Sources of variation and bias in assessing left ventricular volumes and dyssynchrony using three-dimensional echocardiography

Study aim To explore various sources of variability in the measurement of LV volumes and dyssynchrony by 3D echocardiography (3DE). Methods We studied 100 patients (58?±?18?years, 51 men) to assess the impact of: (1) manual editing; (2) 3D data set temporal resolution; (3) LV 16- or 17-segmentation model; (4) software sensitivity for automated endocardial surface detection; and (5) image quality, on the measurement of LV end-diastolic (EDV) and end-systolic (ESV) volumes, sphericity indices (EDSI, ESSI), ejection fraction (EF) and dyssynchrony (SDI). Two- and 4-beat LV full-volume data sets were analyzed and compared. Cardiac magnetic resonance (CMR) was used as reference in 26 patients. Results Manual editing of endocardial surface improved the agreement of LV volumes with CMR, but increased SDI (SDI17: 5.6?±?0.5% vs. 4.3?±?0.3%; P?相似文献   

Quantification of left ventricular volume and global function using a fast automated segmentation tool: validation in a clinical setting

Real-time 3D echocardiography (RT3DE) has already been shown to be an accurate tool for left ventricular (LV) volume assessment. However, LV border detection in RT3DE remains a time-consuming task jeopardizing the application of this modality in routine practice. We have recently developed a 3D automated segmentation framework (BEAS) able to capture the LV morphology in real-time. The goal of this study was to assess the accuracy of this approach in extracting volumetric parameters in a clinical setting. 24 RT3DE exams were acquired in a group of healthy volunteers (# = 5) and diseased patients (# = 19), with LV volume/function within a range typically measured in a clinical setting. End-diastolic and end-systolic volumes (EDV, ESV) were manually contoured by 3 expert sonographers from which the stroke volume and ejection fraction (SV, EF) were calculated. The values extracted with BEAS were compared to the average of the 3 experts measurements using correlation and Bland–Altman statistics. Linear regression analysis showed a strong correlation between the automated algorithm and the reference values (R = 0.963, 0.947, 0.944 and 0.853 for EDV, ESV, SV and EF respectively). Bland–Altman analysis revealed a bias (limits of agreement) of 2.59 (?25.39, 30.57) ml, ?2.11 (?24.91, 20.69) ml, 4.70 (12.93, 22.34) ml and 3.45 (?8.96, 15.87) %, for EDV, ESV, SV and EF respectively. Total analysis time using BEAS was 30.7 ± 7.5 s. BEAS allows for a fast and accurate quantification of 3D cardiac volumes and global function with minimal user input. It may therefore contribute to the integration of 3D echocardiography in routine clinical practice.     

实时三维超声心动图定量冠心病、扩张型心肌病心房和心室容积及功能的研究

目的应用实时三维超声心动图(RT-3DE)定量评价冠心病、扩张型心肌病患者左心室、左心房、右心室和右心房容积及收缩功能。方法在24例正常人、16例扩张性心肌病和27例心肌梗死患者中,应用实时三维超声心动图获取各房室全容积三维图像,分别应用2、4、8平面方法测量各房室收缩末期容积(ESV)、舒张末期容积(EDV)和射血分数(EF),并与二维超声心动图(2DE)Simpson法和声学定量(AQ)技术测值比较。结果在扩张性心肌病和心肌梗死患者中,2DE、AQ技术和RT-3DE2平面法测量的左、右心房和左、右心室ESV、EDV明显低于RT-3DE4平面法、8平面法测值(P<0.05);各种方法检测的EF值差异无统计学意义(P>0.05)。2DE、AQ技术和RT-3DE检测结果均显示扩张性心肌病、心肌梗死患者各房室ESV、EDV均明显大于正常组(P<0.05),EF明显低于正常组(P<0.05)。结论应用实时三维超声心动图能显示心腔立体结构,测量各心腔容积,评价心脏功能。     

MRI、SPECT和二维超声心动图评价原发性扩张型心肌病心功能的比较影像学研究

目的应用MRI与二维超声心动图（2DE）、99Tcm-MIBISPECT对原发扩张型心肌病（IDCM）定量评价左室功能和容积;比较三种影像学方法评价心功能与NYHA分级的相关性。方法使用MRI与2DE、SPECT对42例IDCM患者分别进行左室容积和功能测量。NYHAⅠ～Ⅱ级11例,Ⅲ级16例,Ⅳ级15例。MRI采用Argus软件MassAnalysis功能进行测量和计算,2DE采用Simspon法测算,SPECT采用QGS软件处理。结果三种检查方法对EDV、ESV、EF的测值相关性好,MRI与SPECT所测指标的r值大于0.9;MRI与2DE所测指标r值为0.699～0.878。MRI与2DE、SPECT比较左室容积差异均有统计学意义,然而2DE和SPECT均低估左室容积;与MRI比较,2DE低估EF值,而SPECT没有低估。MRI与NYHA心功分级比较：心功能Ⅲ、Ⅳ级与心功能Ⅰ～Ⅱ级比较,ESV、SV、EF、PER、PFR、EDD、ESD的差异有统计学意义;2DE与NYHA心功分级比较：心功能Ⅲ、Ⅳ级与心功能Ⅰ～Ⅱ级比较,ESV和EF的差异有统计学意义;Ⅳ级与心功能Ⅰ～Ⅱ级比较,EDD、ESD差异有统计学意义;SPECT与NYHA心功分级比较：心功能Ⅲ、Ⅳ级与心功能Ⅰ～Ⅱ级比较,ESV和EF差异有统计学意义。结论 MRI与SPECT比较心功能指标之间相关性良好,MRI较2DE提供更多的左室功能和容积参数,而2DE低估左室容积;三种方法与NYHA心功能分级均有良好的相关性。     

Single-beat real-time three-dimensional echocardiographic automated contour detection for quantification of left ventricular volumes and systolic function

To assess the feasibility and accuracy in measuring left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) with Siemens single-beat real-time 3D transthoracic echocardiography. The LV volumes and EF were measured in 3D datasets acquired by six imaging modes (time-1-harmonic (T1H), time-1-fundamental, time-2-harmonic, time-2-fundamental, space-1-harmonic (S1H), and space-1-fundamental) in 41 patients using the automated contouring algorithm and compared with manually corrected 3DE QLAB measurements. The main determinates of the temporal and spatial resolutions of 3D datasets acquired were the fundamental and harmonic modes. Consequently, the S1H mode had the lowest volume rate and highest spatial resolution. Compared with the 3DE QLAB analysis, the S1H mode resulted in the best LV volumes and EF estimates in all patients (0 ± 10 % for EF, ?7 ± 44 ml for EDV, ?7 ± 39 ml for ESV) and in the 10 patients with correct LV contour tracking according to a visual assessment from the multiplanar reconstruction views in all six modes (0 ± 9 % for EF, ?3 ± 23 ml for EDV, ?2 ± 14 ml for ESV). The T1H mode was the best alternative. Overall 28 patients (68 %) could be analysed automatically and satisfyingly with the S1H and T1H modes: 0 ± 8 % (EF), 0 ± 27 ml (EDV) and ?1 ± 16 ml (ESV). The accuracy of the Siemens automated RT-3D algorithm in measuring LV volumes and EF is significantly influenced by the different imaging modes. The S1H mode may be the preferred 3D acquisition mode, supplemented by the T1H mode in enlarged LVs that do not fit in the S1H acquisition sector.     

Quantification of left ventricular volumes and ejection fraction using freehand transthoracic three-dimensional echocardiography: comparison with magnetic resonance imaging.

OBJECTIVES: Our aim was to validate 3-dimensional echocardiography (3DE) for assessment of left ventricular (LV) end-diastolic volume, end-systolic volume (ESV), stroke volume, and ejection fraction (EF) using the freehand-acquisition method. Furthermore, LV volumes by breath hold-versus free breathing-3DE acquisition were assessed and compared with magnetic resonance imaging (MRI). METHODS: From the apical position, a fan-like 3DE image was acquired during free breathing and another, thereafter, during breath hold. In 27 patients, 28 breath hold- and 24 free breathing-3DE images were acquired. A total of 17 patients underwent both MRI and 3DE. MRI contours were traced along the outer endocardial contour, including trabeculae, and along the inner endocardial contour, excluding trabeculae, from the LV volume. RESULTS: All 28 (100%) breath hold- and 86% of free breathing-3DE acquisitions could be analyzed. Intraobserver variation (percentual bias +/- 2 SD) of end-diastolic volume, ESV, stroke volume, and EF for breath-hold 3DE was, respectively, 0.3 +/- 10.2%, 0.3 +/- 14.6%, 0.1 +/- 18.4%, and -0.1 +/- 5.8%. For free-breathing 3DE, findings were similar. A significantly better interobserver variability, however, was observed for breath-hold 3DE for ESV and EF. Comparison of breath-hold 3DE with MRI inner contour showed for end-diastolic volume, ESV, stroke volume, and EF, a percentual bias (+/- 2 SD) of, respectively, -13.5 +/- 26.9%, -17.7 +/- 47.8%, -10.6 +/- 43.6%, and -1.8 +/- 11.6%. Compared with the MRI outer contour, a significantly greater difference was observed, except for EF. CONCLUSIONS: 3DE using the freehand method is fast and highly reproducible for (serial) LV volume and EF measurement, and, hence, ideally suited for clinical decision making and trials. Breath-hold 3DE is superior to free-breathing 3DE regarding image quality and reproducibility. Compared with MRI, 3DE underestimates LV volumes, but not EF, which is mainly explained by differences in endocardial contour tracing by MRI (outer contour) and 3DE (inner contour) of the trabecularized endocardium. Underestimation is reduced when breath-hold 3DE is compared with inner contour analysis of the MRI dataset.     

Rapid full volume data acquisition by real-time 3-dimensional echocardiography for assessment of left ventricular indexes in children: a validation study compared with magnetic resonance imaging.

OBJECTIVE: We sought to assess the feasibility, accuracy, and reproducibility of a rapid full volume acquisition strategy using real-time (RT) 3-dimensional (3D) echocardiography (3DE) for measurement of left ventricular (LV) volumes, mass, stroke volume (SV), and ejection fraction (EF) in children. METHODS: A total of 19 healthy children (mean 10.6 +/- 2.8 years, 11 male and 9 female) were prospectively enrolled in this study. RT 3DE was performed using an ultrasound system to acquire full volume 3D dataset from the apical window with electrocardiographic triggering in 8 s/dataset. The images were processed offline using software. The LV endocardial and epicardial borders were traced manually to derive LV end-systolic volume, end-diastolic volume, mass, SV, and EF. Magnetic resonance imaging (MRI) studies were performed on a 1.5-T scanner using a breath hold 2-dimensional cine-FIESTA (fast imaging employing steady-state acquisition) sequence. RESULTS: All RT 3DE and MRI data were acquired successfully for analysis. Measurements of LV end-systolic volume, end-diastolic volume, mass, SV, and EF by RT 3DE correlated well by Pearson regression ( r = 0.86-0.97, P < .001) and agreed well by Bland-Altman analysis with MRI. The interobserver and intraobserver variability of RT 3DE measurements were less than 5%. CONCLUSIONS: This prospective study demonstrated that RT 3DE measurements of LV end-systolic volume, end-diastolic volume, mass, SV, and EF in children using rapid full volume acquisition strategy are feasible, accurate, and reproducible and are comparable with MRI measurements.     

A real-time three-dimensional echocardiographic validation of an intracardiac electrogram-based method for optimizing cardiac resynchronization therapy

INTRODUCTION: Although optimization of atrioventricular and interventricular delays has been demonstrated to improve hemodynamics in patients with cardiac resynchronization therapy (CRT), the required time-consuming procedure discourages its use in clinical practice. Recently, a new method for CRT optimization based on the intracardiac electrogram (IEGM) detected by the implanted leads, has been developed. We evaluated the effectiveness of this method in improving left ventricular (LV) asynchrony and performance using real-time 3D echocardiography (RT3DE). METHODS AND RESULTS: Twenty patients with CRT were prospectively studied. RT3DE was performed before and after IEGM optimization. The standard deviation of the time to the regional LV minimum systolic volume (Tmsv) for all 16 segments (Tmsv 16-SD), six basal and six mid segments (Tmsv 12-SD), and the six basal segments (Tmsv 6-SD) were assessed as a asynchrony indexes. LV end-diastolic and end-systolic volumes (EDV, ESV), stroke volume (SV), ejection fraction (EF), myocardial performance index (MPI), ejection time (ET), and filling time (FT), corrected by R-R interval, were also evaluated. After IEGM optimization, as compared with baseline Tmsv 12-SD and Tmsv 16-SD decreased (P = 0.01, P< 0.001, respectively), EF and SV improved (P < 0.001, P = 0.01 respectively), FT/RR and ET/RR increased (P = 0.02 for both), and MPI improved (P < 0.001). Tmsv 6-SD, EDV and ESV did not change. CONCLUSION: A simple IEGM-based method of CRT optimization decreased LV dyssynchrony and improved systolic function.     

Comparison of left ventricular volumes and ejection fraction by monoplane cineventriculography, unenhanced echocardiography and cardiac magnetic resonance imaging

Right-anterior-oblique (RAO) monoplane cineventriculography is usually applied in cardiac catheter labs to assess the left ventricular (LV) function. However, it is uncertain whether this technique is reliable in clinical routine. Unenhanced two-dimensional echocardiography was reported to underestimate left ventricular volumes. The aim of this study was to compare these two conventional techniques with cardiac magnetic resonance imaging (MRI), the present gold standard for the determination of LV function, to evaluate whether the results from the conventional techniques are reliable and in accordance with each other. Seventy-two patients were retrospectively recruited and analysis of the three techniques was performed. Compared with MRI, RAO cineventriculography underestimated LV end-systolic volumes (ESV), and overestimated LV ejection fraction (EF); two-dimensional echocardiography underestimated LV end-diastolic volume (EDV) and EF. Correlation coefficients on EDV, ESV, and EF were 0.8806, 0.9201, and 0.8864 between echocardiography and MRI (P < 0.01, for all), followed by 0.7718, 0.8835, and 0.7785, between cineventriculography and MRI (P < 0.01, for all), and 0.7006, 0.7680, and 0.7644 between cineventriculography and echocardiography (P < 0.01, for all). Echocardiography and MRI showed the highest inter-technique correlation coefficients, and the narrowest Bland-Altman limits of agreement for EDV, ESV and EF. EDV, ESV and EF determined by RAO monoplane cineventriculography, unenhanced two-dimensional echocardiography and MRI were in high accordance with each other, with wide variances between the techniques. Although not interchangeable, RAO monoplane cineventriculography, unenhanced two-dimensional echocardiography, and cardiac MRI are reliable tools in clinical routine for the assessment of LV volumes and function.     

Assessment of left atrial volumes in sinus rhythm and atrial fibrillation using the biplane area-length method and cardiovascular magnetic resonance imaging with TrueFISP.

OBJECTIVES: To determine whether the biplane area-length method can be used for the evaluation of left atrial volumes and ejection fraction with cardiovascular magnetic resonance imaging (CMR) by TrueFISP in normal subjects and patients with atrial fibrillation. BACKGROUND: Atrial fibrillation is the most common arrhythmia in elderly patients. Left atrial size and volumes play an important role in predicting short and long-term success after cardioversion. METHODS: Fifteen healthy subjects (mean age 65.6+/-6.4 years) and 18 patients (mean age 67.2+/-8.8 years) with atrial fibrillation were examined by CMR (Magnetom, Siemens, Erlangen, Germany). Images were acquired by TrueFISP using the horizontal and vertical long-axis plane to measure left atrial end-diastolic and end-systolic areas and longitudinal dimensions. Volumes were determined with commercially available software. Left atrial end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) were determined by the biplane area-length method and compared to findings obtained by the standard short-axis method. Images were acquired and analyzed a second time in the patients with atrial fibrillation. RESULTS: There was no difference in age between men and women (p=0.147) and healthy subjects and patients (p=0.128) included in the study. EDV and ESV were significantly higher and SV and EF significantly lower in patients with atrial fibrillation than in healthy subjects (p < or = 0.009), regardless of the method used. The values obtained for EDV and ESV by the biplane area-length method were significantly higher in both healthy subjects (p<0.001) and patients with atrial fibrillation (p<0.001) than those obtained by the standard short-axis approach, whereas SV (p> or = 0.057) and EF (p> or = 0.118) did not differ significantly. In the second investigation in patients with atrial fibrillation, ESV, SV, and EF did not differ significantly between the two methods (p> or =0.481). Assessment of interobserver variability revealed good agreement in the findings of the two observers, both in normal sinus rhythm and atrial fibrillation (overall variability 0.8+/-6.5%). CONCLUSIONS: The biplane area-length method can be used in CMR images obtained by TrueFISP to assess left atrial volumes and ejection fraction in normal subjects and patients with varying cardiac cycle length, as in atrial fibrillation.     

实时三维超声心动图容积-时间曲线评价左心室舒张功能的初步研究

目的 利用实时三维超声心动图容积-时间曲线评价左室舒张功能正常及异常患者的曲线变化情况。方法以频谱组织多普勒二尖瓣环舒张早期速度〈二尖瓣环舒张晚期速度为左室舒张功能减低的诊断标准，取24例单纯左室舒张功能减低的患者（分为松弛延迟组及假性正常化组，各12例）和24例健康志愿者，进行实时三维超声心动图全容积采集，并进行容积-时间曲线分析，比较三组实时三维超声心动图参数：左室舒张末容积（EDV）、左室收缩末容积（ESV）、左室射血分数（LVEF）、左室最大射血速率（PER）、左室最大充盈速率（PFR）之间的差异。结果与正常对照组相比，松弛功能延迟组及假性正常化组的实时三维超声心动图舒张充盈参数PRF明显降低（P〈0．05），其他指标EDV、ESV、LVEF、PER无明显差异（P〉0．05）。结论实时三维超声心动图容积-时间曲线参数PFR可以评估早期左室舒张功能减低，为临床评价左室舒张功能提供了一个无创、快速、准确的新手段。     

实时三维超声心动图评价不同部位心肌梗死患者左心室收缩功能与同步性

目的 应用实时三维超声心动图（RT-3DE）评价前壁和下壁心肌梗死（心梗）患者左室整体和节段收缩功能及同步性,探讨梗死部位对左心室收缩功能及同步性的影响.方法 用RT-3DE对41例心梗患者（其中前壁心梗28例,下壁心梗13例）及30例健康体检者（对照组）进行17节段时间-容积曲线分析,获取心梗组及对照组的左室整体和节段舒张末期容积（EDV、rEDV）、收缩末期容积（ESV、rESV）、射血分数（EF、rEF）,以及16节段从QRS波起点到最小收缩容积时间的标准差和最大差值及其校正值（Tmsv 16-SD、Tmsv 16-Dif、Tmsv 16-SD%、Tmsv 16-Dif%）,其中Tmsv 16-SD%为左室收缩不同步指数（SDI）.结果 心梗组整体EDV、ESV及梗死节段的rEDV、rESV均较正常组增大,EF及rEF均减低,且前壁心梗组的这种改变较下壁心梗组更显著;心梗组SDI较正常组增大,前壁心梗组SDI较下壁心梗组增大,EF与SDI呈良好负相关.结论 前壁心肌梗死对左心室收缩功能及同步性的影响均较下壁心肌梗死大.     

Assessment of left ventricular volume and function by integration of simplified 3D echocardiography, tissue harmonic imaging and automated extraction of endocardial borders

BACKGROUND: Quantitative three-dimensional echocardiography (3DEcho) of left ventricle (LV) is still limited because of the need for manually tracing endocardial borders: this can increase observer variability depending on the quality of fundamental (FUND) 2D images. We tested the combination of a simplified 3DEcho technique for LV reconstruction with automated endocardial border detection (Digital Echo Quantification, DEQ) and tissue harmonic imaging (THI) for enhancement of endocardium-cavity interface. METHODS: Twenty-five consecutive patients with ischaemic heart disease and dilated or distorted LV underwent 3DEcho and gated-SPECT nuclear examinations evaluating: (a) end-diastolic and end-systolic volumes (EDV, ESV); (b) ejection fraction (EF); (c) volume/time curve (VTC). Thereafter, 3DEcho was applied to 47 patients with acute myocardial infarction (AMI) at pre-discharge and 6 months to evaluate remodelling. RESULTS: Integrated 3DEcho values in THI modality were obtained in 84% of patients and correlated well with nuclear data for EDV (r = 0.95, mean difference = -2.2 +/- 15.8 ml), ESV (r = 0.98, mean difference = -3.5 +/- 10.2 ml), and EF (r = 0.82, mean difference = 0.6 +/- 6.4%; all mean differences NS vs. 0), with an interobserver variability of 4.9, 5.7 and 8.2% for EDV, ESV and EF respectively. Automated VTC by 3DEcho in THI modality reproduced well that obtained by nuclear technique (r = 0.96) and allowed recognition of LV remodelling in 36% of patients at 6 months. Integrated 3DEcho values in FUND modality were obtained only in 52% of patients and showed much higher errors and interobserver variability. CONCLUSIONS: THI permits accurate 3D reconstruction of LV borders detected by DEQ, allowing automated VTC throughout the cardiac cycle as well as study of LV remodelling.     

Measurements of left ventricular volumes and ejection fraction with three-dimensional echocardiography: feasibility and agreement compared to two-dimensional echocardiography

Recent guidelines regard three-dimensional echocardiography (DE) derived measurements of left ventricular (LV) volumes and ejection fraction (EF) as the method of choice. The feasibility of 3DE and agreement between 2DE and 3DE was examined. Our hypothesis was that a number of patients can only be examined with 2DE in a patient population admitted to a general hospital. Hospitalised patients referred for echocardiography by residents on call who found grounds to perform a pocket-sized ultrasound examination (PCU) were included. A subsequent 2DE and 3DE was planned. 3DE was considered unfeasible in the presence of irregular heart rhythm and poor quality imaging (included inability to hold breath). Agreement was evaluated with correlation and Bland–Altman analyses. Of 273 consecutive patients examined with 2DE, 202 (74 %) had satisfactory 3DE images for LV volume and EF measurements. Reasons for exclusion of 71 patients from the 3DE study included irregular heart rhythm in 58 patients and poor quality images in 13 patients. Median LV end-diastolic volume was 146 mL with 3DE and 161 mL with 2DE (p < 0.001). The respective values for LV end-systolic volume were 76 mL and 83 mL (p < 0.001), and for LVEF 48 % and 49 % (p = 0.061). Optimal 3DE assessment of LV volumes and EF could only be performed in 3/4 of patients. A significant overestimation of LV volumes was observed in terms of 2DE versus 3DE, whereas no such difference was found for LVEF.     

Normal limits for left ventricular ejection fraction and volumes determined by gated single photon emission computed tomography--a comparison between two quantification methods

To compare gender-related normal limits for left ventricular (LV) ejection fraction (EF), end-diastolic and end-systolic volumes (EDV and ESV), obtained using two myocardial perfusion-gated single photon emission computed tomography (SPECT) quantification methods. A total of 185 patients were retrospectively selected from a consecutive series of patients examined for coronary artery disease (CAD) or for management of known CAD. Patients were included in the study group if they had normal or probably normal results with stress and rest perfusion imaging and if the combined interpretation of perfusion studies and gated rest studies showed no signs or suspicion of myocardial infarction. The gated SPECT studies were performed using a 2-day stress/gated rest Tc-99m sestamibi protocol. All patient studies were processed using CAFU and quantitative-gated SPECT (QGS), the two software packages for quantification of gated SPECT images. The lower normal limits for EF were higher for CAFU compared with QGS for both women (59% versus 53%) and men (54% versus 47%). The upper normal limits for EDV were also higher for CAFU compared with QGS for both women (133 versus 107 ml) and men (182 versus 161 ml). The differences between the software packages were small for ESV (women 44 versus 44 ml; men 69 versus 74 ml). Gender-specific normal limits need to be applied for LV EF and volumes determined by gated SPECT. Separate criteria for abnormal LV EF and EDV need to be used for women and men depending on the software package used.     

Clinical relevance of left ventricular volumes and function assessed by gated SPECT in paediatric patients

Left ventricular (LV) end-diastolic and end-systolic volumes (EDV, ESV) and ejection fraction (EF) can be measured by echocardiography and gated single photon emission computed tomography (G-SPECT). The literature is rich in works on G-SPECT in adults, but lacks data for children. This work evaluates the accuracy of G-SPECT in children, compared to echocardiography. PATIENTS AND METHODS: The study comprised 60 children. Eighteen with history of sickle cell disease, 5 dilated cardiomyopathy, 12 valvular heart disease and one with hyperlipidaemia. Other 24 children free from cardiac problems were included. All patients were given 185-370 MBq (5-10 mCi) of 99mTc-MIBI or 99mTc-Myoview. Resting G-SPECT was acquired 45-60 min after injection. LV volumes and EF were measured by G-SPECT and echocardiography. RESULTS: In all 60 cases, the correlation coefficients between both methods were 0.66 for EDV, 0.73 for ESV and 0.42 for EF. The 36 diseased children yielded fair to weak correlations for EDV, ESV and EF (r = 0.69, 0.74 and 0.41 respectively). The EDV was larger by echocardiography than G-SPECT (81.95 +/- 28.87 vs. 65.91 +/- 31.59 ml, p < 0.01). The ESV was also larger by echocardiography (39.13 +/- 15.96 vs. 23.44 +/- 18.04 ml, p < 0.01). The EF by G-SPECT (67.32 +/- 11.63%) was higher than by echocardiography (52.65 +/- 11.77%), (p < 0.01). The 24 normal subjects yielded almost the same level of weak correlation between both methods for EDV, ESV and EF (r = 0.59, 0.69, and 0.44 respectively). CONCLUSION: LV volumes and EF computed by G-SPECT correlated poorly with echocardiography in small ventricles. Consequently, G-SPECT has a limited clinical usefulness in paediatrics.     

应用实时三维超声心动图技术评价高血压病患者心室质量和功能的研究

目的应用实时三维超声心动图技术评价高血压病患者心室质量、容积和功能改变.方法在38例正常人、36例高血压无左室肥厚（NLVH）患者和31例高血压伴左室肥厚（LVH）患者中进行了超声心动图检查.应用二维超声双平面Simpson法测量左室舒张末期容积（EDV）、收缩末期容积（ESV）和射血分数（EF）,实时三维超声测量左室质量（LVM）及左室质量指数（LVMI）, 左、右心室容积、左房最大容积（Vmax）、最小容积（Vmin）及Vmin/Vmax.结果应用实时三维超声心动图16平面、8平面法、4平面法与2平面法、二维超声双平面Simpson法测量的左室EDV、ESV、EF各组测值之间差异有统计学意义.应用RT-3DE 16平面法测量的LVM、LVMI低于M型超声测值.与对照组比较,高血压NLVH组、LVH组三维超声测量的左室EDV、ESV均显著增高,高血压LVH组左室EF减低;高血压LVH组、NLVH组右室EDV、ESV均较对照组增大,两组左房Vmax、Vmin增加,LVH组Vmax/Vmax增加.结论实时三维超声技术能够定量评价高血压病患者左、右心室及左房容积和功能,测量左心室质量.     

立体三维超声心动图评价心肌病患者左心室收缩功能的应用价值

目的 探讨立体三维超声心动图(stereo three-dimensional echocardiography,S3DE)评估扩张型心肌病(DGM)及肥厚型心肌病(HCM)患者左心室收缩功能的准确性及其应用价值.方法 应用M型超声心动图(ME)、二维超声心动图(2DE)及S3DE测量DCM患者(20例)、HCM患者(20例)及正常对照者(20例)的左室舒张末期容积(EDV)、左室收缩末期容积(ESV)、每搏输出量(SV)及左室射血分数(EF),比较三组间及同组不同检测方法间的测量结果.结果 ①三组的S3DE同ME相比,EDV、ESV及SV差异均有统计学意义(P<0.01),S3DE同2DE相比,上述测值差异均无统计学意义(P>0.05);S3DE同ME、S3DE同2DE相比,EF测值仅在正常对照组(P<0.01)和HCM组(P<0.05)差异有统计学意义,DCM组三种方法所测EF差异均无统计学意义.②三组间S3DE各项指标的比较:与对照组相比,DCM组EDV、ESV均显著增加,EF显著减低(P均<0.01),而SV差异无统计学意义(P>0.05);HCM组仅SV明显增高(P<0.01),EDV、ESV及EF差异均无统计学意义(P>0.05).③S3DE所测EDV、ESV及EF同2DE相关性及拟合优度均好(r=0.778,0.876,0.932;R2=0.605,0.767,0.869;均P<0.01).④HCM组在控制了心率变量的影响后,心输出量同SV高度相关(r＝0.987,P<0.01).结论 S3DE能实时显示心脏立体结构,准确可靠地评估左室收缩功能,优于传统ME和2DE检测方法;EDV、ESV及EF仍是临床评估左室收缩功能较为有效的指标;S3DE所测SV有望成为评估心肌病患者早期左室收缩功能更为敏感、准确的指标.     

Relationship of number of phases per cardiac cycle and accuracy of measurement of left ventricular volumes, ejection fraction, and mass.

In cine cardiac magnetic resonance imaging (MRI) studies, for any preset imaging parameters the number of phases per cardiac cycle for a single slice is proportional to breath-hold duration. We investigated the relationship between the accuracy of measurement of left ventricular (LV) end-diastolic and end-systolic volumes (EDV and ESV, respectively), mass and ejection fraction (EF), and the number of phases acquired per cardiac cycle. Twelve adult volunteers underwent cardiac MRI and five complete LV functional studies were obtained with 8, 11, 14, 17, and 20 phases per cardiac cycle. We calculated LV volumes, EF, and mass for each acquisition, and compared them using the 20-phase acquisition as the reference standard. The scan duration was proportional to the number of phases acquired. There was a systematic underestimation of LV, EDV, and EF, with decreasing number of phases. Differences from the reference standard became significant for the 8-phase acquisition (p<0.05). Subgroup analysis showed that only those with slower heart rates (<65/min) had significant differences in EDV, but not in EF, for the 8-phase acquisition. For those with faster heart rates, no differences were detected between the different acquisitions. There were no significant differences between all acquisitions for the LV ESV and mass. We conclude that at least 11 phases per cardiac cycle are needed to maintain accuracy for cine cardiac MRI studies. Decreasing the number of phases per cardiac cycle beyond this cutoff may introduce significant error of measurement, particularly for the left ventricular EDV and EF and especially for those with bradycardia, and should be avoided.     

Measurement of Left Ventricular Volumes and Ejection Fraction in Patients with Regional Wall Motion Abnormalities Using an Automated 3D Quantification Algorithm

Accurate and rapid left ventricular (LV) ejection fraction (EF) measurement is crucial for patients with wall motion abnormalities (WMAs). Conventional 2D echocardiographic imaging has limitations. The recently developed software HeartModel (HM, Philips Healthcare, Andover, MA, USA) has shown promise in automated 3D quantification. However, the accuracy and detailed features of HM in measurements of LV volume and EF in patients with regional WMAs have not been carefully investigated. In the present study, echocardiographic imaging (EPIQ, X5-1, Philips Healthcare) was performed in 72 patients with WMAs. The LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF were measured by HM in three modes: without editing and with global and regional endocardial border editing (Auto 3D-NE, Auto 3D-GE and Auto 3D-RE, respectively). The conventional 2D Simpson's biplane method and manual 3D quantification (QLAB-3DQA software, Philips Healthcare), as the standard method, were used for comparison. Among the three HM modalities, Auto 3D-RE exhibited the best correlation with manual 3D in assessing EDV, ESV and EF (r?=?0.88, 0.93 and 0.91, respectively), although it took slightly longer (67.3 ± 13.0 s). Auto 3D-RE also exhibited a small degree of bias for the measurements (EDV: 11.7mL, ESV: 8.45mL, EF: –1.57%) and narrow limits of agreement. Heterogeneity of LV wall motion was defined to indicate the dispersion degree of WMAs. It associated with the difference in EF measurement between Auto 3D-RE and manual 3D (p?=?0.014, hazard ratio?=?5.19). In patients with WMAs, HM with regional contour editing enables accurate and efficient evaluation of LV volume and EF.