre TAVI TEE assessment of aortic valve can give a great help in selection of patients for TAVI without BPD which is feasible and safe. In our patients there was no difference in paravalvular leak or mortality in both groups.

Towards patient-specific modeling of mitral valve repair: 3D transesophageal echocardiography-derived parameter estimation.

Transesophageal echocardiography (TEE) is routinely used to provide important qualitative and quantitative information regarding mitral regurgitation. Contemporary planning of surgical mitral valve repair, however, still relies heavily upon subjective predictions based on experience and intuition. While patient-specific mitral valve modeling holds promise, its effectiveness is limited by assumptions that must be made about constitutive material properties. In this paper, we propose and develop a semi-automated framework that combines machine learning image analysis with geometrical and biomechanical models to build a patient-specific mitral valve representation that incorporates image-derived material properties. We use our computational framework, along with 3D TEE images of the open and closed mitral valve, to estimate values for chordae rest lengths and leaflet material properties. These parameters are initialized using generic values and optimized to match the visualized deformation of mitral valve geometry between the open and closed states. Optimization is achieved by minimizing the summed Euclidean distances between the estimated and image-derived closed mitral valve geometry. The spatially varying material parameters of the mitral leaflets are estimated using an extended Kalman filter to take advantage of the temporal information available from TEE. This semi-automated and patient-specific modeling framework was tested on 15 TEE image acquisitions from 14 patients. Simulated mitral valve closures yielded average errors (measured by point-to-point Euclidean distances) of 1.86 ± 1.24mm. The estimated material parameters suggest that the anterior leaflet is stiffer than the posterior leaflet and that these properties vary between individuals, consistent with experimental observations described in the literature.

Tricuspid annulus: A spatial and temporal analysis

Background:Traditional two-dimensional (2D) echocardiographic evaluation of tricuspid annulus (TA) dilation is based on single-frame measurements of the septolateral (S-L) dimension. This may not represent either the axis or the extent of dynamism through the entire cardiac cycle. In this study, we used real-time 3D transesophageal echocardiography (TEE) to analyze geometric changes in multiple axes of the TA throughout the cardiac cycle in patients without right ventricular abnormalities.Materials and Methods:R-wave-gated 3D TEE images of the TA were acquired in 39 patients undergoing cardiovascular surgery. The patients with abnormal right ventricular/tricuspid structure or function were excluded from the study. For each patient, eight points along the TA were traced in the 3D dataset and used to reconstruct the TA at four stages of the cardiac cycle (end- and mid-systole, end- and mid-diastole). Statistical analyses were applied to determine whether TA area, perimeter, axes, and planarity changed significantly over each stage of the cardiac cycle.Results:TA area (P = 0.012) and perimeter (P = 0.024) both changed significantly over the cardiac cycle. Of all the axes, only the posterolateral-anteroseptal demonstrated significant dynamism (P < 0.001). There was also a significant displacement in the vertical axis between the points and the regression plane in end-systole (P < 0.001), mid-diastole (P = 0.014), and mid-systole (P < 0.001).Conclusions:The TA demonstrates selective dynamism over the cardiac cycle, and its axis of maximal dynamism is different from the axis (S-L) that is routinely measured with 2D TEE.

Automated quantification of mitral valve anatomy using anatomical intelligence in three-dimensional echocardiography

BackgroundQuantitative analysis of mitral valve morphology with three-dimensional (3D) transesophageal echocardiography (TEE) provides anatomic information that can assist clinical decision-making. However, routine use of mitral valve quantification has been hindered by tedious workflow and high operator-dependence. The purpose of this paper was to evaluate the feasibility, accuracy and efficiency of a novel computer-learning algorithm using anatomical intelligence in ultrasound (AIUS) to automatically detect and quantitatively assess the mitral valve anatomy. MethodsA novice operator used AIUS to quantitatively assess mitral valve anatomy on the 3D TEE images of 55 patients (33 with mitral valve prolapse, 11 with functional mitral regurgitation, and 11 normal valves). The results were compared to that of manual mitral valve quantification by an experienced 3D echocardiographer and, in the 24 patients who underwent mitral valve repair, the surgical findings. Time consumption and reproducibility of AIUS were compared to the manual method. ResultsAIUS mitral valve quantification was feasible in 52 patients (95%). There were excellent agreements between AIUS and expert manual quantification for all mitral valve anatomic parameters (r=0.85–0.99, p<0.05). AIUS accurately classified surgically defined location of prolapse in 139 of 144 segments analyzed (97%). AIUS improved the intra- [intraclass-correlation coefficient (ICC)=0.91–0.99] and inter-observer (ICC=0.86–0.98) variability of novice users, surpassing the manual approach (intra-observer ICC=0.32–0.95; inter-observer ICC=0.45–0.93), yet requiring significantly less time (144±24s vs. 770±89s, p<0.0001). ConclusionAnatomic intelligence in 3D TEE image can provide accurate, reproducible, and rapid quantification of the mitral valve anatomy.

Visualization and Measurement of Mitral Valve Chordae Tendineae Using Three-Dimensional Transesophageal Echocardiography from the Transgastric Approach

The evaluation of the submitral apparatus is challenging from the conventional transesophageal approach. The aim of this study was to test the feasibility of using three-dimensional (3D) transesophageal echocardiographic (TEE) imaging from the transgastric approach to visualize the submitral apparatus and quantify the lengths of the chordae tendineae by using multiplanar reconstruction analysis. Twenty-two patients who had transgastric full-volume 3D TEE data sets before mitral valve surgery underwent surgical measurement of chordal length. A short-axis plane at the chordal level was extracted from the 3D data set to identify leaflet segments and the corresponding primary chords. Then, for each chord, the optimal plane was selected to visualize and measure the entire chordal length from its origin at the leaflet margin to the papillary muscle tips. Measurements were performed at the phase of the cardiac cycle when chordal length reached its maximum. Measured values were compared with surgical measurements using linear regression and Bland-Altman analyses. One hundred forty-six primary chords were measured intraoperatively. Three-dimensional TEE imaging was able to measure the lengths of all these chords. The surgical and 3D TEE measurements (mean, 1.96 ± 0.56 vs 1.93 ± 0.50 cm, respectively) correlated highly (r = 0.93, P < .0001), with a minimal bias of 0.03 cm and narrow limits of agreement from -0.39 to 0.45 cm. Transgastric 3D TEE imaging of the submitral apparatus allows visualization and accurate measurement of chordae tendineae lengths, which may be useful for planning mitral valve repair, including percutaneous transcatheter procedures.

Three-Dimensional Transesophageal Echocardiography in Degenerative Mitral Regurgitation

The morphology of mitral valve (MV) prolapse and flail may be extremely variable, with dominant and secondary dynamic lesions. Any pathologic valve appears unique and different from any other. Three-dimensional (3D) transesophageal echocardiography is a powerful tool to evaluate the geometry, dynamics, and function of the MV apparatus and may be of enormous value in helping surgeons perform valve repair procedures. Indeed, in contrast to the surgical view, 3D transesophageal echocardiography can visualize MV prolapse and flail in motion and from different perspectives. The purpose of this special article is not to provide a comprehensive review of degenerative MV disease but rather to illustrate different types of mitral prolapse and flail as they appear from multiple 3D transesophageal echocardiographic perspectives using a series of clinical scenarios. Because in everyday practice, 3D transesophageal echocardiographic images of MV prolapse and flail are usually observed in motion, each scenario is accompanied by several videos. Finally, the authors provide for each scenario a brief description of the surgical techniques that are usually performed at their institution.

Abstract 15817: Tricuspid Valve Imaging by 3D Transesophageal Echocardiography: Feasibility of Coaptation Length Measurement and Its Relationship With Severity of Regurgitation

Background: The coaptation length (CL) of the mitral valve leaflet decreases with increasing mitral regurgitation. Visualization of the CL of the tricuspid valve (TV) is challenging using conventional 2D echocardiography. The aims of this study were: (1) to test the feasibility of visualizing and quantifying the CL of the TV using three-dimensional (3D) transesophageal echocardiography (TEE), and (2) to study it relationship with the severity of tricuspid regurgitation (TR). Methods: Full-volume 3D TEE datasets of the TV were obtained in 24 patients from the transgastric approach. Using multiplanar reconstruction, short-axis plane depicting an en-face view of the TV was used to mark the central coaptation point (Fig. A). Three planes cutting through this point were then selected to view the 3 coaptation lines between: (1) anterior and posterior, (2) septal and anterior, and (3) septal and posterior TV leaflets (Figs. B-D). The CL was measured in each of these planes to obtain mean CL. The severity of tricuspid regurgitation was graded qualitatively as “none”, “trace”, “mild” and “moderate”. Results: Visualization of leaflet coaptation was feasible in 17/24 patients (71%). The mean CL was 0.89±0.03 cm in patients with no TR (N=4), 0.64±0.13 with trace TR (N=6), 0.50±0.07 with mild TR (N=3) and 0.13±0.11 with moderate TR (N=4). Since there was no overlap between the “moderate” group and the other 3 groups, the threshold of average CL for moderate TR was estimated to be between 0.25 (highest value in the “moderate” group) and 0.39 cm (lowest value in the other groups) (Fig. E). Conclusion: Visualization of the TV leaflet coaptation length from transgastric 3D TEE images is feasible in the majority of patients. TV coaptation length is inversely related to the severity of TR. The ability to visualize and quantify the CL of the TV may be useful when planning tricuspid valve repair surgery. Our findings suggest that CL below the threshold may indicate clinically significant TR.

Three-Dimensional Ultrasound-Derived Physical Mitral Valve Modeling

Advances in mitral valve repair and adoption have been partly attributed to improvements in echocardiographic imaging technology. To educate and guide repair surgery further, we have developed a methodology for fast production of physical models of the valve using novel three-dimensional (3D) echocardiographic imaging software in combination with stereolithographic printing. Quantitative virtual mitral valve shape models were developed from 3D transesophageal echocardiographic images using software based on semiautomated image segmentation and continuous medial representation algorithms. These quantitative virtual shape models were then used as input to a commercially available stereolithographic printer to generate a physical model of the each valve at end systole and end diastole. Physical models of normal and diseased valves (ischemic mitral regurgitation and myxomatous degeneration) were constructed. There was good correspondence between the virtual shape models and physical models. It was feasible to create a physical model of mitral valve geometry under normal, ischemic, and myxomatous valve conditions using 3D printing of 3D echocardiographic data. Printed valves have the potential to guide surgical therapy for mitral valve disease.

Semiautomated Detection and Quantification of Aortic Plaques from Three-Dimensional Transesophageal Echocardiography

Aortic atherosclerosis is a risk factor for cerebrovascular events. Two-dimensional transesophageal echocardiographic quantification of descending aortic plaques is time-consuming and underestimates plaque burden. The aim of this study was to assess the feasibility and accuracy of a novel semiautomated program that uses three-dimensional (3D) transesophageal echocardiography to identify and quantify aortic plaque severity as determined by plaque thickness, volume, and number. The relationship between maximum plaque thickness and volume was also examined. Descending aortic 3D transesophageal echocardiographic images from 58 patients were analyzed for plaque thickness, volume, and number using semiautomated custom software. The reference standard was manual assessment by an expert reader using 3D multiplanar reconstructions. Agreement and κ values were calculated to determine the program's accuracy against the reference standard. Correlation and bias were examined using linear regression and Bland-Altman statistics. Pearson's correlation was used to examine the relationship between maximum plaque thickness and volume. Analysis was possible in all patients. Overall agreement for the absolute presence or absence of plaque per patient was 95%. Agreement regarding the number of plaques per patient and plaque severity was high at 95% and 85%, respectively. Plaque volume was slightly underestimated by the program compared with manual measurements. The correlation between plaque thickness and volume was 0.56. The results of this study demonstrate that semiautomated plaque analysis of 3D transesophageal echocardiographic descending aortic data sets is feasible and accurate in determining plaque severity as measured by plaque thickness, volume, and number. This methodology allows the standardization of plaque quantification, which will improve its utility in clinical trials. A greater understanding of the importance of plaque thickness versus volume is needed.

Right Atrial Lipoma in a Patient With Complete Heart Block

A 70-year-old man with a recent history of high degree AV block presented to the hospital with progressive shortness of breath and dyspnea of exertion. A mobile intracardiac mass was found on transthoracic echocardiogram that was not present in his previous evaluations. Real time three-dimensional (3D) transesophageal echocardiography (TEE) images revealed a spherical mass within the right atrium; no enhancement after microbubble contrast infusion was noted. Modern echocardiography including 3D TEE and echocardiographic contrast perfusion imaging provide numerous advantages for non-invasive evaluation of intracardiac masses. J Med Cases. 2014;5(5):270-272 doi: http://dx.doi.org/10.14740/ jmc1746w

Intraoperative Three-Dimensional Versus Two-Dimensional Echocardiography for Left Ventricular Assessment

Three-dimensional (3D) transesophageal echocardiography (TEE) technology is now widely used intraoperatively in cardiac surgery. Left ventricular (LV) measurements with 3D transthoracic echocardiography correlate better with cardiac magnetic resonance measurements compared with traditional two-dimensional (2D) transthoracic echocardiography. In this study, we compared intraoperative 3D TEE against 2D TEE regarding quantitative indices of LV function. We performed 2D TEE and 3D TEE examinations on 156 patients scheduled for elective cardiac surgery. Two-dimensional TEE images of midesophageal 4-, 2-chamber, and long-axis views were acquired. LV volumes and ejection fraction (EF) were calculated by Simpson's method. Three-dimensional full-volume images were recorded to calculate by a semiautomated procedure LV volumes (indexed to body surface area) and EF. 3D and 2D LV dimensions and function, image quality, time for acquisition/analyses, and reproducibility were compared by the Wilcoxon matched-pairs signed-ranks test. Pairwise differences between 3D and 2D data were compared using 95% prediction intervals (PIs) and Bland-Altman methodology. 3D volumes were also plotted against 2D volumes in scatter plots using a 3-zone error grid. There was no significant difference between 3D and 2D in the estimation of EF (P = 0.227; median pairwise difference, -0.4% [95% PIs, -8.6% to 8.8%]). 3D LV indexed end-diastolic volumes (iEDVs) and end-systolic volumes (iESVs) were larger than 2D iEDVs (P < 0.001; median pairwise difference, 3.3 mL/m [95% PIs, -9.4 to 14.1 mL/m] and iESV: P < 0.001; median pairwise difference, 1.4 mL/m [95% PIs, -5.2 to 10.1 mL/m]). In the vast majority of cases (98.8% of cases for iEDV and 92.8% of cases for iESV), the difference between 2D and 3D TEE indexed volumes did not alter classification into normal, mildly to moderately dilated, or severely dilated volumes, as demonstrated by the 3-zone error grid analysis. Acquisition of 3D TEE image and analysis were not feasible in 4 patients (2.5%) for whom a quantitative 2D assessment of the LV was also impossible. 3D and 2D quality image was similar (P = 0.206). There was no difference in 3D versus 2D acquisition time (P = 0.805; pairwise difference = 2 seconds [95% PIs, -20 to 35 seconds]), but 3D analysis required more time (P < 0.001; pairwise difference = 117 seconds [95% PIs, 66 to 197 seconds]). Differences in repeated 3D versus 2D indexed volumes were not statistically significant, both considering interobserver reproducibility (iEDV: P = 0.125; pairwise difference, 0.26 ± 1.76 mL [95% PIs, -3.58 to 3.73 mL] and iESV: P = 0.126; pairwise difference, -0.16 ± 1.67 mL [95% PIs, -3.96 to 3.69 mL]) and intraobserver reproducibility (iEDV: P = 0.975; pairwise difference, -0.02 ± 1.20 mL [95% PIs, -2.32 to 2.08 mL] and iESV: P = 0.228; pairwise difference, -0.19 ± 1.13 mL [95% PIs, -2.47 to 2.53 mL]). Intraoperative 3D TEE quantification of LV global function, image acquisition time, and reproducibility was not statistically different when compared with 2D TEE. It was however associated with calculation of larger LV volumes and a longer analysis time. Nevertheless, the 3-zone error grid analysis of the LV indexed volumes showed that the difference between 3D and 2D measurements does not affect the LV classification as normal, mildly to moderately dilated, or severely dilated.