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.     

Automated method for left ventricular volume measurement by cineventriculography with minimal doses of contrast medium

Cineventriculography is of considerable value in the dimensional analysis of the left ventricular cavity, but conventional methods necessitate injection of large amounts of contrast medium. In this study, small dose left ventriculography, using only 5 ml of dye, was performed in order to minimize the untoward effects of contrast medium. A computer-aided image processing system was also developed to enhance the contrast of the ventricular image by subtracting the reference image to eliminate irrelevant background. The boundary of the left ventricular cavity was automatically determined to calculate the instantaneous volume change throughout the cardiac cycle. With use of this small dose of dye, the elevation of left ventricular end-diastolic pressure that consistently occurred 1 to 3 minutes after injection of conventional large doses could be avoided. (End-diastolic pressure at 1 minute after dye injection averaged 11.8 ± 4.9 [mean ± standard deviation] for small dose and 19.1 ± 6.1 mm Hg for large dose injection.) Values for end-diastolic volume, end-systolic volume and ejection fraction calculated from the two consecutive small and large dose left ventriculograms in 16 patients were similar.Thus, minimal doses of contrast medium permit accurate measurement of left ventricular dimension and function without significant hemodynamic derangement. The optimal projection for regional wall motion analysis can easily be selected by this method with repeated exposure at various degrees of obliquity. With this technique, even noninvasive measurement of left ventricular volume can be provided by intravenous injection of small doses of contrast agent.     

Real-time three-dimensional echocardiography for measurement of left ventricular volumes

Left ventricular (LV) volumes are important prognostic indexes in patients with heart disease. Although several methods can evaluate LV volumes, most have important intrinsic limitations. Real-time 3-dimensional echocardiography (RT3D echo) is a novel technique capable of instantaneous acquisition of volumetric images. The purpose of this study was to validate LV volume calculations with RT3D echo and to determine their usefulness in cardiac patients. To this end, 4 normal subjects and 21 cardiac patients underwent magnetic resonance imaging (MRI) and RT3D echo on the same day. A strong correlation was found between LV volumes calculated with MRI and with RT3D echo (r = 0.91; y = 20.1 + 0.71x; SEE 28 ml). LV volumes obtained with MRI were greater than those obtained with RT3D echo (126 ± 83 vs 110 ± 65 ml; p = 0.002), probably due to the fact that heart rate during MRI acquisition was lower than that during RT3D echo examination (62 ± 11 vs 79 ± 16 beats/min; p = 0.0001). Analysis of intra- and interobserver variability showed strong indexes of agreement in the measurement of LV volumes with RT3D echo. Thus, LV volume measurements with RT3D echo are accurate and reproducible. This technique expands the use of ultrasound for the noninvasive evaluation of cardiac patients and provides a new tool for the investigational study of cardiovascular disease.     

Comparison of two- and three-dimensional transthoracic echocardiography in the assessment of trabeculations and trabecular mass in left ventricular noncompaction

Twenty-one patients (mean age 47.5 years, 9 females) with left ventricular noncompaction (LVNC) diagnosed by both two-dimensional transthoracic echocardiography (2DTTE) and live/real time three-dimensional transthoracic echocardiography (3DTTE) were included in the study. Left ventricular (LV) mass was calculated with epicardial and endocardial border tracings first including the LV trabeculations and then excluding them. LV trabecular mass was then derived as the difference between the two measurements. This was done by 2DTTE using the modified biplane Simpson's method and by live/real time 3DTTE using the Tom Tec imaging system. The number of trabeculations arising from each segment of LV walls as well as the segmental distribution of trabeculations were also assessed by both 2DTTE and 3DTTE. The calculated LV trabecular mass by 3DTTE (mean 11.8 +/- 5.5 g) was significantly greater than 2DTTE (mean 7.3 +/- 4.3 g, P = 0.005). The total number of trabeculations assessed by 3DTTE (mean 11.2 +/- 3.3) was also significantly greater than 2DTTE (mean 3.76 +/- 1.2, P < 0.0001). The values for inter- and intraobserver variability were lower for 3DTTE than 2DTTE. In conclusion, both LV trabecular mass as well as the total number of trabeculations in patients with LVNC were significantly underestimated by 2DTTE as compared to 3DTTE.     

In vivo and in vitro evaluation of left ventricular thrombi by two-dimensional echocardiography. Comparison with cineventriculography

The purpose of this study was to assess the capability of two-dimensional echocardiography to identify left ventricular thrombi as compared to standard single plane cineventriculography in 284 patients, who underwent both procedures within 24 hours for diagnostic purposes. In order to obtain informations about the degree of thrombus organization and diagnostic accuracy of the echocardiographic technique, two-dimensional echocardiographic examinations were also performed in 31 thrombi from 16 autopsy specimens. In 249 cases the results were negative and in 14 cases positive by both techniques. Seven cases were positive by cineventriculography but negative by 2D-echocardiography. In seven cases the findings were equivocal by two-dimensional echocardiography; three of them were negative, two positive, and two equivocal by cineventriculography. In two cases the results were negative by two-dimensional echocardiography but equivocal by cineventriculography. Finally five cases were diagnosed to have a thrombus but two-dimensional echocardiography but not by cineventriculography. In two patients, positive by two-dimensional echocardiography, who were on anticoagulant therapy, follow-up studies showed the disappearance of left ventricular thrombi. In all of them the thrombi showed tissue characteristics similar to those of fresh thrombi examined in vitro. Two-dimensional echocardiography seems to be more reliable than cineventriculography for assessing the presence, extension, number, and morphology of left ventricular thrombi. In vitro studies suggest that two-dimensional echocardiography cannot visualize small thrombi, that fibrotic areas may simulate a thrombus and that in some cases under or overestimation is possible.     

Left ventricular volume measurement with echocardiography: a comparison of left ventricular opacification, three-dimensional echocardiography, or both with magnetic resonance imaging

Aims: Both contrast enhanced (CE) two-dimensional echocardiography(2DE) and three-dimensional echocardiography (3DE) have beenproposed as techniques to improve the accuracy of left ventricular(LV) volume measurements. We sought to examine the accuracyof non-contrast (NC) and CE-2DE and 3DE for calculation of LVvolumes and ejection fraction (EF), relative to cardiac magneticresonance imaging (MRI). Methods and results: We studied 50 patients (46 men, age 63 ± 10 year) withpast myocardial infarction who underwent echocardiographic assessmentof LV volume and function. All patients sequentially underwentNC-2DE followed by NC-3DE. CE-2DE and CE-3DE were acquired duringcontrast infusion. Resting echocardiographic image quality wasevaluated on the basis of NC-2DE. The mean LV end-diastolicvolume (LVEDV) of the group by MRI was 207 ± 79 mL andwas underestimated by 2DE (125 ± 54 mL, P = 0.005), andless by CE-2DE (172 ± 58 mL, P = 0.02) or 3DE (177 ±64 mL, P = 0.08), but EDV was comparable by CE-3DE (196 ±69 mL, P = 0.16). Limits of agreement with MRI were similarfor NC-3DE and CE-2DE, with the best results for CE-3D. Resultswere similar for calculation of LVESV. Patients were categorizedinto groups of EF (35, 35–50, >50%) by MRI. NC-2DEdemonstrated a 68% agreement (kappa 0.45, P = 0.001), CE-2DEa 62% agreement (kappa 0.20, P = 136), NC-3DE a 74% agreement(kappa 0.39, P = 0.005) and CE-3DE an 80% agreement (kappa 0.56,P < 0.001). Conclusion: CE-2DE is analogous to NC-3DE in accurate categorization ofLV function. However, CE-3DE is feasible and superior to otherNC- and CE-techniques in patients with previous infarction.     

Two-dimensional color Doppler echocardiography for left ventricular stroke volume assessment: a comparison study with three-dimensional echocardiography

Aim: Whether measurement of left ventricular outflow tract diameter (LVOTd) using color Doppler (CD) in order to more accurately define LVOTd is more accurate for determination of stroke volume (SV) than gray scale and compare it with direct measurement of LVOT area (a) using three‐dimensional echocardiography (3DE) for SV determination. Methods and Results: Twenty‐one volunteers were examined. LVOTa was calculated by two‐dimensional echocardiography (2DE) using the following formula: π× (d/2)², d = LVOT diameter by gray scale and CD, respectively. Planimetry of LVOTa was performed in parasternal long axis using 3DE. Eccentricity Index was calculated using the lateral and anterior‐posterior LVOTd. SV was obtained by four different methods: (1) 2D gray scale, (2) 2D color, (3) LVOTa × LVOT velocity time integral, and (4) SV by Simpson's biplane method. Gray scale LVOTd was significantly smaller compared to LVOTd obtained with CD (P < 0.05). Significant differences occurred between LVOTa gray scale and CD (3.29 ± 0.74 cm² vs 3.67 ± 0.70 cm², P < 0.05) and between LVOTa calculated by gray scale in comparison to 3DE planimetry; (3.29 ± 0.74 cm² vs 3.61 ± 0.89 cm², P = 0.011). Half of the subjects had at least 17% difference between the lateral and anterior‐posterior LVOTd. There were significant differences between SV by 2D gray scale and 2D CD (82.8 ± 17.1 mL vs 92.4 ± 16.8 mL, P < 0.05) and between 2D gray scale and 3DE planimetry (82.8 ± 17.1 mL vs 90.7 ± 19.8 mL, P = 0.025). Conclusion: Our study demonstrates LVOT being frequently elliptical. SV and LVOTa were found to be similar when comparing 2DE CD and 3DE planimetry and showed higher values in comparison to 2DE gray scale, which suggests 2DE CD to be an alternative approach for SV assessment.     

Comparison of accurate measurement of left ventricular mass in patients with hypertrophied hearts by real-time three-dimensional echocardiography versus magnetic resonance imaging

To evaluate whether left ventricular (LV) mass assessed by a new real-time, 3-dimensional echocardiographic (RT-3DE) system corresponds to cardiac magnetic resonance imaging (MRI) in patients with LV hypertrophy, RT-3DE and 2-dimensional echocardiography (2DE) were performed to calculate LV mass in 21 patients (mean age 54 +/- 15 years) who underwent MRI for the evaluation of LV hypertrophy. In 20 of 21 patients, adequate 3-dimensional data for LV mass analysis were obtained, and regression analysis showed that LV mass by RT-3DE correlated with that determined by MRI (r = 0.95, y = 28.9 + 0.85x) better than with that determined by 2DE (r = 0.70, y = 43.6 + 0.81x). RT-3DE allows the accurate measurement of LV mass in patients with hypertrophied hearts.     

实时三维超声心动图评价高血压前期左心房功能的研究

目的探讨实时三维超声心动图（RT3DE）评价高血压病前期人群左心房功能的价值。方法纳入2012年6月~2012年12月北京军区总医院高血压前期患者[收缩压120~139 mmHg和（或）舒张压80~90 mmHg]80例,纳入同期血压＜120/80 mmHg者40例作为对照组,应用二维超声心动图测量左心房、室内径、室间隔厚度（IVST）、左室后壁厚度,及左心室舒张功能指标,如舒张早期峰值速度（E）、收缩期峰值速度（A）、二尖瓣环舒张早期运动速度（E’）、收缩期运动速度（A’）,计算E/A。应用RT3DE测量左心房最大容积（LAVmax）、左心房最小容积（LAVmin）及左心房收缩前容积（LAVpre）,计算左心房每搏射血量（LASV）、左心房排空分数（LAEF%）、左心房被动排空分数（LAp%）及左心房主动排空分数（LAa%）,并对两组结果进行对比分析。结果①二维超声心动图结果：与对照组相比,高血压前期组IVST更厚[（9.71±0.81）mm vs.（9.04±1.08）mm,P＜0.05],余指标无统计学差异（P均＞0.05）;②RT3DE结果：与对照组比较,高血压前期组LAVmax、LAVpre、LAEF%、LASV及LAa%更高[分别为（35.46±4.27）ml vs.（31.56±3.34）ml,（20.58±3.72）ml vs.（17.84±3.32）ml,（55.60±8.23）%vs.（50.47±7.27）%,（20.34±5.74）ml vs.（16.79±5.12）ml,（39.48±10.48）%vs.（31.57±10.26）%,P均＜0.05],LAp%更低[（43.69±10.32）%vs.（47.26±10.67）%,P均＜0.05]。结论RT3DE较二维超声心动图更能早期发现高血压前期人群左心房容积和功能改变。     

Meta-analysis of accuracy of left ventricular mass measurement by three-dimensional echocardiography

Left ventricular (LV) hypertrophy is a fundamental prognostic factor in a variety of cardiac diseases. Three-dimensional echocardiography (3DE) has achieved better estimation of LV mass than 2-dimensional echocardiography. However, significant underestimation has often been reported, and no previous study has synthesized these data. The aim of this meta-analysis was to investigate if there has been improvement in the accuracy in LV mass measurement by 3DE over time. Studies comparing LV mass between 3DE and magnetic resonance imaging were eligible. A cumulative meta-analysis was performed to investigate improvement in accuracy, followed by subgroup and meta-regression analysis to reveal factors affecting the bias. A total of 25 studies including 671 comparisons were analyzed. Studies published in or before 2004 showed high heterogeneity (I(2) = 69%) and significant underestimation of LV mass by 3DE (-5.7 g, 95% confidence interval -11.3 to -0.2, p = 0.04). Studies published from 2005 to 2007 were still heterogenous (I(2) = 60%) but showed less systematic bias (-0.5 g, 95% confidence interval -2.5 to 1.5, p = 0.63). In contrast, studies published in or after 2008 were highly homogenous (I(2) = 3%) and showed excellent accuracy (-0.1 g, 95% confidence interval -2.2 to 1.9, p = 0.90). Investigation of factors affecting the bias revealed that evaluation of cardiac patients compared to healthy volunteers led to larger bias (p <0.05). In conclusion, this meta-analysis elucidates the underestimation of LV mass by 3DE, its improvement over the past decade, and factors affecting the bias. These data provide a more detailed basis for improving the accuracy of 3DE, an indispensable step toward further clinical application.     

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.     

Comparison of two-dimensional echocardiography, angiocardioscintigraphy and cineventriculography in the study of left ventricular wall motion in ischemic cardiopathy

Thirty-two patients with non acute myocardial infarction (inferior in twenty, anterior in ten, anterior and inferior in two) were studied with contrast left ventriculography, two-dimensional echocardiography and radionuclide angiography to assess left ventricular wall motion. We adopted the CASS criteria for the standard left ventriculography, and the Mayo Clinic classification for the echocardiographic study. Radionuclide angiography studies were obtained in left anterior oblique view; the images were evaluated with the use of Walsh-Hadamard transform; the left ventricle was divided in basal and apical septal, apical, posterolateral, posterobasal and two central segments. We tried to correlate the findings of the three techniques both for single segments and larger regions made of contiguous segments. Left ventricular angiography and two-dimensional echocardiography showed a fair concordance for both anterobasal and posterolateral left ventricular wall, whereas for the septal, apical and posterolateral regions contrast and radionuclide angiography had the best correlation. Compared to left ventricular angiography two-dimensional echocardiography shows better sensitivity than radionuclide angiography; the latter is more specific in defining left ventricular wall motion. The two non invasive techniques are therefore helpful in the evaluation of wall motion and their role is complementary.     

M-mode echocardiography overestimates left ventricular mass in patients with normal left ventricular shape: a comparative study using three-dimensional echocardiography.

AIMS: We sought to evaluate whether left ventricular (LV) mass (M) determined by M-mode echocardiography is overestimated compared with LVM calculated by three-dimensional (3D) echocardiography (E) in patients with normal LV shape. METHODS AND RESULTS: A total of 112 studies in 56 patients (60+/-13 years) with hypertension (n=25) or aortic stenosis (n=31) and 30 control subjects (57+/-14 years) evaluated for cardiac sources of embolism were analyzed. LVM by M-mode and 3DE was highly correlated (r=0.85; p<0.001). However, there were broad limits of agreement (-58 to 110 g) demonstrating large variability between the methods. M-mode overestimated 3DE LVM by a mean of 15+/-24% (p<0.001) with overestimation in controls and the different patient groups. Variability was unrelated to increasing quartiles of LVM values. Using technique-specific partition values for normal LVM, the agreement between M-mode and 3DE for the detection of LV hypertrophy was 83% (Kappa=0.59; p<0.001). CONCLUSION: Although M-mode and 3DE correlate well for the calculation of LVM, there is a systematic difference between the two techniques leading to overestimation of LVM by the 1D technique. Thus, previously published cutoff values for normal LVM derived from M-mode may not apply for 3DE. However, the use of technique-specific partition values allows stratification of patients for the presence of LV hypertrophy with reasonable agreement.     

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.     

New digital measurement methods for left ventricular volume using real-time three-dimensional echocardiography: comparison with electromagnetic flow method and magnetic resonance imaging.

AIM: The aim of this study was to investigate the feasibility and accuracy of using symmetrically rotated apical long axis planes for the determination of left ventricular (LV) volumes with real-time three-dimensional echocardiography (3DE). METHODS AND RESULTS: Real-time 3DE was performed in six sheep during 24 haemodynamic conditions with electromagnetic flow measurements (EM), and in 29 patients with magnetic resonance imaging measurements (MRI). LV volumes were calculated by Simpson's rule with five 3DE methods (i.e. apical biplane, four-plane, six-plane, nine-plane (in which the angle between each long axis plane was 90 degrees, 45 degrees, 30 degrees or 20 degrees, respectively) and standard short axis views (SAX)). Real-time 3DE correlated well with EM for LV stroke volumes in animals (r=0.68-0.95) and with MRI for absolute volumes in patients (r-values=0.93-0.98). However, agreement between MRI and apical nine-plane, six-plane, and SAX methods in patients was better than those with apical four-plane and bi-plane methods (mean difference = -15, -18, -13, vs. -31 and -48 ml for end-diastolic volume, respectively, P<0.05). CONCLUSION: Apically rotated measurement methods of real-time 3DE correlated well with reference standards for calculating LV volumes. Balancing accuracy and required time for these LV volume measurements, the apical six-plane method is recommended for clinical use.