Quantification Of Ventricular Volumes Research Articles

Multimodality Noninvasive Imaging for Assessment of Congenital Heart Disease

Major advances in the field of pediatric cardiology and cardiac surgery over the last several decades have led to a dramatic improvement in survival rates for most forms of congenital heart disease (CHD). For example, hypoplastic left heart syndrome, a previously lethal defect, now has early survival rates up to 90% at major centers.1 These improved outcomes have produced a growing population of survivors with complex CHD who are now reaching adulthood (Figure 1). During this period, improvements in surgical and medical treatments have been accompanied by developments in diagnostic modalities. Echocardiography has replaced catheterization as the primary diagnostic modality, and it is now uncommon for newborn infants to undergo catheterization for purely diagnostic purposes. Although echocardiography remains the bedrock of noninvasive cardiac imaging, the array of diagnostic modalities and techniques available continue to grow and this has spawned the specialty of “noninvasive cardiac imaging” and the need for the “cardiac imager” to be adept in all the different modalities. Figure 1. Percentage of patients under the age of 1 year (grey bars) and over the age of 18 years (black bars) undergoing echocardiography at Children’s Hospital Boston from 1983 through 2006. Note the reverse trends of these age groups reflecting the steady increase in the proportion of adult patients with congenital heart disease. Although the absolute number of infants undergoing echocardiography during this time period has increased, their proportion has steadily declined. Echocardiography, cardiac magnetic resonance (CMR), and cardiac computed tomography (CCT) are the primary modalities used for noninvasive cardiac imaging in patients with CHD. Nuclear scintigraphy is used in selected circumstances. The Table summarizes the strengths and weaknesses of each modality. Figure 2 shows temporal trends in utilization for the various noninvasive cardiac imaging techniques at our center. It is clear that echocardiography is the most frequently …

Walking with Gianluca Di Bella during the development of clinical cardiac imaging

Cardiac magnetic resonance imaging (MRI) for the diagnosis and management of many cardiac diseases has been established in clinical practice. It provides anatomic and functional information and is the most precise technique for quantification of ventricular volume, function and mass. Among cardiac MRI sequences used in clinical practice, delayed contrast enhancement is an accurate and reliable method used in the diagnosis of ischemic and nonischemic cardiomyopathies. In addition, new technology applied in echocardiographic imaging has permitted quantification of myocardial deformations with 2-dimensional strain imaging (longitudinal, circumferential and radial strain). Cardiac MRI and echocardiography therefore both play a crucial role in the diagnosis and management of cardiovascular disease. Dr. Di Bella and colleagues have defined the roles of cardiac MRI and echocardiography in many clinical and experimental settings.

Left ventricular volumetry in healthy children and adolescents: comparison of two different real-time three-dimensional matrix transducers with cardiovascular magnetic resonance

To assess the accuracy of different hardware and software settings for left ventricular (LV) volume quantification in children using real-time three-dimensional echocardiography (RT3DE). The impact of different matrix transducers (IE 33, X3-1 and VIVID 7, V3) and quantification software settings [TOMTEC; contour-finding activity (tCFA) values ranging from 30 to 70 U] on the accuracy of LV indices was tested in 24 healthy children/adolescents (median = 12.6 years) and 25 paediatric patients with Tetralogy-of-Fallot (TOF) (median = 7.3 years) with abnormally shaped ventricles. RT3DE was compared with cardiovascular magnetic resonance (CMR) volumetry as reference. Best agreement (Bland-Altman analysis) was achieved using a tCFA value of 30 U. Applying the V3 device, end-diastolic volume (EDV) and end-systolic volume (ESV) were underestimated by 14.8 +/- 10.6% (mean +/- SD) and 11.2 +/- 16.3%, respectively (r = 9.42, P < 0.001 and r = 0.937, P = 0.003); with the X3-1 system 24.2 +/- 11.0 and 14.6 +/- 15.2%, respectively (r = 0.951, P < 0.001 and r = 0.912, P = 0.001). Negligible differences <1% (P = n.s.) between both transducers were detected applying a tCFA value of 70 U but with significant underestimation (EDV: approximately 35%, P < 0.001; ESV: approximately 26%, P < 0.001) compared with CMR. EDV and ESV of TOF patients were underestimated by 3.2 +/- 15.4 and 8.1 +/- 22.6%, respectively. Intra- and interobserver variability was <4%. In contrast to recommendations of the manufacturer, data sets from both RT3DE transducers showed acceptable agreement to CMR for volumetric parameters only for low tCFA. Fine-tuning of software settings is mandatory to improve accuracy.

The use of real-time three-dimensional echocardiography for the quantification of left ventricular volumes and function

The purpose of this review is to provide readers with an update on the latest developments and the current status of the real-time three-dimensional echocardiographic (RT3DE) quantitative evaluation of left ventricular volumes and function. In recent years, the growing availability of RT3DE imaging technology, its ease of use and its multiple attractive features have sparked significant interest in the echocardiography community, resulting in a large number of research papers, most of which have endorsed RT3DE imaging for clinical use by demonstrating its unique capabilities in different scenarios. In parallel, the clinical acceptance of this new tool has broadened significantly. Although the clinical value of RT3DE evaluation of the left ventricle is already well established, future improvements will determine whether this methodology can become the new standard reference technique for accurate and repeatable measurement of left ventricular volumes, mass, regional left ventricular function and dyssynchrony.

Left ventricular non-compaction: clinical features and cardiovascular magnetic resonance imaging

BackgroundIt is apparent that despite lack of family history, patients with the morphological characteristics of left ventricular non-compaction develop arrhythmias, thrombo-embolism and left ventricular dysfunction.MethodsForty two patients, aged 48.7 ± 2.3 yrs (mean ± SEM) underwent cardiovascular magnetic resonance (CMR) for the quantification of left ventricular volumes and extent of non-compacted (NC) myocardium. The latter was quantified using planimetry on the two-chamber long axis LV view (NC area). The patients included those referred specifically for CMR to investigate suspected cardiomyopathy, and as such is represents a selected group of patients.ResultsAt presentation, 50% had dyspnoea, 19% chest pain, 14% palpitations and 5% stroke. Pulmonary embolism had occurred in 7% and brachial artery embolism in 2%. The ECG was abnormal in 81% and atrial fibrillation occurred in 29%. Transthoracic echocardiograms showed features of NC in only 10%. On CMR, patients who presented with dyspnoea had greater left ventricular volumes (both p < 0.0001) and a lower left ventricular ejection fraction (LVEF) (p < 0.0001) than age-matched, healthy controls. In patients without dyspnoea (n = 21), NC area correlated positively with end-diastolic volume (r = 0.52, p = 0.0184) and end-systolic volume (r = 0.56, p = 0.0095), and negatively with EF (r = -0.72, p = 0.0001).ConclusionLeft ventricular non-compaction is associated with dysrrhythmias, thromboembolic events, chest pain and LV dysfunction. The inverse correlation between NC area and EF suggests that NC contributes to left ventricular dysfunction.

Quantification of left ventricular volumes using three-dimensional echocardiographic speckle tracking: comparison with MRI

Although the utility of two-dimensional (2D) speckle tracking echocardiography (STE) to quantify left ventricular (LV) volume has been demonstrated, this methodology is limited by foreshortened views, geometric modelling, and the assumption that speckles can be tracked from frame to frame, despite their out of plane motion. To circumvent these limitations, a three-dimensional (3D) speckle tracking algorithm was recently developed. Our goal was to evaluate the accuracy of the new 3D-STE side by side with 2D-STE using cardiac magnetic resonance (CMR) as a reference. Apical two- and four-chamber views (A2C and A4C) and real-time 3D datasets (Toshiba Artida 4D System) obtained in 43 patients with a wide range of LV size and function were analysed to measure LV end-systolic and end-diastolic volumes (ESV and EDV) using 2D and 3D-STE techniques. Short-axis CMR images (Siemens 1.5T scanner) acquired on the same day were analysed to obtain ESV and EDV reference values using the method of disks approximation. Reproducibility of both STE techniques was assessed using repeated measurements. While 2D-STE correlated well with CMR (r: 0.72-0.88), it underestimated LV volumes with relatively large biases (10-30 mL) and wide limits of agreement (SD: 36-51 mL), with A2C-derived measurements being worse than A4C values. The 3D-STE measurements showed higher correlation with CMR (0.87-0.92), and importantly smaller biases (1-16 mL) and narrower limits of agreement (SD: 28-37 mL). In addition, 3D-STE showed lower inter- and intra-observer variability (11-14% and 12-13%), than 2D-STE (16-17% and 12-16%, respectively). This is the first study to validate the new 3D-STE technique for LV volume measurements and demonstrate its superior accuracy and reproducibility over previously used 2D-STE technique.

Semi-automated quantification of left ventricular volumes and ejection fraction by real-time three-dimensional echocardiography

BackgroundRecent studies have shown that real-time three-dimensional (3D) echocardiography (RT3DE) gives more accurate and reproducible left ventricular (LV) volume and ejection fraction (EF) measurements than traditional two-dimensional methods. A new semi-automated tool (4DLVQ) for volume measurements in RT3DE has been developed. We sought to evaluate the accuracy and repeatability of this method compared to a 3D echo standard.MethodsLV end-diastolic volumes (EDV), end-systolic volumes (ESV), and EF measured using 4DLVQ were compared with a commercially available semi-automated analysis tool (TomTec 4D LV-Analysis ver. 2.2) in 35 patients. Repeated measurements were performed to investigate inter- and intra-observer variability.ResultsAverage analysis time of the new tool was 141s, significantly shorter than 261s using TomTec (p < 0.001). Bland Altman analysis revealed high agreement of measured EDV, ESV, and EF compared to TomTec (p = NS), with bias and 95% limits of agreement of 2.1 ± 21 ml, -0.88 ± 17 ml, and 1.6 ± 11% for EDV, ESV, and EF respectively. Intra-observer variability of 4DLVQ vs. TomTec was 7.5 ± 6.2 ml vs. 7.7 ± 7.3 ml for EDV, 5.5 ± 5.6 ml vs. 5.0 ± 5.9 ml for ESV, and 3.0 ± 2.7% vs. 2.1 ± 2.0% for EF (p = NS). The inter-observer variability of 4DLVQ vs. TomTec was 9.0 ± 5.9 ml vs. 17 ± 6.3 ml for EDV (p < 0.05), 5.0 ± 3.6 ml vs. 12 ± 7.7 ml for ESV (p < 0.05), and 2.7 ± 2.8% vs. 3.0 ± 2.1% for EF (p = NS).ConclusionIn conclusion, the new analysis tool gives rapid and reproducible measurements of LV volumes and EF, with good agreement compared to another RT3DE volume quantification tool.

Real-Time 3-Dimensional Echocardiography

One of the most significant developments of the last decade in ultrasound imaging of the heart was the evolution of 3-dimensional (3D) imaging from slow and labor-intense offline reconstruction to real-time volumetric imaging. This imaging modality provides valuable clinical information that empowers echocardiographers with new levels of confidence in the diagnosis of heart disease. We have previously described the technological milestones in the development of real-time 3D echocardiographic (RT3DE) imaging and its major advantages over conventional 2-dimensional echocardiography (2DE) and reviewed the published literature that supported the use of this new methodology in clinical practice.1 Since 2006, the growing availability of RT3DE technology, its ease of use, and its multiple attractive features have sparked significant interest in the research community, resulting in a large number of publications, most of which have endorsed RT3DE imaging for clinical use by demonstrating its unique capabilities in different scenarios. In parallel, the clinical acceptance of this new tool has broadened significantly. The most recent clinically significant addition is matrix-array transesophageal echocardiography (TEE), which provides images of unprecedented quality that aid surgeons and interventional cardiologists in planning and guiding procedures and evaluating their outcomes. The purpose of the present article is to review the most recent RT3DE literature and provide readers with an update on the latest developments and the current status of this noninvasive imaging tool. Because different potential applications of RT3DE imaging have been explored to various extents, they are described here separately, and each is discussed with an emphasis on the scientifically established facts, along with the known stumbling blocks and difficulties. A firmly established advantage of 3D imaging over cross-sectional slices of the heart is the improvement in the accuracy of the evaluation of left ventricular (LV) volumes and ejection fraction (EF) by eliminating the need for geometric modeling, which …

Quantification of Left Ventricular Volumes and Ejection Fraction in Mice Using PET, Compared with MRI

PET has become an important noninvasive imaging technique in cardiovascular research for the characterization of mouse models in vivo. This modality offers unique insight into biochemical changes on a molecular level, with excellent sensitivity. However, morphologic and functional changes may be of equal importance for a thorough assessment of left ventricular (LV) pathophysiology. Although echocardiography and MRI are widely considered the imaging techniques of choice for the assessment of these parameters, their use with PET considerably increases study complexity and decreases cost- and time-efficiency. In this study, a novel method for the additional quantification of LV volumes and ejection fraction (EF) from PET was evaluated using cardiac MRI as the reference method. The radiolabeled glucose derivative 18F-FDG was injected into 33 mice (6 mice with previous permanent occlusion of the left anterior descending artery [LAD], 15 mice with a temporary 30-min occlusion of the LAD, and 12 mice without previous surgery). 18F-FDG uptake within the LV myocardium was measured using a dedicated small-animal PET scanner. After we reconstructed the images into 16 electrocardiogram (ECG)-gated frames, we determined the LV cavity volumes in end-diastole (EDV) and end-systole (ESV) and the EF using a semiautomatic segmentation algorithm based on elastic surfaces. A 6.3-T cardiac MRI examination was performed in the same animals using an ECG-triggered and respiratory-gated multislice cine sequence. The MR images were segmented with a semiautomatic algorithm using commercially available software. Overall, measurements from PET agreed well with those obtained by MRI. Mean EDV and ESV were slightly overestimated by PET (86+/-43 microL and 44+/-42 microL), compared with MRI (73+/-44 microL and 41+/-46 microL); mean (+/-SD) EF was similar (PET, 55+/-19 microL; MRI, 54+/-18 microL). Correlation between PET and MRI was excellent for EDV (0.97) and ESV (0.96) and good for EF (0.86). The slope of the regression line was nearly perfect for EDV (0.98) and EF (1.01) and slightly below 1 for ESV (0.90), indicating a good separation of abnormal and normal values with PET. The y-intercept was above zero for EDV (15 microL) and ESV (7 microL) and near to zero for EF (0.2%). The quantification of LV volumes and EF in mice with PET is both efficient and accurate. This method allows for combined molecular and functional imaging of the left ventricle within a single scan, obviating additional sophisticated MRI in many cases.

Usefulness of three-dimensional automated quantification of left ventricular mass, volume, and function by 64-slice computed tomography

Quantification of left ventricular (LV) mass has important prognostic implications. However, accurate measurement of LV mass has been difficult, in part because of the oblique angle at which the heart lies within the chest and the continuous movement of the heart itself. Multislice computed tomography (MSCT) allows assessment not only of coronary stenosis but LV volume, function, and mass. A novel three-dimensional (3D) region-growing-based semi-automated segmentation algorithm for measurements of LV mass, volume, and function was recently developed. This study evaluated this new 3D automated method for measurement of LV mass, by comparison with a well-established 2D manual contour-drawing algorithm. The study population consisted of 50 consecutive patients who underwent ECG-gated MSCT for evaluation of coronary arteries. The 3D algorithm for reliable segmentation was unsuccessful in two patients. In the remaining 48 patients, however, LV segmentation using this algorithm was performed and delivered visually reliable segmentation results. The 3D algorithm for analysis of LV function and mass is feasible based on volumetric data, and exhibits good correlation and agreement with the results obtained with the conventional 2D algorithm. The time required for the new automated algorithm was significantly shorter than that for the manual contour-drawing algorithm (P<0.0001) (automated algorithm: 468.0±205.1 s, manual algorithm: 1362.4±410.5 s, mean ±S.D.). The 3D semi-automated region-growing segmentation algorithm for analysis of LV function and mass is feasible based on volumetric data, and exhibits good correlations and agreement with the results of the conventional 2D manual contour-drawing algorithm.

Die Rolle der Magnetresonanztomografie bei erwachsenen Patienten mit angeborenen Herzfehlern

Congenital heart disease (CHD) occurs in approximately 0.8 % of live newborns. Today, more than 80 % of these patients reach adulthood, creating a growing population of grown-ups with congenital heart disease (GUCH). According to recent data, the number of adults with surgically treated CHD living in Germany is about 180 000. These patients require lifelong follow-ups, ideally provided by pediatric heart specialists and cardiologists together. Due to distinct advantages and rapid technological progress over the last three decades, CMR has evolved as first-line diagnostic tool in management of GUCH patients. In addition to the generation of high-resolution images in any orientation, CMR also is capable of retrieving functional information, e. g. quantification of ventricular function and volume, as well as valve (mal-)function, shunts, extracardiac connections etc. At this stage, CMR has emerged as an accurate imaging technique with widespread clinical implications. It can be expected that recent progress and development will even raise the clinical and diagnostic impact of CMR.

Rapid and Accurate Quantification of Right Ventricular Volume and Stroke Volume by Real‐time 3‐Dimensional Triplane Echocardiography

Previous studies have demonstrated that 3-Dimensional (3-D) echocardiography can determine right ventricular (RV) volume accurately. However, this technique has not been feasible in everyday clinical practice because of the necessity of time-consuming off-line processes. A newly developed real-time 3-D triplane echocardiography, which acquires 3 apical rotational cross-sectional images simultaneously, holds the promise to resolve these problems. Sixteen excised formalin fixed porcine hearts and 24 healthy human subjects underwent real-time 3-D triplane echocardiography. In an anatomic in vitro study, the actual volume of RV was obtained by spilling water in the RV cavity into a graduated cylinder for measurement, which served as a reference standard for comparison. For healthy subjects, the RV stroke volume (SV) was measured by triplane echocardiography which was compared with the left ventricular (LV) SV obtained by conventional 2-Dimensional echocardiography (2-DE). Excellent correlation and agreement between 3-D triplane imaging derived RV volume and the actual one for excised porcine hearts were observed (r = 0.979, p < 0.001, mean difference 2.2 mL). In healthy human subjects, good correlation and agreement between 3-D triplane imaging derived RV SV and LV SV measured by 2-DE were obtained (r = 0.970, p < 0.001, mean difference 5.9 mL). Real-time 3-D triplane echocardiography provides us a new method for rapid and accurate quantification of RV volume. Furthermore, this new method holds the promise for evaluating RV volume and SV in routine clinical practice.

Real-Time 3-Dimensional Echocardiographic Quantification of Left Ventricular Volumes: Multicenter Study for Validation With Magnetic Resonance Imaging and Investigation of Sources of Error

We sought to study: 1) the accuracy and reproducibility of real-time 3-dimensional echocardiographic (RT3DE) analysis of left ventricular (LV) volumes in a multicenter setting, 2) interinstitutional differences in relationship with the investigators' specific experience, and 3) potential sources of volume underestimation. Reproducibility and accuracy of RT3DE evaluation of LV volumes has not been validated in multicenter studies, and LV volumes have been reported to be underestimated compared to cardiac magnetic resonance (CMR) standard. A total of 92 patients with a wide range of ejection fractions underwent CMR and RT3DE imaging at 4 different institutions. Images were analyzed to obtain LV end-systolic volume (ESV) and end-diastolic volume (EDV). Reproducibility was assessed using repeated analyses. The investigation of potential sources of error included: phantom imaging, intermodality analysis-related differences, and differences in LV boundary identification, such as inclusion of endocardial trabeculae and mitral valve plane in the LV volume. The RT3DE-derived LV volumes correlated highly with CMR values (EDV: r = 0.91; ESV: r = 0.93), but were 26% and 29% lower consistently across institutions, with the magnitude of the bias being inversely related to the level of experience. The RT3DE measurements were less reproducible (4% to 13%) than CMR measurements (4% to 7%). Minimal changes in endocardial surface position (1 mm) resulted in significant differences in measured volumes (11%). Exclusion of trabeculae and mitral valve plane from the CMR reference eliminated the intermodality bias. The RT3DE-derived LV volumes are underestimated in most patients because RT3DE imaging cannot differentiate between the myocardium and trabeculae. To minimize this difference, tracing the endocardium to include trabeculae in the LV cavity is recommended. With the understanding of these intermodality differences, RT3DE quantification of LV volume is a reliable tool that provides clinically useful information.

From anatomy to function: the developing image of ultrasound evaluation

From anatomy to function: the developing image of ultrasound evaluation

Exactitud de distintos métodos de segmentación para cuantificar parámetros de función cardiaca y masa ventricular izquierda en un modelo animal

To evaluate accuracy of manual, semiautomatic and automatic segmentation methods to quantify cardiac function parameters, volumes, and left ventricular mass. Ten Goettingen miniature pigs (seven male, three female; mean weight 49.8 kg; SD: 10.65; range: 35-65 kg) were evaluated using a 1.5 Tesla MR scanner and free-breathing SSFP sequences. Short axis images were employed to quantify cardiac parameters. In all animals volumes (end-diastolic volume, end-sisstolic volume, stroke volume), ejection fraction and left ventricular mass was calculated. To quantify these parameters three different segmentation methods (manual, semiautomatic, and automatic) were employed. The correlation of different segmentation methods for each variable was analyzed. No statistically significant differences in left ventricular volume or mass quantification using different segmentation methods was found (p > 0.05). Correlation to estimate ejection fraction and end-diastolic volume was good (r > 0.6) and turned to be excellent for the rest of the variables (r > 0.8). Mean quantification time was less for semiautomatic and automatic methods than for the manual method. SSFP sequences allow to accurately evaluate cardiac function parameters and left ventricular mass in a large animal model with any of the segmentation method described in this report. Non-manual segmentation methods allow rapid quantification of cardiac parameters.

Quantitative assessment of left ventricular function with dual-source CT in comparison to cardiac magnetic resonance imaging: initial findings

Cardiac magnetic resonance imaging and echocardiography are currently regarded as standard modalities for the quantification of left ventricular volumes and ejection fraction. With the recent introduction of dual-source computedtomography (DSCT), the increased temporal resolution of 83 ms should also improve the assessment of cardiac function in CT. The aim of this study was to evaluate the accuracy of DSCT in the assessment of left ventricular functional parameters with cardiac magnetic resonance imaging (MRI) as standard of reference. Fifteen patients (two female, 13 male; mean age 50.8 +/- 19.2 years) underwent CT and MRI examinations on a DSCT (Somatom Definition; Siemens Medical Solutions, Forchheim, Germany) and a 3.0-Tesla MR scanner (Magnetom Trio; Siemens Medical Solutions), respectively. Multiphase axial CT images were analysed with a semiautomatic region growing algorithms (Syngo Circulation; Siemens Medical Solutions) by two independent blinded observers. In MRI, dynamic cine loops of short axis slices were evaluated with semiautomatic contour detection software (ARGUS; Siemens Medical Solutions) independently by two readers. End-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF) and stroke volume (SV) were determined for both modalities, and correlation coefficient, systematic error, limits of agreement and inter-observer variability were assessed. In DSCT, EDV and ESV were 135.8 +/- 41.9 ml and 54.9 +/- 29.6 ml, respectively, compared with 132.1 +/- 40.8 ml EDV and 57.6 +/- 27.3 ml ESV in MRI. Thus, EDV was overestimated by 3.7 ml (limits of agreement -46.1/+53.6), while ESV was underestimated by 2.6 ml (-36.6/+31.4). Mean EF was 61.6 +/- 12.4% in DSCT and 57.9 +/- 9.0% in MRI, resulting in an overestimation of EF by 3.8% with limits of agreement at -14.7 and +22.2%. Rank correlation rho values were 0.81 for EDV (P = 0.0024), 0.79 for ESV (P = 0.0031) and 0.64 for EF (P = 0.0168). The kappa value of inter-observer variability were amounted to 0.85 for EDV, ESV and EF. DSCT offers the possibility to quantify left ventricular function from coronary CT angiography datasets with sufficient diagnostic accuracy, adding to the value of the modality in a comprehensive cardiac assessment. The observed differences in the measured values may be due to different post-processing methods and physiological reactions to contrast material injection without beta-blocker medication.

Balanced steady‐state free precession vs. segmented fast low‐angle shot for the evaluation of ventricular volumes, mass, and function at 3 Tesla

To compare balanced steady-state free precession (SSFP) and segmented fast low angle shot (FLASH) for quantification of left and right ventricular volumes and function and for left ventricular mass at high field (3 Tesla). A total of 33 patients (19 male, mean age 54 years) with various forms of heart disease underwent ventricular function studies using cine SSFP and FLASH sequences with identical slice orientations. Using SSFP, left ventricular end-diastolic (+10 mL [4.7%], P < 0.001) and end-systolic volumes (+9 mL [6.1%], P < 0.001) measured larger whereas mass was considerably smaller (-23 g [-12.9%], P < 0.001) and ejection fraction (-1% [-3.2%], P < 0.01) marginally smaller. Right ventricular end-diastolic (+4 mL [2.6%], P = 0.001) and end-systolic volumes (+4 mL [5.1%], P < 0.01) were also larger, but no significant difference for right ventricular ejection fraction (P = 0.05) was found. Similar to previous results at 1.5 Tesla, at high magnetic field the cine SSFP technique led to discrete but significantly higher ventricular volume measurements and to a significantly smaller measurement of left ventricular mass in patients. The effect on left and right ventricular ejection fraction was minor, although the difference remained significant for the left ventricle.

Quantification of Left Ventricular Volumes and Function in Patients with Cardiomyopathies by Real-time Three-dimensional Echocardiography: A Head-to-Head Comparison Between Two Different Semiautomated Endocardial Border Detection Algorithms

We evaluated two different commercially available real-time 3-dimensional echocardiographic semiautomated border detection algorithms for left ventricular (LV) volume analysis in patients with cardiomyopathy and distorted LV geometry. A total of 53 patients in sinus rhythm with various types of cardiomyopathy (mean age 56 +/- 11 years, 28 men) and adequate 2-dimensional image quality were included. The real-time 3-dimensional echocardiographic multiplane interpolation (MI) and full volume reconstruction (FVR) methods were used for LV volume analysis. Magnetic resonance imaging was used as the reference method. A strong correlation (R(2) > 0.95) was found for all LV volume and ejection fraction measurements by either real-time 3-dimensional echocardiographic method. Analysis time was shorter with the FVR method (6 +/- 2 vs 15 +/- 4 minutes, P < .01) as compared with the MI method. Bland-Altman analysis showed greater underestimation of end-diastolic and end-systolic volumes by MI compared with FVR. For the MI method a bias of -24.0 mL (-15.0% of the mean) for end-diastolic volume and -11.3 mL (-18.0% of the mean) for end-systolic volume was found. For FVR analysis these values were -9.9 mL (-6.0% of the mean) and -5.0 mL (-9.0% of the mean), respectively. Ejection fraction was similar for the MI and FVR method with a mean difference compared with magnetic resonance imaging of 0.6 (1.0%) and 0.8 (1.3%), respectively. In patients with cardiomyopathy, distorted LV geometry, and good 2-dimensional image quality, the FVR method is faster and more accurate than the MI method in assessment of LV volumes.

How Many Planes Are Required to Get an Accurate and Timesaving Measurement of Left Ventricular Volume and Function by Real-Time Three-Dimensional Echocardiography in Acute Myocardial Infarction?

To derive the optimal cutting planes of real-time 3-D echocardiography (RT-3DE) for measuring left ventricular volume and ejection fraction (EF) in the presence of left ventricular regional wall motion abnormalities, 14 open-chest dogs were studied with RT-3DE full volume imaging and 2-D echocardiography (2DE) after left anterior descending coronary arteries were occluded for 90 min. Left ventricular end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV) and EF were measured off-line with 2DE and RT-3DE (2-, 4- and 8-plane) methods. The autopsy EDV was estimated by the volume of saline solution injected into the excised heart and served as the reference volume (RefV) for comparison with EDV measured by 2DE and RT-3DE. Agreement analysis was performed according to the method of Bland and Altman. There were excellent correlations between 2DE, RT-3DE (2-plane) and RT-3DE (4-plane) methods on one hand, and RT-3DE (8-plane) method on the other in the measurements of EDV, ESV and SV (r = 0.84–0.99). However, 2DE and RT-3DE (2-plane) measurements significantly underestimated RT-3DE (8-plane) ( p < 0.01), whereas no significant differences between RT-3DE (4-plane) and RT-3DE (8-plane) were found in terms of EDV, ESV and SV measurements. The values of EF determined by 2DE, RT-3DE (2-plane) and RT-3DE (4-plane) methods correlated highly with that by RT-3DE (8-plane) (r = 0.82–0.98) and there was no significant difference between the two measurements. EDV values determined by 2DE, RT-3DE (2-plane), RT-3DE (4-plane) and RT-3DE (8-plane) correlated highly with RefV (r = 0.84, r = 0.92, r = 0.94 and r = 0.97, respectively) and there was no significant difference between RefV and EDV by RT-3DE (4-plane) and RT-3DE (8-plane). In contrast, EDV measured by 2DE and RT-3DE (2-plane) methods underestimated RefV significantly ( p < 0.01). In conclusion, RT-3DE allows reliable and reproducible measurement of left ventricular volume and EF, even in the presence of left ventricular regional wall motion abnormalities. RT-3DE (4-plane) is the method of choice for an accurate and timesaving quantification of left ventricular volume and function. (E-mail: zhangyun@sdu.edu.cn)

A Comparison between QLAB and TomTec Full Volume Reconstruction for Real Time Three‐Dimensional Echocardiographic Quantification of Left Ventricular Volumes

To compare the interobserver variability and accuracy of two different real time three-dimensional echocardiography (RT3DE) analyzing programs. Forty-one patients (mean age 56 +/- 11 years, 28 men) in sinus rhythm with a cardiomyopathy and adequate 2D image quality underwent RT3DE and magnetic resonance imaging (MRI) within one day. Off-line left ventricular (LV) volume analysis was performed with QLAB V4.2 (semiautomated border detection with biplane projections) and TomTec 4D LV analysis V2.0 (primarily manual tracking with triplane projections and semiautomated border detection). Excellent correlations (R(2) > 0.98) were found between MRI and RT3DE. Bland-Altman analysis revealed an underestimated LV end-diastolic volume (LV-EDV) for both TomTec (-9.4 +/- 8.7 mL) and QLAB (-16.4 +/- 13.1 ml). Also, an underestimated LV end-systolic volume (LV-ESV) for both TomTec (-4.8 +/- 9.9 mL) and QLAB (-8.5 +/- 14.2 mL) was found. LV-EDV and LV-ESV were significantly more underestimated with QLAB software. Both programs accurately calculated LV ejection fraction (LV-EF) without a bias. Interobserver variability was 6.4 +/- 7.8% vs. 12.2 +/- 10.1% for LV-EDV, 7.8 +/- 9.7% vs. 13.6 +/- 11.2% for LV-ESV, and 7.1 +/- 6.9% vs. 9.7 +/- 8.8% for LV-EF for TomTec vs. QLAB, respectively. The analysis time was shorter with QLAB (4 +/- 2 minutes vs. 6 +/- 2 minutes, P < 0.05). RT3DE with TomTec or QLAB software analysis provides accurate LV-EF assessment in cardiomyopathic patients with distorted LV geometry and adequate 2D image quality. However, LV volumes may be somewhat more underestimated with the current QLAB software version.