A left ventricular phantom for 3D echocardiographic twist measurements.

Traditional two-dimensional (2D) ultrasound speckle tracking echocardiography (STE) studies have shown a wide range of twist values, also for normal hearts, which is due to the limitations of short-axis 2D ultrasound. The same limitations do not apply to three-dimensional (3D) ultrasound, and several studies have shown 3D ultrasound to be superior to 2D ultrasound, which is unreliable for measuring twist. The aim of this study was to develop a left ventricular twisting phantom and to evaluate the accuracy of 3D STE twist measurements using different acquisition methods and volume rates (VR). This phantom was not intended to simulate a heart, but to function as a medium for ultrasound deformation measurement. The phantom was made of polyvinyl alcohol (PVA) and casted using 3D printed molds. Twist was obtained by making the phantom consist of two PVA layers with different elastic properties in a spiral pattern. This gave increased apical rotation with increased stroke volume in a mock circulation. To test the accuracy of 3D STE twist, both single-beat, as well as two, four and six multi-beat acquisitions, were recorded and compared against twist from implanted sonomicrometry crystals. A custom-made software was developed to calculate twist from sonomicrometry. The phantom gave sonomicrometer twist values from 2.0° to 13.8° depending on the stroke volume. STE software tracked the phantom wall well at several combinations of temporal and spatial resolution. Agreement between the two twist methods was best for multi-beat acquisitions in the range of 14.4-30.4 volumes per second (VPS), while poorer for single-beat and higher multi-beat VRs. Smallest offset was obtained at six-beat multi-beat at 17.1 VPS and 30.4 VPS. The phantom proved to be a useful tool for simulating cardiac twist and gave different twist at different stroke volumes. Best agreement with the sonomicrometer reference method was obtained at good spatial resolution (high beam density) and a relatively low VR. 3D STE twist values showed better agreement with sonomicrometry for most multi-beat recordings compared with single-beat recordings.

Mitral valve navigator. A new diagnostic tool for effective regurgitant orifice quantification in mitral regurgitation.

INTRODUCTION: Mitral regurgitation severity assessment is usually carried out using qualitative, semiquantitative, and quantitative parameters. The mitral valve navigation (MVN) tool allows to measure the mitral effective regurgitant orifice (MERO) from 3D echo datasets. Our aim was to validate the MVN as a new tool to quantify MERO. A secondary aim was to assess the intra- and interobserver variability. METHODS: This is a retrospective study in which consecutive subjects undergoing a transoesophageal echocardiogram for more than mild mitral regurgitation evaluation were included. MERO measurement obtained by means of 3D color Doppler was used as the gold standard method for comparison. In every patient, MERO was also obtained using the MVN tool. RESULTS: Fifty-nine consecutive patients were analyzed (47.5% female; mean age 50.8 years). Mitral regurgitation was moderate in 23 (39%) and severe in 36 (61%) patients. Forty patients (67.8%) had a primary and 19 (32.2%) a secondary mitral regurgitation. The intraclass correlation coefficient (ICC) between 3D color Doppler and MVN was excellent (ICC: 0.95; 95% CI: 0.82 to 0.98; P < 0.001) in the total group and for patients with primary and secondary mitral regurgitation. Intra- and interobserver agreements were also good. CONCLUSIONS: Mitral valve navigator shows an excellent accuracy for measuring MERO when the transoesophageal 3D color Doppler is used as the reference method, either primary or secondary mitral regurgitation. Intraobserver reproducibility and interobserver reproducibility are also excellent. These findings make this software a good alternative method to measure mitral regurgitation severity.

Acoustic characterization of a miniature matrix transducer for pediatric 3D transesophageal echocardiography.

This paper presents the design, fabrication and characterization of a miniature PZT-on-CMOS matrix transducer for real-time pediatric 3-dimensional (3D) transesophageal echocardiography (TEE). This 3D TEE probe consists of a 32 × 32 array of PZT elements integrated on top of an Application Specific Integrated Circuit (ASIC). We propose a partitioned transmit/receive array architecture wherein the 8 × 8 transmitter elements, located at the centre of the array, are directly wired out and the remaining receive elements are grouped into 96 sub-arrays of 3 × 3 elements. The echoes received by these sub-groups are locally processed by micro-beamformer circuits in the ASIC that allow pre-steering up to ±37°. The PZT-on-CMOS matrix transducer has been characterized acoustically and has a centre frequency of 5.8 MHz, -6 dB bandwidth of 67%, a transmit efficiency of 6 kPa/V at 30 mm, and a receive dynamic range of 85 dB with minimum and maximum detectable pressures of 5 Pa and 84 kPa respectively. The properties are very suitable for a miniature pediatric real-time 3D TEE probe.

Fast Volumetric Imaging Using a Matrix Transesophageal Echocardiography Probe with Partitioned Transmit-Receive Array.

We describe a 3-D multiline parallel beamforming scheme for real-time volumetric ultrasound imaging using a prototype matrix transesophageal echocardiography probe with diagonally diced elements and separated transmit and receive arrays. The elements in the smaller rectangular transmit array are directly wired to the ultrasound system. The elements of the larger square receive aperture are grouped in 4 × 4-element sub-arrays by micro-beamforming in an application-specific integrated circuit. We propose a beamforming sequence with 85 transmit-receive events that exhibits good performance for a volume sector of 60°â€¯× 60°. The beamforming is validated using Field II simulations, phantom measurements and in vivo imaging. The proposed parallel beamforming achieves volume rates up to 59 Hz and produces good-quality images by angle-weighted combination of overlapping sub-volumes. Point spread function, contrast ratio and contrast-to-noise ratio in the phantom experiment closely match those of the simulation. In vivo 3-D imaging at 22-Hz volume rate in a healthy adult pig clearly visualized the cardiac structures, including valve motion.

Usefulness of echocardiographic-fluoroscopic fusion imaging in children with congenital heart disease.

BACKGROUND: Transoesophageal echocardiography (TOE) has become indispensable in the catheterization laboratory in the guidance of some percutaneous interventions, as a complementary imaging technique to fluoroscopy. However, the two imaging modalities are presented separately and differently, making interpretation of the anatomical spatial relationships complicated. EchoNavigator® (Philips Healthcare, Best, the Netherlands) is an innovative software package, enabling fusion of fluoroscopic and echocardiographic images on the same screen. AIMS: To assess the feasibility of EchoNavigator® in the guidance of interventional procedures, and to present our initial clinical experience with this software. METHODS: Children with congenital heart disease who underwent interventional catheterization needing guidance with TOE from December 2015 to December 2017 were included. TOE was realized using a X7-2t TOE probe (Philips Healthcare) connected to an echocardiographic system (EPIC™; Philips Healthcare, Andover, MA). Fluoroscopy was realized using the Allura Xper FD/10 system (Philips Healthcare). Image fusion was attempted in all patients using EchoNavigator®. Markers were positioned on the target zone on echocardiographic images, and projected onto the merged screen. RESULTS: Fifty-one children were included (mean age, 8 years; mean weight, 25kg). Thirty-six patients underwent atrial septal defect closure, 10 ventricular septal defect closure, three aortic valve dilatation and two right ventricular outflow tract revalvulation. Image fusion was successfully obtained in all patients during all steps of the procedure. No complication related to the TOE probe was observed. Markers were successfully positioned in the all target zones, and were automatically projected onto the fusion screen. CONCLUSIONS: The EchoNavigator® system is feasible and safe in the guidance of interventional catheterization in children with congenital heart disease; it enables better appreciation of anatomical relationships and improves the confidence of the interventionist.

Assessment of left ventricular size and function by 3-dimensional transthoracic echocardiography: Impact of the echocardiography platform and analysis software.

BACKGROUND: Whether echocardiography platform and analysis software impact left ventricular (LV) volumes, ejection fraction (EF), and stroke volume (SV) by transthoracic tridimensional echocardiography (3DE) has not yet been assessed. Hence, our aim was to compare 3DE LV end-diastolic and end-systolic volumes (EDV and ESV), LVEF, and SV obtained with echocardiography platform from 2 different manufacturers. METHODS: 3DE was performed in 84 patients (65% of screened consecutive patients), with equipment from 2 different manufacturers, with subsequent off-line postprocessing to obtain parameters of LV function and size (Philips QLAB 3DQ and General Electric EchoPAC 4D autoLVQ). Twenty-five patients with clinical indication for cardiac magnetic resonance imaging served as a validation subgroup. RESULTS: LVEDV and LVESV from 2 vendors were highly correlated (r = 0.93), but compared with 4D autoLVQ, the use of Qlab 3DQ resulted in lower LVEDV and LVESV (bias: 11 mL, limits of agreement: -25 to +47 and bias: 6 mL, limits of agreement: -22 to +34, respectively). The agreement between LVEF values of each software was poor (intraclass correlation coefficient 0.62) despite no or minimal bias. SVs were also lower with Qlab 3DQ advanced compared with 4D autoLVQ, and both were poorly correlated (r = 0.66). Consistently, the underestimation of LVEDV, LVESV, and SV by 3DE compared with cardiac magnetic resonance imaging was more pronounced with Philips QLAB 3DQ advanced than with 4D autoLVQ. CONCLUSIONS: The echocardiography platform and analysis software significantly affect the values of LV parameters obtained by 3DE. Intervendor standardization and improvements in 3DE modalities are needed to broaden the use of LV parameters obtained by 3DE in clinical practice.

Dynamic Patient-Specific Three-Dimensional Simulation of Mitral Repair: Can We Practice Mitral Repair Preoperatively?

OBJECTIVE: Planned mitral repair strategies are generally established from preoperative echocardiography; however, specific details of the repair are often determined intraoperatively. We propose that three-dimensional printed, patient-specific, dynamic mitral valve models may help surgeons plan and trial all the details of a specific patient's mitral repair preoperatively. METHODS: Using preoperative echocardiography, segmentation, modeling software, and three-dimensional printing, we created dynamic, high-fidelity, patient-specific mitral valve models including the subvalvular apparatus. We assessed the accuracy of 10 patient mitral valve models anatomically and functionally in a heart phantom simulator, both objectively by blinded echocardiographic assessment, and subjectively by two mitral repair experts. After this, we attempted model mitral repair and compared the outcomes with postoperative echocardiography. RESULTS: Model measurements were accurate when compared with patients on anterior-posterior diameter, circumference, and anterior leaflet length; however, less accurate on posterior leaflet length. On subjective assessment, Likert scores were high at 3.8 ± 0.4 and 3.4 ± 0.7, suggesting good fidelity of the dynamic model echocardiogram and functional model in the phantom to the preoperative three-dimensional echocardiogram, respectively. Mitral repair was successful in all 10 models with significant reduction in mitral insufficiency. In two models, mitral repair was performed twice, using two different surgical techniques to assess which provided a better outcome. When compared with the actual patient mitral repair outcome, the repaired models compared favorably. CONCLUSIONS: Complex mitral valve modeling seems to predict an individual patient's mitral anatomy well, before surgery. Further investigation is required to determine whether deliberate preoperative practice can improve mitral repair outcomes.

Feasibility of Multiplane-Transmit Beamforming for Real-Time Volumetric Cardiac Imaging: A Simulation Study.

Today's 3-D cardiac ultrasound imaging systems suffer from relatively low spatial and temporal resolution, limiting their applicability in daily clinical practice. To address this problem, 3-D diverging wave imaging with spatial coherent compounding (DWC) as well as 3-D multiline-transmit (MLT) imaging have recently been proposed. Currently, the former improves the temporal resolution significantly at the expense of image quality and the risk of introducing motion artifacts, whereas the latter only provides a moderate gain in volume rate but mostly preserves quality. In this paper, a new technique for real-time volumetric cardiac imaging is proposed by combining the strengths of both approaches. Hereto, multiple planar (i.e., 2-D) diverging waves are simultaneously transmitted in order to scan the 3-D volume, i.e., multiplane transmit (MPT) beamforming. The performance of a 3MPT imaging system was contrasted to that of a 3-D DWC system and that of a 3-D MLT system by computer simulations during both static and moving conditions of the target structures while operating at similar volume rate. It was demonstrated that for stationary targets, the 3MPT imaging system was competitive with both the 3-D DWC and 3-D MLT systems in terms of spatial resolution and sidelobe levels (i.e., image quality). However, for moving targets, the image quality quickly deteriorated for the 3-D DWC systems while it remained stable for the 3MPT system while operating at twice the volume rate of the 3-D-MLT system. The proposed MPT beamforming approach was thus demonstrated to be feasible and competitive to state-of-the-art methodologies.

4-D ICE: A 2-D Array Transducer With Integrated ASIC in a 10-Fr Catheter for Real-Time 3-D Intracardiac Echocardiography.

We developed a 2.5 ×6.6 mm 2 2 -D array transducer with integrated transmit/receive application-specific integrated circuit (ASIC) for real-time 3-D intracardiac echocardiography (4-D ICE) applications. The ASIC and transducer design were optimized so that the high-voltage transmit, low-voltage time-gain control and preamp, subaperture beamformer, and digital control circuits for each transducer element all fit within the 0.019-mm 2 area of the element. The transducer assembly was deployed in a 10-Fr (3.3-mm diameter) catheter, integrated with a GE Vivid E9 ultrasound imaging system, and evaluated in three preclinical studies. The 2-D image quality and imaging modes were comparable to commercial 2-D ICE catheters. The 4-D field of view was at least 90 ° ×60 ° ×8 cm and could be imaged at 30 vol/s, sufficient to visualize cardiac anatomy and other diagnostic and therapy catheters. 4-D ICE should significantly reduce X-ray fluoroscopy use and dose during electrophysiology ablation procedures. 4-D ICE may be able to replace transesophageal echocardiography (TEE), and the associated risks and costs of general anesthesia, for guidance of some structural heart procedures.

Prolonged transesophageal echocardiography during percutaneous closure of the left atrial appendage without general anesthesia: the utility of the Janus mask.

PURPOSE: Left atrial appendage (LAA) closure is an interventional procedure increasingly used to prevent stroke in patients with permanent atrial fibrillation and contraindications to anticoagulation therapy. As this procedure requires a relatively immobile patient and performance of continuous and prolonged transesophageal echocardiography (TEE), it is usually performed under general anesthesia. In this case series, we describe the feasibility of prolonged TEE for percutaneous LAA closure using a new noninvasive ventilation device that can avoid the need for endotracheal intubation and general anesthesia. CLINICAL FEATURES: Percutaneous LAA closure was performed under deep sedation in three elderly patients with permanent atrial fibrillation. Sedation was obtained with a combination of midazolam, propofol, and remifentanil. Continuous intraoperative TEE was performed through the port of the newly available Janus mask (Biomedical Srl; Florence, Italy), allowing for noninvasive ventilation (pressure support = 12-16 cm H2O; positive end-expiratory pressure = 7 cm H2O; FIO2 = 0.3) in these spontaneously breathing patients. The total procedure times ranged from 75-90 min. The patients reported excellent satisfaction with the sedation received in terms of discomfort experienced during the procedure, capacity to recall the procedure, and comfort with the mask. The operators also rated the procedural conditions as excellent. CONCLUSION: Deep sedation with noninvasive ventilation may be a reasonable and safe alternative to general endotracheal anesthesia in patients requiring prolonged TEE for noninvasive cardiac procedures, including LAA closure.

Acute effect of MitraClip implantation on mitral valve geometry in patients with functional mitral regurgitation: insights from three-dimensional transoesophageal echocardiography.

AIMS: Our aim was to evaluate the acute effects of transcatheter edge-to-edge mitral valve repair using the MitraClip device on mitral valve geometry in patients with functional mitral regurgitation (FMR). METHODS AND RESULTS: Forty-two patients (age 73 years [IQ range 66.1-78.0], 55% men, 62% ischaemic FMR) with moderate-to-severe and severe FMR treated with the MitraClip were included. Three-dimensional transoesophageal echocardiography was performed prior to and immediately after MitraClip implantation. Acute changes of mitral annular and leaflet geometry were assessed with dedicated mitral modelling software. FMR less than moderate grade was achieved in 36 (86%) patients. After MitraClip implantation, the mitral annulus became more elliptical (ellipticity from 122±17% to 129±18%; p=0.04) with a non-significant reduction in anteroposterior diameter (33±6 to 32±5 mm, p=0.08). The coaptation area increased from 350 mm2 (IQ range 289-493 mm2) to 434 mm2 (IQ range 328-523 mm2, p=0.008). In particular, a larger part of the anterior mitral leaflet was included in the coaptation, leaving a smaller exposed anterior leaflet length of the A2 segment (from 27±6 mm to 25±5 mm, p<0.05) while the exposed length of the posterior leaflet (P2 level) remained unchanged (12±4 mm pre- vs. 13±4 mm post-repair, p=0.15). There was no change in total leaflet area (1,811±582 mm2 pre- vs. 1,870±506 mm2 post-repair, p=0.18). Annular height to intercommissural width ratio and tenting volume remained unchanged, suggesting no increase in leaflet stress. CONCLUSIONS: The MitraClip device affects MV geometry in FMR patients by increasing mitral annular ellipticity and coaptation area.

Accuracy and reproducibility of novel echocardiographic three-dimensional automated software for the assessment of the aortic root in candidates for thanscatheter aortic valve replacement.

AIMS: A specialized three-dimensional transoesophageal echocardiography (3D-TOE) reconstruction tool has recently been introduced; the system automatically configures a geometric model of the aortic root from the images obtained by 3D-TOE and performs quantitative analysis of these structures. The aim of this study was to compare the measurements of the aortic annulus (AA) obtained by the new model to that obtained by 3D-TOE and multidetector computed tomography (MDCT) in candidates to transcatheter aortic valve implantation (TAVI) and to assess the reproducibility of this new method. METHODS AND RESULTS: We included 31 patients who underwent TAVI. The AA diameters and area were evaluated by the manual 3D-TOE method and by the automatic software. We showed an excellent correlation between the measurements obtained by both methods: intra-class correlation coefficient (ICC): 0.731 (0.508-0.862), r: 0.742 for AA diameter and ICC: 0.723 (0.662-0.923), r: 0.723 for the AA area, with no significant differences regardless of the method used. The interobserver variability was superior for the automatic measurements than for the manual ones. In a subgroup of 10 patients, we also found an excellent correlation between the automatic measurements and those obtained by MDCT, ICC: 0.941 (0.761-0.985), r: 0.901 for AA diameter and ICC: 0.853 (0.409-0.964), r: 0.744 for the AA area. CONCLUSION: The new automatic 3D-TOE software allows modelling and quantifying the aortic root from 3D-TOE data with high reproducibility. There is good correlation between the automated measurements and other 3D validated techniques. Our results support its use in clinical practice as an alternative to MDCT previous to TAVI.

A Prototype PZT Matrix Transducer With Low-Power Integrated Receive ASIC for 3-D Transesophageal Echocardiography.

This paper presents the design, fabrication, and experimental evaluation of a prototype lead zirconium titanate (PZT) matrix transducer with an integrated receive ASIC, as a proof of concept for a miniature three-dimensional (3-D) transesophageal echocardiography (TEE) probe. It consists of an array of 9 ×12 piezoelectric elements mounted on the ASIC via an integration scheme that involves direct electrical connections between a bond-pad array on the ASIC and the transducer elements. The ASIC addresses the critical challenge of reducing cable count, and includes front-end amplifiers with adjustable gains and micro-beamformer circuits that locally process and combine echo signals received by the elements of each 3 ×3 subarray. Thus, an order-of-magnitude reduction in the number of receive channels is achieved. Dedicated circuit techniques are employed to meet the strict space and power constraints of TEE probes. The ASIC has been fabricated in a standard 0.18-µm CMOS process and consumes only 0.44 mW/channel. The prototype has been acoustically characterized in a water tank. The ASIC allows the array to be presteered across ±37° while achieving an overall dynamic range of 77 dB. Both the measured characteristics of the individual transducer elements and the performance of the ASIC are in good agreement with expectations, demonstrating the effectiveness of the proposed techniques.

Tomosíntesis digital en el cáncer de mama. Revisión sistemática / Digital tomosynthesis in breast cancer: a systematic review

Objetivo. Estimar y comparar la validez diagnóstica de la tomosíntesis y la mamografía digital para cribar y diagnosticar el cáncer de mama. Material y métodos. Realizamos una revisión sistemática consultando MedLine, EMBASE y Web of Science en el periodo de junio de 2010 a febrero de 2013. Los términos de búsqueda fueron: cáncer de mama, cribado, tomosíntesis, mamografía, sensibilidad y especificidad. Se incluyeron estudios de pruebas diagnósticas y revisiones sistemáticas. Dos investigadores hicieron la selección y evaluación. Usamos QUADAS 2 para valorar el riesgo de sesgo y los criterios NICE para el nivel de evidencia. Se hizo una síntesis narrativa. Resultados. De los 151 estudios originales identificados se seleccionaron 11 que incluyeron 2.475 mujeres. Su calidad fue baja, con riesgo de sesgo de selección y seguimiento, y limitaciones para aplicar sus resultados. Su nivel de evidencia no fue superior a II. La sensibilidad de la tomosíntesis osciló entre el 69 y el 100% y la especificidad entre el 54 y el 100%. El cociente de probabilidad negativo fue bueno, lo que la convertiría en una prueba de confirmación diagnóstica. La tomosíntesis con una proyección no fue superior a la mamografía digital con 2, y con 2 proyecciones los resultados no fueron concluyentes. Conclusiones. Los resultados de la validez diagnóstica de la tomosíntesis en el diagnóstico del cáncer de mama no fueron concluyentes, y no los hubo para usarla en el cribado (AU)

Objective. To estimate and compare the diagnostic validity of tomosynthesis and digital mammography for screening and diagnosing breast cancer. Material and methods. We systematically searched MedLine, EMBASE, and Web of Science for the terms breast cancer, screening, tomosynthesis, mammography, sensitivity, and specificity in publications in the period comprising June 2010 through February 2013. We included studies on diagnostic tests and systematic reviews. Two reviewers selected and evaluated the articles. We used QUADAS 2 to evaluate the risk of bias and the NICE criteria to determine the level of evidence. We compiled a narrative synthesis. Results. Of the 151 original studies identified, we selected 11 that included a total of 2475 women. The overall quality was low, with a risk of bias and follow-up and limitations regarding the applicability of the results. The level of evidence was not greater than level II. The sensitivity of tomosynthesis ranged from 69% to 100% and the specificity ranged from 54% to 100%. The negative likelihood ratio was good, and this makes tomosynthesis useful as a test to confirm a diagnosis. One-view tomosynthesis was no better than two-view digital mammography, and the evidence for the superiority of two-view tomosynthesis was inconclusive. Conclusions. The results for the diagnostic validity of tomosynthesis in the diagnosis of breast cancer were inconclusive and there were no results for its use in screening (AU)

Mitral valve analysis adding a virtual semi-transparent annulus plane for detection of prolapsing segments.

BACKGROUND: We hypothesized that a novel three-dimensional virtual semi-transparent annulus plane (3D VSAP) presented on a holographic screen can be used to visualize the prolapsing tissue in degenerative mitral valve disease and furthermore, provide us with geometrical data of the mitral valve apparatus. Phantom and patient studies were designed to demonstrate the feasibility of creating a semi-automatic, semi-transparent mitral annulus plane visualized on a holographic display. METHODS: Ten pipe cleaners mimicking the mitral annulus with different shapes and three types of annuloplasty rings served as phantoms. We obtained 3D transoesophageal examination of the phantoms in a special designed box filled with water. Recordings were converted to the holographic display and a 3D VSAP was created. The ratio of the major and minor axes as well as the non-planar angles were calculated and compared with direct measures of the phantoms. Forty patients with degenerative mitral valve disease were then analyzed with 3D transthoracic echocardiography (TTE) and a 3D VSAP was created on the holographic display. A total of 240 segments were analyzed by two independent observers, one echo expert (observer I), and the other novice with limited echo experience (observer II). The two observers created the 3D VSAP in each patient before suggesting the valve pathology. RESULTS: The major/minor axes ratio and non-planar angles by 3D VSAP correlated with direct measurements by r = 0.65, p < 0.02 and r = 0.99, p < 0.0001, respectively. The sensitivity and specificity of the 3D VSAP method in patients was 81 and 97%, respectively (observer I) and for observer II 77 and 96%, respectively. The accuracy and precisions were 93.9 and 89.4%, respectively (observer I), 92.3 and 85.1% (observer II). Mitral valve analysis adding a 3D VSAP was feasible with high accuracy and precision, providing a quick and less subjective method for diagnosing mitral valve prolapse. This novel method may improve preoperative diagnostics and may relieve a better understanding of the pathophysiology of mitral valve disease. Thus, based on the specific findings in each patient, a tailored surgical repair can be planned and hopefully enhance long-term repair patency in the future.

Quantification of Left Ventricular Linear, Areal and Volumetric Dimensions: A Phantom and in Vivo Comparison of 2-D and Real-Time 3-D Echocardiography with Cardiovascular Magnetic Resonance.

Two-dimensional echocardiography and real-time 3-D echocardiography have been reported to underestimate human left ventricular volumes significantly compared with cardiovascular magnetic resonance. We investigated the ability of 2-D echocardiography, real-time 3-D echocardiography and cardiovascular magnetic resonance to delineate dimensions of increasing complexity (diameter-area-volume) in a multimodality phantom model and in vivo, with the aim of elucidating the main cause of underestimation. All modalities were able to delineate phantom dimensions with high precision. In vivo, 2-D and real-time 3-D echocardiography underestimated short-axis end-diastolic linear and areal and all left ventricular volumetric dimensions significantly compared with cardiovascular magnetic resonance, but not short-axis end-systolic linear and areal dimensions. Underestimation increased successively from linear to volumetric left ventricular dimensions. When analyzed according to the same principles, 2-D and real-time 3-DE echocardiography provided similar left ventricular volumes. In conclusion, echocardiographic underestimation of left ventricular dimensions is due mainly to inherent technical differences in the ability to differentiate trabeculated from compact myocardium. Identical endocardial border definition criteria are needed to minimize differences between the modalities and to ensure better comparability in clinical practice.

Application of three-dimensional speckle tracking echocardiography to assess left ventricular regional work using wall tension-regional area loop.

Three-dimensional (3-D) speckle tracking echocardiography allows us to track a change in regional endocardial surface area. The change of regional area during a cardiac cycle should be useful for assessing left ventricular regional work. We investigated the feasibility of assessing regional work, calculated as the area within the wall tension-regional area (T-A) loop using 3-D echocardiography. Three-dimensional full-volume images were acquired using 3-D echocardiography (Artida, Toshiba) at baseline and during brief occlusion of the left circumflex coronary artery in eight dogs. Wall tension was calculated according to Laplace's law for a spherical model. Area change ratio (in %) determined by area tracking was transformed into a change of regional area (in cm(2)) by a custom software. We calculated the area within the T-A loop (TAA) in the area under transient ischemia (risk area) and the remote area as regional work and validated the T-A loop method by comparing the global integral of TAA with the total work assessed by the pressure-volume loop. During coronary occlusion, regional work for the risk area significantly decreased (baseline vs. occlusion, 26.8 ± 10.7 vs. 18.4 ± 7.8 mmHg·cm(3); P < 0.05), whereas that for the remote area did not change. The global integral of TAA closely correlated with the total work assessed by the pressure-volume loop (r = 0.91, P < 0.0001). The wall T-A loop reflected regional dysfunction caused by myocardial ischemia. This analysis using 3-D speckle tracking echocardiography might be useful to quantify left ventricular regional work.

Evaluation of right ventricular function using single-beat three-dimensional echocardiography in neonate.

Aim of our study was to evaluate right ventricular (RV) systolic function in neonate using newly developed single-beat three-dimensional echocardiography (sb3DE). We enrolled 15 healthy or premature neonates (0-53 days after birth). We scanned one beat full volume using Siemens ACUSON SC2000 (Siemens AG) echocardiography with 4Z1c full-volume transducer without ECG gating. RV end-diastolic volume (RVEDV) and RV end-systolic volume (RVESV) were computed with special software dedicated to analysis for RV volume. RV ejection fraction (RVEF) and RV stroke volume (3D-RVSV) were calculated. And RV stroke volume was also determined from the recordings of ejection blood flow velocity and diameter at the level of the pulmonary orifice in RV outflow tract (Doppler-RVSV). Tricuspid annular plane systolic excursion (TAPSE) was also measured by 2D echocardiography. RVEDV ranged from 5.1 to 10.7 ml (average 7.5 ml), RVESV ranged from 2.3 to 5.8 ml (average 3.9 ml). There was a good correlation between 3D-RVSV and Doppler-RVSV (r = 0.77). Bland-Altman plot revealed that 3D-RVSV became underestimation of an average of 1.78 ml compared to Doppler-RVSV. And TAPSE positively correlated with 3D-RVEF (r = 0.58, P = 0.038). Newly developed sb3DE enables us to perform three-dimensional acquisition of RV volume without ECG gating even in neonate. However, 3D-RVSV currently tends to be underestimated in neonatal measurement.

[Application fields of intraoperative transesophageal 3D echocardiography]. / Anwendungsgebiete der intraoperativen transösophagealen 3D-Echokardiographie.

Intraoperative transesophageal echocardiography (TEE) is an established diagnostic tool and has to be regarded as the standard of care for intraoperative monitoring and cardiac surgical decision-making. Furthermore, intraoperative TEE is also used for monitoring and assessment of hemodynamic changes and the detection of previously unknown pathologies. In the past few years 3D-TEE has extended the spectrum of 2D-TEE by allowing pathomorphological features to be more easily and intuitively linked to the anatomy of the heart and the great vessels. Thus, a comprehensive 2D-TEE examination is favorably complemented by focused 3D-TEE. Especially during mitral valve surgery, 3D-TEE has proven its superiority in the diagnosis of the underlying pathology as demonstrated by a large number of studies in this field. This review presents the available data about the role of intraoperative 3D-TEE echocardiography and introduces practical fields of application.