Comparison of two- and three-dimensional echocardiography with sequential magnetic resonance imaging for evaluating left ventricular volume and ejection fraction over time in patients with healed myocardial infarction

Echocardiographic follow-up of left ventricular (LV) volumes is difficult because of the test-retest variation of 2-dimensional echocardiography (2DE). We investigated whether the accuracy and reproducibility of real-time 3-dimensional echocardiography (RT3DE) would make this modality more feasible for serial follow-up of LV measurements. We performed 2DE and RT3DE and cardiac magnetic resonance imaging (MRI) in 50 patients with previous infarction and varying degrees of LV function (44 men; 61 +/- 11 years of age) at baseline and after 1-year follow-up. Images were obtained during breath-hold and measurements of LV volumes and ejection fraction were made offline. Over follow-up, end-diastolic volume decreased from 192 +/- 53 to 187 +/- 60 ml (p <0.01), end-systolic volume decreased from 104 +/- 51 to 95 +/- 53 ml (p <0.01), and ejection fraction increased from 48 +/- 12% to 51 +/- 12% (p <0.01). MRI showed that LV mass shrank from 183 +/- 39 to 182 +/- 37 g (p <0.01). The correlation between change in RT3DE and change in MRI was greater than the correlations of 2DE with MRI for measurement of end-diastolic volume (r = 0.47 vs 0.02, p <0.01), end-systolic volume (r = 0.44 vs 0.17, p <0.01), and ejection fraction (r = 0.58 vs -0.03, p <0.01). The change in end-diastolic volume between baseline and follow-up with RT3DE (-4 +/- 20, p <0.01) was similar to that with MRI but was unrecognized by 2DE (4 +/- 19, p = 0.09). There was good test-retest and inter- and intraobserver correlation within RT3DE for volumes, ejection fraction, and mass. In conclusion, if sequential measurement of LV volumes is used to guide management decisions, 3DE appears preferable to 2DE.     

Comparison of contrast agent-enhanced versus non-contrast agent-enhanced real-time three-dimensional echocardiography for analysis of left ventricular systolic function

Ultrasound contrast has shown to improve endocardial border definition. The purpose of this study was to evaluate the value of contrast agent-enhanced versus non-contrast agent-enhanced real-time 3-dimensional echocardiography (RT3DE) for the assessment of left ventricular (LV) volumes and ejection fraction. Thirty-nine unselected patients underwent RT3DE with and without SonoVue contrast agent enhancement and magnetic resonance imaging (MRI) on the same day. An image quality index was calculated by grading all 16 individual LV segments on a scale of 0 to 4: 0, not visible; 1, poor; 2, moderate; 3, good; and 4, excellent. The 3-dimensional data sets were analyzed offline using dedicated TomTec analysis software. By manual tracing, LV end-systolic volume, LV end-diastolic volume, and LV ejection fraction were calculated. After contrast agent enhancement, mean image quality index improved from 2.4 +/- 1.0 to 3.0 +/- 0.9 (p <0.001). Contrast agent-enhanced RT3DE measurements showed better correlation with MRI (LV end-diastolic volume, r = 0.97 vs 0.86; LV end-systolic volume, r = 0.96 vs 0.94; LV ejection fraction, r = 0.94 vs 0.81). The limits of agreement (Bland-Altman analysis) showed a similar bias for RT3DE images with and without contrast agent but with smaller limits of agreement for contrast agent-enhanced RT3DE. Also, inter- and intraobserver variabilities decreased. In a subgroup, patients with poor to moderate image quality showed an improvement in agreement after administration of contrast agent (+/-24.4% to +/-12.7%) to the same level as patients with moderate to good image quality without contrast agent (+/-10.4%). In conclusion, contrast agent-enhanced RT3DE is more accurate in assessment of LV function as evidenced by better correlation and narrower limits of agreement compared with MRI, as well as lower intra- and interobserver variabilities.     

Left ventricular volume measurement using cardiac axis nuclear magnetic resonance imaging. Validation by calibrated ventricular angiography

Proton nuclear magnetic resonance (NMR) imaging has the potential to serially assess left ventricular (LV) volumes with optimal accuracy because it is a high-resolution, three-dimensional, noninvasive modality. Previous NMR studies to assess LV volumes have been suboptimal, as they have used either planes aligned with the axes of the body, which are compromised by partial volume effects, or spin-echo techniques that have been time-consuming to acquire and analyze. Accordingly, for LV volume measurement, we developed a gradient-echo (cine) NMR strategy that uses two orthogonal planes intersecting along the intrinsic long axis of the heart (two-chamber and four-chamber). This approach was validated against calibrated contrast biplane LV cineangiography (CATH) and also compared with a previously reported short-axis spin-echo NMR method. Twenty-one patients underwent CATH and NMR (long-axis, n = 21; short-axis, n = 14) within a 3-day interval. Although both long- and short-axis NMR LV volumes and ejection fractions correlated well with CATH (r greater than 0.90, p less than 0.001 in all), end-diastolic volumes by both long-axis (161 +/- 85 ml) and short-axis (151 +/- 81 ml) NMR were systematically less than those by CATH (182 +/- 85 ml) (p less than 0.05). Consequently, ejection fractions by long-axis (48 +/- 17%) and short-axis (49 +/- 17%) NMR consistently underestimated those by CATH (54 +/- 16%, p less than 0.05). End-systolic volumes by long-axis (94 +/- 71 ml) and short-axis (87 +/- 72 ml) NMR were not significantly different from those by CATH (92 +/- 69 ml). Both NMR techniques had low intraobserver and interobserver variation (less than 11%); however, short-axis spin-echo NMR involved longer acquisition/reconstruction (35 versus 18 minutes) and analysis (25 versus 10 minutes) times. We conclude that both short-axis spin-echo and long-axis gradient-echo NMR approaches reliably estimate LV volumes. Currently, the long-axis strategy appears more practical for clinical use because the scan and analysis times are relatively short.     

Fast Data Acquisition and Analysis with Real Time Triplane Echocardiography for the Assessment of Left Ventricular Size and Function: A Validation Study

Aims: To assess accuracy and reproducibility of real time simultaneous triplane echocardiography (RT3PE) for the assessment of left ventricular (LV) volumes and ejection fraction (EF) using cardiac magnetic resonance (CMR) as a reference method. Methods and Results: A total of 24 patients with various degrees of LV dysfunction (EF from 36 to 57%) in sinus rhythm with good image quality were enrolled in the study. Digital loops of apical views were recorded with standard two-dimensional imaging and with RT3PE. Echocardiography and CMR were performed within 1 hour. RT3PE measurements of LV end-diastolic volume, end-systolic volume, and EF resulted closely correlated to CMR (r = 0.95, 0.97, and 0.95, respectively) with small biases (−4 ml, −6 ml, and 1%, respectively) and narrow limits of agreement (SD = 15 ml, 12 ml, and 6%, respectively). Two-dimensional echocardiography ( 2DE) showed a weaker correlation with CMR (r = 0.85, 0.91, and 0.83, respectively; P < 0.06) with similar biases (−4 ml, −10 ml, 5%, respectively), but wider limits of agreement (SD = 28 ml, 21 ml, 10%, respectively, P < 0.007). RT3PE showed lower interobserver variability for the assessment of EF (SD = 2% vs. 5%, P = 0.03) and lower measurement time of LV EF (175 ± 54 sec vs. 241 ± 49 sec, respectively; P < 0.0001), as compared to 2DE. Conclusion: RT3PE allows simple and fast image acquisition and volume calculation. In addition, it allows more accurate and reproducible EF measurements than conventional 2DE.     

Accuracy of measurement of left ventricular volume and ejection fraction by new real-time three-dimensional echocardiography in patients with wall motion abnormalities secondary to myocardial infarction

Three-dimensional echocardiography is an ideal tool for the measurement of left ventricular (LV) volume because no geometric assumptions about LV shape are needed. The introduction of new real-time 3-dimensional echocardiography (RT3DE) has allowed rapid acquisition of a 3-dimensional dataset with good image quality. The purpose of this study was to examine the accuracy of RT3DE for the measurement of LV volume and ejection fraction in patients with wall motion abnormalities by using quantitative gated single-photon emission computed tomography (QGSPECT) as a reference standard. The study population consisted of 25 consecutive patients with wall motion abnormalities who underwent LV volume measurement by 2-dimensional echocardiography and by QGSPECT. LV volume and ejection fraction by RT3DE were measured offline by using the average rotation method. In 23 of 25 patients (92%), it was possible to measure 3-dimensional volume with RT3DE. RT3DE correlated well with QGSPECT in the measurement of end-diastolic volume and end-systolic volume (r = 0.97, mean difference 3.4 ml; r = 0.98, mean difference 2.0 ml, respectively), 2-dimensional echocardiography also correlated with QGSPECT but underestimated LV volume (r = 0.98, mean difference 21.1 ml; r = 0.98, mean difference 15.6 ml, respectively). Ejection fraction obtained by RT3DE had better agreement with that obtained by QGSPECT than that obtained by 2-dimensional echocardiography (r = 0.92, mean difference -0.2%; r = 0.89, mean difference -2.7%, respectively). RT3DE allows convenient and accurate estimation of LV volume and ejection fraction in patients with wall motion abnormalities.     

Reproducibility and accuracy of echocardiographic measurements of left ventricular parameters using real-time three-dimensional echocardiography

OBJECTIVES: We sought to determine whether assessment of left ventricular (LV) function with real-time (RT) three-dimensional echocardiography (3DE) could reduce the variation of sequential LV measurements and provide greater accuracy than two-dimensional echocardiography (2DE). BACKGROUND: Real-time 3DE has become feasible as a standard clinical tool, but its accuracy for LV assessment has not been validated. METHODS: Unselected patients (n = 50; 41 men; age, 64 +/- 8 years) presenting for evaluation of LV function were studied with 2DE and RT-3DE. Test-retest variation was performed by a complete restudy by a separate sonographer within 1 h without alteration of hemodynamics or therapy. Magnetic resonance imaging (MRI) images were obtained during a breath-hold, and measurements were made off-line. RESULTS: The test-retest variation showed similar measurements for volumes but wider scatter of LV mass measurements with M-mode and 2DE than 3DE. The average MRI end-diastolic volume was 172 +/- 53 ml; LV volumes were underestimated by 2DE (mean difference, -54 +/- 33; p < 0.01) but only slightly by RT-3DE (-4 +/- 29; p = 0.31). Similarly, end-systolic volume by MRI (91 +/- 53 ml) was underestimated by 2DE (mean difference, -28 +/- 28; p < 0.01) and by RT-3DE (mean difference, -3 +/- 18; p = 0.23). Ejection fraction by MRI was similar by 2DE (p = 0.76) and RT-3DE (p = 0.74). Left ventricular mass (183 +/- 50 g) was overestimated by M-mode (mean difference, 68 +/- 86 g; p < 0.01) and 2DE (16 +/- 57; p = 0.04) but not RT-3DE (0 +/- 38 g; p = 0.94). There was good inter- and intra-observer correlation between RT-3DE by two sonographers for volumes, ejection fraction, and mass. CONCLUSIONS: Real-time 3DE is a feasible approach to reduce test-retest variation of LV volume, ejection fraction, and mass measurements in follow-up LV assessment in daily practice.     

Interstudy reproducibility of biplane cine nuclear magnetic resonance measurements of left ventricular function

Cine nuclear magnetic resonance (NMR) imaging, as a noninvasive and high-resolution imaging modality, has been shown to be reliable for determining absolute left ventricular (LV) volumes and ejection fraction. A relatively new gradient echo cine NMR approach using 2 orthogonal long-axis planes (2- and 4-chamber) aligned with the true axes of the left ventricle has been previously developed and validated against radiographic biplane LV cineangiography. The aim of the present investigation was to determine the reproducibility of this more rapid cine NMR approach for the measurement of LV volumes and ejection fraction. Eighteen normal subjects underwent 2 cine NMR studies, on different days, using a 1.5-tesla clinical imaging system. Studies were analyzed on-line and blindly by 2 independent observers. Intraobserver error was also determined in a blinded manner.

Mean values of measurements determined by this method in this group of normal subjects were end-diastolic volume (120 ± 20 ml), end-systolic volume (39 ± 9 ml) and ejection fraction (67 ± 4%). Paired analysis of data revealed no significant bias between interstudy, interobserver or intraobserver measurements, except for interobserver end-diastolic volume, where the first observer measurements were slightly elevated (5.6 ± 7.8 ml) compared with the second. This resulted in a small difference in ejection fraction (1.7 ± 2.3%) between observers. The absolute variation between measurements (square root of variance components) was low for all interstudy, interobserver and intraobserver comparisons: end-diastolic volume was <±6.7 ml, end-systolic volume <±3.5 ml and ejection fraction <±2.4%.

These results demonstrate the potential of the biplane cine NMR intrinsic long-axis approach to obtain reliable and sequential measurements of LV volumes and function in subjects without segmental wall motion abnormalities, using practical acquisition and analysis times.     

A comparison between QLAB and TomTec full volume reconstruction for real time three-dimensional echocardiographic quantification of left ventricular volumes

OBJECTIVES: To compare the interobserver variability and accuracy of two different real time three-dimensional echocardiography (RT3DE) analyzing programs. METHODS: 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). RESULTS: 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). CONCLUSIONS: 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.     

High-resolution transthoracic real-time three-dimensional echocardiography: quantitation of cardiac volumes and function using semi-automatic border detection and comparison with cardiac magnetic resonance imaging

OBJECTIVES: We sought to validate high-resolution transthoracic real-time (RT) three-dimensional echocardiography (3DE), in combination with a novel semi-automatic contour detection algorithm, for the assessment of left ventricular (LV) volumes and function in patients. BACKGROUND: Quantitative RT-3DE has been limited by impaired image quality and time-consuming manual data analysis. METHODS: Twenty-four subjects with abnormal (n = 14) or normal (n = 10) LVs were investigated. The results for end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) obtained by manual tracing were compared with the results determined by the semi-automatic border detection algorithm. Moreover, the results of the semi-automatic method were compared with volumes and EF obtained by cardiac magnetic resonance imaging (CMRI). RESULTS: Excellent correlation coefficients (r = 0.98 to 0.99) and low variability (EDV -1.3 +/- 8.6 ml; ESV -0.2 +/- 5.4 ml; EF -0.1 +/- 2.7%; p = NS) were observed between the semi-automatically and manually assessed data. The RT-3DE data correlated highly with CMRI (r = 0.98). However, LV volumes were underestimated by RT-3DE compared with CMRI (EDV -13.6 +/- 18.9 ml, p = 0.002; ESV -12.8 +/- 20.5 ml, p = 0.005). The difference for EF was not significant between the two methods (EF 0.9 +/- 4.4%, p = NS). Observer variability was acceptable, and repeatability of the method was excellent. CONCLUSIONS: The RT-3DE, in combination with a semi-automatic contour tracing algorithm, allows accurate determination of cardiac volumes and function compared with both manual tracing and CMRI. High repeatability suggests applicability of the method for the serial follow-up of patients with cardiac disease.     

Real time three-dimensional echocardiographic assessment of left ventricular function in heart failure patients: underestimation of left ventricular volume increases with the degree of dilatation

Background: Accurate quantification of left ventricular (LV) volumes and ejection fraction (EF) is of critical importance. Cardiac magnetic resonance (CMR) is considered as the reference and three-dimensional echocardiography (3DE) is an accurate method, but only few data are available in heart failure patients. We therefore sought to compare the accuracy of real time three-dimensional echocardiography (RT3DE) and two-dimensional echocardiography (2DE) for quantification of LV volumes and EF, relative to CMR imaging in an unselected population of heart failure patients. Methods and Results: We studied 24 patients (17 men, age 58 ± 15 years) with history of heart failure who underwent echocardiographic assessment of LV function (2DE, RT3DE) and CMR within a period of 24 hours. Mean LV end-diastolic volume (LVEDV) was 208 ± 109 mL (121 ± 64 mL/m(2) ) and mean LVEF was 31 ± 12.8%. 3DE data sets correlate well with CMR, particularly with respect to the EF (r: 0.8, 0.86, and 0.95; P < 0.0001 for LVEDV, LVESV, and EF, respectively) with small biases (-55 mL, -44 mL, 1.1%) and acceptable limits of agreement. RT3DE provides more accurate measurements of LVEF than 2DE (z= 2.1, P = 0.037) and lower variability. However, 3DE-derived LV volumes are significantly underestimated in patients with severe LV dilatation. In patients with LVEDV below 120 mL/m(2) , RT3DE is more accurate for volumes and EF evaluation. Conclusion: Compared with CMR, RT3DE is accurate for evaluation of EF and feasible in all our heart failure patients, at the expense of a significant underestimation of LV volumes, particularly when LVEDV is above 120 mL/m(2) .     

Two-dimensional echocardiographic assessment of left ventricular function in chronic obstructive pulmonary disease

In 10 patients undergoing therapy for a mild exacerbation of their chronic obstructive pulmonary disease (COPD), a quantitative two-dimensional echocardiographic (2DE) study was performed together with hemodynamics to assess left ventricular (LV) function. From the 2DE examination, which was made up of parasternal, subcostal, and apical views, measurements of LV short axis end-diastolic and end-systolic areas (A) at the high papillary muscle level and long axis end-diastolic and end-systolic length (L) permitted us to calculate LV end-systolic and end-diastolic volumes (V) using the formula V = 5/6 AL. Compared with the same measurements obtained in a group of 12 normal volunteers, patients with COPD exhibited a markedly reduced LV cavity (LVES, 28.9 +/- 14.6 ml/m2 versus 51.5 +/- 11.0 ml/m2; LVEDV, 67.7 +/- 24.6 ml/m2 versus 103.2 +/- 19.9 ml/m2). An increased thickness of both left ventricular free wall and interventricular septum was also evidenced in patients with COPD. Left ventricular systolic function, assessed using both peak systolic blood pressure/end-systolic volume ratio and calculated left ventricular ejection fraction, was found to be clearly enhanced in patients with COPD. The influence of right ventricular enlargement on left ventricular diastolic function was also investigated in patients with COPD using progressive volume loading and 2DE right ventricular measurements. After a given threshold of volume loading, reduction in stroke index, opposite variations in right and left ventricular size and septal flattening, suggested the occurrence of ventricular interaction.     

Quantitative analysis of right ventricular function in patients with pulmonary hypertension using three-dimensional echocardiography and a two-dimensional summation method compared to magnetic resonance imaging

Magnetic resonance imaging (MRI) is considered the clinical reference standard for measuring the right ventricular (RV) volume and ejection fraction, although real-time 3-dimensional echocardiography (RT3DE) would be a preferred method owing to its convenience and availability for repetitive examinations. However, the feasibility, accuracy, and reproducibility of RT3DE have not been fully examined. The present study sought to validate the correlation of RT3DE with a 2-dimensional summation method compared to MRI for assessing the function of the right ventricle and to evaluate the RV function in patients with pulmonary hypertension (PH). Thirty patients with PH underwent both RT3DE and MRI. The right ventricle was reconstructed with RT3DE using a 2-dimensional summation method to analyze the MRI measurements. The RV end-diastolic volume, RV end-systolic volume, and RV ejection fraction were measured. Fifteen normal subjects underwent the same echocardiographic protocol for comparison. The RV end-diastolic volume index, RV end-systolic volume index, and RV ejection fraction measured using RT3DE correlated well with those measured using MRI (R = 0.96, p <0.001; R = 0.96, p <0.001; p = 0.93, and p <0.001, respectively). All inter- and intraobserver variability values for the RV end-diastolic volume, RV end-systolic volume, and RV ejection fraction were <17%. Both the RV end-diastolic volume index and the RV end-systolic volume index were significantly enlarged in those with PH compared to those in the normal subjects (RVEDVI 123 ± 42 ml/m2 vs 74 ± 12 ml/m2; RVESVI 86 ± 33 ml/m2 vs 26 ± 5 ml/m2 in those with PH and the normal subjects, respectively, p <0.0001). In contrast, the RV ejection fraction was significantly reduced in the patients with PH compared to that in the normal subjects (30 ± 12% vs 65 ± 6%, respectively, p <0.01). Thus, RT3DE with a 2-dimensional summation method might provide comparable and feasible measurements of the RV volume in patients with PH compared to MRI.     

Left ventricular volume determined echocardiographically by assuming a constant left ventricular epicardial long-axis/short-axis dimension ratio throughout the cardiac cycle.

OBJECTIVES. The purpose of this study was to develop and test a simplified echocardiographic method to calculate left ventricular volume. BACKGROUND. This method was based on the assumption that the ratio of the left ventricular epicardial long-axis dimension to the epicardial short-axis dimension was constant throughout the cardiac cycle. With use of this constant ratio, the method developed to calculate left ventricular volume at a given point in the cardiac cycle required the left ventricular endocardial long-axis dimension to be measured at only one point in the cardiac cycle. METHODS. Studies were performed in 13 normal dogs, 8 normal puppies, 9 normal pigs, 12 dogs with aortic stenosis, 13 dogs with acute mitral regurgitation, 12 dogs with chronic mitral regurgitation, 7 dogs that had undergone mitral valve replacement and 6 pigs that had had chronic supraventricular tachycardia. Animals with aortic stenosis developed left ventricular pressure overload hypertrophy with a 60% increase in left ventricular mass; chronic mitral regurgitation caused left ventricular volume overload hypertrophy with a 46% increase in left ventricular volume; supraventricular tachycardia caused a dilated cardiomyopathy with a 55% decrease in left ventricular ejection fraction. RESULTS. The left ventricular epicardial long-axis/short-axis dimension ratio remained constant throughout the cardiac cycle in each animal group. End-diastolic and end-systolic volumes calculated with the simplified echocardiographic method correlated closely with angiographically measured volumes; for end-diastolic volume, echocardiographic end-diastolic volume = 1.0 (angiographic end-diastolic volume) -1.8 ml, r = 0.96; for end-systolic volume, echocardiographic end-systolic volume = 0.98 (angiographic end-systolic volume) -0.7 ml, r = 0.95. CONCLUSIONS. Thus the left ventricular epicardial long-axis/short-axis dimension ratio was constant throughout the cardiac cycle in a variety of animal species and age groups and in the presence of cardiac diseases that significantly altered left ventricular geometry and function. The simplified echocardiographic method examined provided an accurate determination of left ventricular volumes.     

Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data.

AIMS: Determination of left ventricular (LV) volumes and ejection fraction (EF) from two-dimensional echocardiographic (2DE) images is subjective, time-consuming, and relatively inaccurate because of foreshortened views and the use of geometric assumptions. Our aims were (1) to validate a new method for rapid, online measurement of LV volumes from real-time three-dimensional echocardiographic (RT3DE) data using cardiac magnetic resonance (CMR) as the reference and (2) to compare its accuracy and reproducibility with standard 2DE measurements. METHODS AND RESULTS: CMR, 2DE, and RT3DE datasets were obtained in 50 patients. End-systolic and end-diastolic volumes (ESV and EDV) were calculated from the 2DE images using biplane method of disks. ES and ED RT3DE datasets were analysed using prototype software designed to automatically detect the endocardial surface using a deformable shell model and calculate ESV and EDV from voxel counts. 2DE and RT3DE-derived volumes were compared with CMR (linear regression, Bland-Altman analysis). In most patients, analysis of RT3DE data required <2 min per patient. RT3DE measurements correlated highly with CMR (r: 0.96, 0.97, and 0.93 for EDV, ESV, and EF, respectively) with small biases (-14 mL, -6.5 mL, -1%) and narrow limits of agreement (SD: 17 mL, 16 mL, 6.4%). 2DE measurements correlated less well with CMR (r: 0.89, 0.92, 0.86) with greater biases (-23 mL, -15 mL, 1%) and wider limits of agreement (SD: 29 mL, 24 mL, 9.5%). RT3DE resulted in lower intra-observer (EDV: 7.9 vs. 23%; ESV: 7.6 vs. 26%) and inter-observer variability (EDV: 11 vs. 26%; ESV: 13 vs. 31%). CONCLUSION: Semi-automated detection of the LV endocardial surface from RT3DE data is suitable for clinical use because it allows rapid, accurate, and reproducible measurements of LV volumes, superior to conventional 2DE methods.     

Freehand three-dimensional echocardiography with rotational scanning for measurements of left ventricular volume and ejection fraction in patients with coronary artery disease

BACKGROUND: Measurement of left ventricular (LV) volumes and ejection fraction (EF) is important in managing patients with coronary artery disease (CAD). Introduction of free-hand three-dimensional echocardiography (3DE) system which is equipped with small magnetic tracking system and average rotational geometry for LV volumes may provide easy and accurate quantification of LV systolic function in CAD patients. PURPOSE: To evaluate the feasibility and accuracy of LV volumes and EF measurement by free-hand 3DE with rotational geometry in patients with CAD. METHODS AND RESULTS: The study subjects consisted of consecutive 25 patients with CAD who were scheduled for quantitative gated single-photon emission computed tomography (QGS). LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF were determined by conventional two-dimensional echocardiography (2DE), 3DE, and QGS. Three-dimensional echocardiography data acquisition and analysis were possible in 22 of 25 subjects (feasibility 88%). In this 3DE system, image acquisition time was 2 minutes, and 5 minutes were needed for off-line analysis of LV volumes and EF. Correlations and the limits of agreement between 3DE and QGS (r = 0.97, 0.0 +/- 9.1 ml for EDV, r = 0.99, 0.0 +/- 5.0 ml for ESV, and r = 0.97, 0.5 +/- 3.3% for EF, respectively) were superior to those between 2DE and QGS (r = 0.85, 12.6 +/- 26.8 ml for EDV, r = 0.85, 9.7 +/- 26.1 ml for ESV, and r = 0.90, -1.3 +/- 6.9% for EF, respectively). Inter- and intra-observer variabilities of 3DE were smaller than that of 2DE (5% vs 10%, 5% vs 10% for EDV, 6% vs 13%, 5% vs 9% for ESV, and 4% vs 11%, 4% vs 6% for EF, respectively). CONCLUSION: Three-dimensional echocardiography using magnetic tracking system and average rotational geometry offered a feasible and accurate method for quantification of LV volumes and EF in patients with CAD.     

Relation of left ventricular dilation during acute myocardial infarction to systolic performance, diastolic dysfunction, infarct size and location

The quantification of left ventricular (LV) volumes and assessment of their relation to systolic and diastolic dysfunction, infarct size and anatomic location were performed in 54 patients with a first acute myocardial infarction (AMI). Blood pool radionuclide angiography was used to assess LV end-diastolic, end-systolic, and stroke volume indexes, ejection fraction and peak diastolic filling rate. Infarct size was estimated from plasma MB creatine kinase activity. Substantial LV dilation occurred within the initial 24 hours of AMI. The peak diastolic filling rate was low, even in those patients with a normal ejection fraction. In comparison with inferior AMI (n = 25), patients with anterior AMI (n = 29) had a larger end-diastolic volume index (105 +/- 8 vs 81 +/- 4 ml/m2, p less than 0.01) and end-systolic volume index (64 +/- 7 vs 37 +/- 4 ml/m2, p less than 0.001), but similar stroke volume index (41 +/- 3 vs 43 +/- 2 ml/m2, difference not significant). No significant relation was noted between infarct size estimated by MB creatine kinase and any volumetric index. On repeat study (day 10 after AMI), end-diastolic and end-systolic volume indexes increased further (p less than 0.05 vs day 1) but ejection fraction and peak diastolic filling rate were unchanged. It was concluded that: (1) LV dilation occurs within hours of AMI in both inferior and anterior AMI, but is more marked in the latter; (2) significant LV diastolic dysfunction is the rule, even in patients with preserved LV systolic function; and (3) LV dilation is an early compensatory mechanism that maintains normal stroke volume, even in patients with severely reduced LV function.     

Comparison between direct volumetric and speckle tracking methodologies for left ventricular and left atrial chamber quantification by three-dimensional echocardiography

In an era of rapidly expanding and evolving 3-dimensional echocardiographic (3DE) technology, 1 of the issues facing the 3DE quantification of chamber volumes and function is that different software vendors use different methodologies and algorithms. The aim of this study was to evaluate the comparability and reproducibility of 3DE direct volumetric and speckle-tracking methods for left ventricular (LV) and left atrial (LA) chamber quantification. A total of 120 subjects (mean age 53 ± 17 years, 65% men), including 88 unselected patients and 32 healthy volunteers, underwent 3DE acquisitions and analysis using direct volumetric and speckle-tracking methods successively. Measurements of LV and LA volumes and LV function were compared between the 2 3DE methods. Additionally, intraobserver and interobserver reproducibility was assessed in 40 randomly selected patients. Measurements of LV end-diastolic volume, end-systolic volume, and ejection fraction by 3DE direct volumetric and 3DE speckle-tracking methods were comparable, with good correlations (r = 0.98, r = 0.98, and r = 0.87, respectively), small biases, and narrow limits of agreement (-1 ± 8 ml, -1 ± 8 ml, and 0 ± 6%, respectively). For measurements of LA end-systolic volume and end-diastolic volume, similar correlations (r = 0.96 for both), small biases, and narrow limits of agreement (-2 ± 6 and -1 ± 5 ml, respectively) were found between the 2 methods. Intraobserver and interobserver reproducibility for LV and LA quantification were comparable for the 2 methods. In conclusion, 3DE direct volumetric and speckle-tracking methods give comparable and reproducible quantification of LV and LA volumes and function, making interchangeable application a viable option in daily clinical practice.     

Normal values of real-time 3-dimensional echocardiographic parameters in a healthy Japanese population: the JAMP-3D Study

BACKGROUND: The recently developed real-time 3-dimensional echocardiography (RT3DE) is a promising imaging method to quantify cardiac chamber volumes and their functions in clinical practice. However, normal reference values of RT3DE parameters have not been fully investigated in a large, healthy Japanese population. Methods and Results: This study consisted of 410 healthy subjects aged from 20 to 69 years who had a RT3DE at one of the 23 collaborating institutions. All subjects had no history of cardiac disease and no risk factors. The mean values in men and women were as follows: 50 ± 12 ml/m(2) and 46 ± 9 ml/m(2) for left ventricular (LV) end-diastolic volume index, 19 ± 5 ml/m(2) and 17 ± 4 ml/m(2) for end-systolic volume index, 61 ± 4% and 63 ± 4% for ejection fraction, 64 ± 1 2 g/m(2) and 56 ± 11 g/m(2) for mass index, 23 ± 6 ml/m(2) and 24 ± 6 ml/m(2) for left atrial (LA) maximum volume index, 10 ± 3 ml/m(2) and 10 ± 3 ml/m(2) for minimum volume index, and 58 ± 6% and 58 ± 6% for percent volume change. LV sizes decreased with age, whereas LV mass index did not change. LA sizes slightly increased with age. Conclusions: This multicenter investigation determined normal reference values for LV and LA sizes, and their functional parameters on RT3DE in a large, healthy Japanese population. The results of the present study support the use of RT3DE for the diagnosis and management of cardiovascular disease.     

New generation 3-dimensional echocardiography for left ventricular volumetric and functional measurements: comparison with cardiac magnetic resonance.

AIMS: Non-invasive assessment of left ventricular (LV) structure and function is important in the evaluation of cardiac patients. This study was designed to test the accuracy and reproducibility of new generation 3-dimensional echocardiography (3DE) in measuring volumetric and functional LV indices as compared with current "gold standard" of non-invasive cardiac imaging, cardiac magnetic resonance (CMR). METHODS AND RESULTS: Sixty-four subjects with good acoustic windows, including 40 cardiac patients with LV ejection fraction (EF)<45%, 14 patients with EF>45% and 10 normal volunteers underwent 3DE using a commercially available Philips Sonos 7500 scanner equipped with a matrix phase-array x4 xMATRIX transducer, and CMR on a 1.5 T Signa CV/i scanner (GE Medical Systems). Volumetric assessment was performed with analytical 4D-LV-Analysis software (TomTec) for 3DE and MRI-Mass software (Medis) for CMR. We found no significant differences in LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF with excellent correlations between the indices measured using 3DE and CMR (r=0.97, r=0.98, and r=0.94, respectively). Bland-Altman analysis showed bias of 7 ml for EDV, 3 ml for ESV and -1% for EF with 3DE with corresponding limits of agreement (2SD) of 28 ml, 22 ml and 10%, respectively. Intraobserver and interobserver variabilities were for EDV: 3% and 4% (3DE) vs 2% and 2% (CMR), for ESV: 3% and 6% (3DE) vs 2% and 3% (CMR), and for EF: 4% and 4% (3DE) vs 2% and 4% (CMR), respectively. CONCLUSION: New generation 3DE provides accurate and reproducible quantification of LV volumetric and functional data in subjects with good acoustic windows as compared with CMR.     

A meta-analysis and investigation for the source of bias of left ventricular volumes and function by three-dimensional echocardiography in comparison with magnetic resonance imaging

Determining accurate left ventricular (LV) function is clinically important. Three-dimensional echocardiography (3DE) achieves better estimation than 2-dimensional echocardiography. However, underestimation of LV volumes has often been reported without a systematic attempt to synthesize these data. This meta-analysis aimed to assess the bias of 3DE in evaluating LV volumes and ejection fraction (EF) and to investigate factors affecting that bias. Studies that compared LV volumes and/or EF between 3DE and magnetic resonance imaging were eligible. Meta-analysis of 95 studies including 3,055 subjects revealed significant underestimation of LV end-systolic volume (-4.7 ml, p <0.0001) and end-diastolic volume (-9.9 ml, p <0.0001), whereas measurement for EF revealed excellent accuracy (-0.13%, p = 0.41). Meta-regression analysis for factors of systematic bias in volumetry revealed that female gender and existence of cardiac disease were associated with more underestimation, whereas use of semiautomatic tracking and matrix-array transducers counteracted the underestimation. In conclusion, by meta-analysis synthesizing many small studies, we found underestimation of LV volumes and factors affecting the systematic bias by 3DE. These data provide a more detailed basis for analyzing and improving the accuracy of 3DE, an indispensable step toward further clinical application in LV assessment.