Harmonic imaging improves estimation of left ventricular mass

OBJECTIVES: To assess the effect of tissue harmonic imaging (THI) on assessment of left ventricular mass index (LVMI) measurements by M-mode trans-thoracic echocardiography, when compared with magnetic resonance imaging (MRI). METHODS: 20 hypertensive male subjects were studied. LVMI was measured in all subjects by both gradient-echo MRI (Lscelsint Prestige 1.9 T) and by transthoracic echocardiography (ATL HDI 5000). M-mode echocardiography recordings were taken for each patient, two with fundamental imaging (FI) and two using THI in a randomised order and the images unlabelled. Recordings were analysed off-line, by a blinded observer. LVMI by MRI was calculated using Simpson's rule on serial short axis slices of 8 mm thickness. Data are expressed as mean +/- SD. RESULTS: There was a difference in LVMI measurements between FI and THI (LVMI) (79 +/- 20 vs. 93 +/- 25 g2; p < 0.001). A lower mean difference was obtained by THI, compared to FI, when compared with MRI (2 +/- 15 vs. -32 +/- 22 g2; p < 0.001) suggesting that FI underestimates LVMI. Inter-observer variability was similar between THI and FI (4.5 +/- 15 vs. 6.4 +/- 15 g2; p = 0.46). CONCLUSION: In hypertensive males, M-mode echo derived from FI underestimated LVMI. These results imply that widely accepted reference ranges for LVMI using FI are not applicable when THI is used.     

High-frame-rate tissue harmonic imaging enhances anatomic M-mode sections of the left ventricle in short-axis view.

BACKGROUND: High-frame-rate echocardiography (HFRE) and tissue harmonic imaging (THI) may improve image quality, thereby enabling anatomic M-mode sections of left ventricular (LV) wall segments to be visualized in various planes in the short-axis view. OBJECTIVES: The goals of this study were to compare image quality between HFRE and conventional-frame-rate echocardiography (CFRE) and between fundamental imaging (FI) and THI, and to obtain anatomic M-mode values of basal short-axis LV segments from healthy subjects for use in the evaluation of abnormal segments in patients with myocardial infarction (MI). METHODS AND RESULTS: The study included 28 healthy subjects and 15 patients with MI who underwent 2-dimensional echocardiography with an ultrasonographic system equipped with THI and anatomic M-mode. Left ventricular image cineloops at the basal short-axis view that were obtained with 3 combinations of imaging techniques (FI + CFRE, FI + HFRE, and THI + HFRE) were digitized and displayed side-by-side in random order for comparison by blinded readers. M-mode sections were done in 3 planes: anteroseptal-posterior, inferoseptal-lateral, and anterior-inferior basal segments. The THI + HFRE combination showed the best image quality with significant reduction in noise artifacts, resulting in a good signal-to-noise ratio and good tractability of all LV segments by anatomic M-mode. In healthy subjects, significant intersegmental differences existed in the diastolic and systolic thicknesses and in the percent systolic thickening of LV segments. In patients with MI, LV systolic thickening was significantly decreased in abnormal segments. No significant differences were noted in ejection fraction and fractional shortening among the 3 anatomic M-mode planes. CONCLUSION: High-frame-rate tissue harmonic imaging improved image quality, thereby allowing reproducible anatomic M-mode measurements in various planes in the short-axis view and providing a convenient objective evaluation of global and regional LV function.     

Measurement of left ventricular volumes by 3-dimensional echocardiography with tissue harmonic imaging: a comparison with magnetic resonance imaging.

We hypothesized that tissue harmonic imaging (THI) in comparison with fundamental imaging (FI) would improve endocardial border detection, and therefore in combination with 3-dimensional echocardiography (3D echo), it would be a precise method for left ventricular (LV) volume measurement. Ten healthy subjects and 18 consecutive patients with dilated hearts underwent estimation of LV volumes by magnetic resonance imaging (MRI) and transthoracic 3D echo with THI and FI. In patients, the agreement between MRI and 3D echo was closer with THI in comparison with FI for assessment of LV volumes. Thus the mean +/- 2 SD of differences between MRI and 3D echo with THI versus FI, respectively, was -6.4 +/- 40.0 mL versus -17.4 +/- 57.6 mL (P <.01) for the end-diastolic volume (EDV), and 0.0 +/- 26.6 mL versus -8.1 +/- 35.6 mL (P <.01) for the end-systolic volume (ESV). In patients, THI in comparison with FI approximately halved observer variation on EDV and ESV. In healthy subjects, only ESV showed significantly reduced observer variation by THI. In conclusion, because THI demonstrated a clinically relevant reduction in observer variation and a closer agreement to the MRI technique in patients with dilated hearts, it should replace FI in LV volume measurements.     

Feasibility and accuracy of left ventricular volumes and ejection fraction determination by fundamental, tissue harmonic, and intravenous contrast imaging in difficult-to-image patients.

The need to enhance the echocardiographic determination of left ventricular ejection fraction is greatest in patients with suboptimal images. Intravenous contrast (CON) and tissue harmonic imaging (THI) are 2 important methods for enhancing endocardial border definition. However, the comparative feasibility and accuracy of THI and contrast-enhanced power harmonic imaging in difficult-to-image patients have not been examined. We assessed the comparative accuracy of THI and CON in determining EF and ventricular volumes in patients with suboptimal fundamental images. We demonstrated that CON is feasible and exhibits a greater correlation with ejection fraction and ventricular volumes determined by radionuclide angiography (standard of comparison) than THI in this difficult-to-image population, with no reported side effects. For both ejection fraction and ventricular volumes, the observer variability was least for CON, intermediate with THI, and greatest for fundamental imaging.     

Comparison between fundamental and second-harmonic imaging echocardiography for calculation of left ventricular mass in children

In adults, calculation of left ventricular mass (LVM) has been shown to give higher values when based on M-mode measurements obtained by the second-harmonic imaging (SHI) technique than with the older fundamental imaging (FI) technique. No information is available in paediatric subjects. This study, therefore, compares LVM calculated from measurements obtained with SHI and FI in 14 children, aged 6.9-13.0 years. M-mode tracings were obtained in accordance with American Society of Echocardiography (ASE) recommendations. Three experienced sonographers performed measurements on each subject with both SHI and FI. The mean value was used in all calculations. LVM was calculated according to ASE convention and indexed by body surface area. LVM mean values were 58.9 +/- 9.7 g m(-2) for SHI and 57.8 +/- 8.2 g m(-2) for FI (P = 0.45). This preliminary study in a small group of paediatric subjects demonstrates no systematic differences between FI and SHI modalities in the calculation of LVM. The likely explanation is that the left ventricular endocardial border is usually well visualized with SHI as well as with FI in children.     

谐波成像后应用超声背向散射积分评价陈旧性心肌梗塞心肌残存收缩能力

目的:探讨组织谐波成像(THI)后应用超声背向散射积分(IBS)评价陈旧性心肌梗塞(OMI)心肌残存收缩能力的优点。方法:前壁陈旧性心肌梗塞20例定为OMI组,健康人22例定为对照组。应用Agilent-5500型超声仪,获取两组左室乳头肌水平短轴观的THI和基波成像(FI)画面,记录左室前间隔心肌组织IBS值和IBS值心动周期变动量(CVIBS)。运用t检验进行两组IBS参数的显著性检验。结果:THI后和FI时,OMI组左室前间隔IBS值均显著高于对照组(P<0.05,P<0.01),CVIBS均显著低于对照组(P<0.01,P<0.01)。与FI时比较THI后OMI组左室前间隔IBS值显著增高(P<0.05),CVIBS显著增大(P<0.05)。结论:THI后应用IBS评价OMI心肌残存收缩能力敏感度增高。     

Does second harmonic imaging improve left ventricular endocardial border identification at higher heart rates during dobutamine stress echocardiography?

BACKGROUND: The increased heart rate during dobutamine stress echocardiography (DSE) may impair endocardial border visualization. Second harmonic imaging (SHI) enhances left ventricular (LV) border visualization compared with conventional fundamental imaging (FI) at rest. However, its role during DSE is not well established yet. OBJECTIVE: Our objective was to compare the additional value of SHI to FI for the LV endocardial border visualization during various stages of DSE. METHODS: Eighty patients underwent DSE. Imaging was performed with both FI and SHI at rest and at low-and peak-dose dobutamine infusion. Endocardial border visualization was assessed by using a 16-segment/3-point score (0 = well visualized; 1 = poorly visualized; 2 = not visualized). RESULTS: Heart rate increased from rest (70 +/- 13 bpm) to low-dose dobutamine (77 +/- 17, P <.01) and showed further increase at peak dose (129 +/- 16, P <.001 versus low dose). There was a higher prevalence of segments with an invisible LV endocardial border with FI compared with SHI at rest (9.4% versus 6.2%, P <.0001), at low dose (10.8% versus 6.3%, P <.0001), and at peak dose (15.0% versus 8.2%, P <.0001). There was an increase in the number of segments with an invisible border from rest to peak stress by FI (P =.0001), whereas the difference was less significant for SHI (P =.07). CONCLUSION: Second harmonic imaging improves visualization of the LV endocardial border compared with FI during DSE. The advantage of SHI over FI is more marked at higher heart rates than at rest.     

超声应变分析扩张型心肌病治疗前后肺动脉压力和右心功能改变

目的:本文研究扩张型心肌病(Dilated cardiomyopathy,DCM)引起的肺动脉高压经治疗后肺动脉压力及右心功能的改变。方法:超声应变技术测量60例左室受累的DCM患者治疗前后肺动脉压及右室应变的变化。结果:DCM合并肺动脉高压的患者(肺动脉收缩压≥35 mmHg),左室收缩及舒张功能较差。该类患者经保守治疗后,左室射血分数增高(P=0.046),肺动脉收缩压减低(P<0.001),三尖瓣侧瓣环收缩期位移(TAPSE)无变化(P=0.102),右心室游离壁应变升高(P<0.001)。与TAPSE相比,超声应变指标与核磁共振测量右室射血分数的相关性更优(r=0.808,P=0.008)。结论:超声应变较传统超声评估DCM治疗后右室功能改变更为敏感。     

Is the Technically Limited Echocardiographic Study an Endangered Species? Endocardial Border Definition with Native Tissue Harmonic Imaging and Optison Contrast: A Review of 200 Cases

OBJECTIVE: Our goal was to determine whether contrast adds diagnostic value to both fundamental and native tissue harmonic imaging (NTHI) for endocardial border definition. METHODS: Two hundred consecutive patients who underwent stress echocardiography imaging were studied in either fundamental (n = 52) or NTHI mode (n = 148) with an Acuson Sequoia echocardiographic system. Contrast agent (Optison) was administered (0.5 to 1 mL) for enhancement of endocardial borders. Two- and 4-chamber views were analyzed before and after administration of contrast at peak stress for grading of 5 endocardial border segments. Scores from 0 to 5 were assigned to each study for all the images both before and after contrast (0 = 0 segments completely visualized; 5 = 5 segments completely visualized). RESULTS: The use of Optison contrast significantly enhanced border definition when imaging was performed in either fundamental or NTHI mode. Addition of contrast resulted in better endocardial border definition in fundamental mode (4.1 + or - 1.0 versus 2.3 + or - 1.3, P <.001). However, in NTHI mode, the presence of contrast resulted in enhanced definition of endocardial border compared with its absence (4.8 + or - 0.5 versus 3.3 + or - 1.1, P <.001). The combination of NTHI and contrast resulted in more visualization of endocardium when compared with the combination of fundamental imaging and contrast (4.8 + or - 0.5 versus 4.1 + or - 1.0, P <.001). In addition, interobserver agreement for border detection increased from 83% in fundamental mode without contrast to 95% with the use of NTHI with Optison (P <.001). CONCLUSION: As defined in 200 cases, the combination of NTHI with Optison contrast results in nearly complete and consistent endocardial border definition.     

组织谐波显像技术在肝胆系统疾病临床诊断中的应用

目的:探讨组织谐波显像技术(THI)在肝胆系统疾病临床诊断中的应用。方法:选择2003年—2007年常规超声检查图像不理想的78例患者,对其常规基波显像(FI)检查及THI检查结果进行比较分析。结果:肝病组及胆系疾病组在二维超声FI基础上,加入THI后,能很明显地提高灰阶对比度,脏器的内部结构及边缘回声显示有明显的改善,脏器内实性肿块的轮廓清晰度有明显改善。结论:THI可明显提高FI的图像质量,提高二维检出率,具有较高的临床诊断价值。     

组织谐频成像与基频成像在心脏声像图中的对比观察

目的:探讨组织谐频成像（THI）与常规基频成像（FI）的对比观察，研究THI改善声像图质量，增强图像的显现力。方法：对150例（标准受检100例、透声差受检50例）心脏（正常或异常）进行观察，分析两种检查的图像质量。结果：FI成像标准受检图像显示优良率81％，透声差受检图像显示优良率64％。THI成像标准受检图像显示优良率91％，透声差受检图像显示优良率88％。结论：无论标准受检或透声差受检THI的图像质量均较FI的图像质量明显改善，可提高诊断的准确性。     

组织谐波显像诊断胰腺癌的临床应用

目的通过常规基波显像(FI)与组织谐波显像(THI)的对比观察,探讨组织谐波显像诊断胰腺癌的临床应用价值。方法对45例胰腺癌患者(肿块直径小于4cm,无远处转移)进行FI和THI检查,对2种方法所得图像质量进行对比,分析2种检查方法的诊断价值。结果在观察胰腺病灶的大小、边界、内部回声特点、胰管回声及肿块与周围血管的关系等方面,组织谐波显像明显优于基波显像。结论本研究表明,THI可提高胰腺肿块的图像质量,提高病变显示的清晰度及信息量,从而提高诊断准确率。     

Atypical pseudoaneurysm after mitral valve replacement: Doppler echocardiographic diagnosis.

Ventricular pseudoaneurysm is a rare complication of mitral valve replacement or myocardial infarction. Typically, a ventricular pseudoaneurysm appears as an echocardiographic lucency posterior and lateral to the left ventricle and is best seen from the parasternal long axis and apical four-chamber views. We present an atypical case of left ventricular pseudoaneurysm that tracts posterior and lateral to the right ventricle that was best visualized from the subcostal and low parasternal windows with medial angulation. Doppler imaging confirmed the diagnosis by demonstrating to-and-fro flow between the left ventricle and the cavity located behind the right ventricle. This case emphasizes the importance of the use of multiple echocardiographic windows.     

Echocardiographic imaging of technically difficult patients in the intensive care unit: use of optison in combination with fundamental and harmonic imaging.

Previous studies of intravenous contrast agents have excluded patients in the intensive care unit. These patients remain among the most technically difficult to image with ultrasound. We studied the effect of different imaging modalities with and without intravenous contrast (Optison) on endocardial border visualization during echocardiography. Fifty patients in the intensive care unit (32 men, 24 on mechanical ventilator, 10 with chest bandages; mean age, 59 years; mean weight, 91.7 kg; mean height, 67.6 inches) were considered to have technically difficult images when the endocardium could not be visualized in at least 2 of the 6 segments in either apical view. Each patient was studied with the use of fundamental (F), harmonic (H), fundamental + Optison (F + O), and H + O techniques, with standard long-axis, short-axis, and apical 4- and 2-chamber views. Intravenous Optison (0.5 to 1.5 mL) was given before F + O and H + O imaging. There were no contrast-related side effects noted. All images were stored digitally in a quad-screen format. For each set of images, segments (n = 22) were given an endocardial border visualization score of 0 if not visualized, 1 if visualized in either systole or diastole, and 2 if visualized in both. There was stepwise improvement in endocardial border visualization, with mean endocardial border visualization score of 1.09 +/- 0.83 (F), 1.33 +/- 0.81 (H), 1.64 +/- 0.62 (F + O), and 1.90 +/- 0.35 (H + O). There was a statistically significant difference between each group (P <.001). The incremental benefit of Optison was greater with harmonic imaging than with fundamental (P <.001). The use of Optison is safe and effective in the intensive care unit. In combination with harmonic imaging, contrast provides maximal endocardial border delineation during echocardiographic imaging of technically difficult patients in the intensive care unit.     

实时三维超声心动图估测左心室容量的实验研究

目的初探实时三维超声心动图(3DE)估测心室容量的可行性和准确性.方法应用Philips公司实时3DE系统采集19只离体猪心金字塔形数据库,结合相应测量软件用心尖长轴系列平面法分别测量左室容量,并与二维双平面Simpson法和猪心左室排水法实测值比较.结果从方差分析、SNK检验及直线相关分析看:实时3DE 16平面法(23.31±14.29)ml、8平面法(23.42±14.56)ml估测左室容量值与猪心左室排水法实测值(23.79±14.78)ml差异无统计学意义(P＞0.05),实时3DE 2平面法(17.94±10.46)ml和二维超声双平面Simpson法(19.67±13.46)m1测值与排水法实测值差异则有统计学意义(P＜0.05).而且实时3DE 16平面和8平面法测值与排水法实测值高度相关(r=0.98,P＜0.0001),二维超声双平面Simpson法则较逊(r=0.89).结论实时3DE是心室容量准确估测的又一可靠手段.     

Serial echocardiographic observations in patients with primary systemic amyloidosis: an introduction to the concept of early (asymptomatic) amyloid infiltration of the heart

Echocardiography was used for the serial assessment of 27 patients with primary systemic amyloidosis. Thirteen patients had no clinical cardiac deterioration between the two echocardiographic studies (group 1), whereas in 14 patients (group 2), congestive heart failure or arrhythmias (or both) appeared or worsened during a mean observation period of 19 months. The only echocardiographic changes in group 1 were a mild increase in left ventricular mass and a mild decrease in left ventricular wall systolic thickening. Patients in group 2 had significant changes in left ventricular wall thickness (mean increase, 34%), in left ventricular mass (mean increase, 42%), in right ventricular wall thickness (mean increase, 78%), in left atrial size (mean increase, 19%), in left ventricular mass/voltage ratio (mean increase, 68%), in left ventricular radius/thickness ratio (mean decrease, 29%), and in left ventricular fractional shortening (mean decrease, 13%). Significant correlations were found in group 2 between changes in systolic and diastolic blood pressure and changes in ventricular wall thickness and mass. Changes in left ventricular systolic function did not correlate significantly with changes in other clinical, electrocardiographic, or echocardiographic measurements. In six cases (two in group 1), in which amyloid infiltration of the heart was proved by myocardial biopsy or autopsy, the only echocardiographic abnormality when the patients were asymptomatic was a moderate increase in left or right ventricular wall thickness. We found that M-mode and two-dimensional echocardiographic examinations can substantiate progressive amyloid infiltration of the heart and are useful tools for the noninvasive serial assessment of patients with primary systemic amyloidosis.     

Transcranial sonography of the brain parenchyma: comparison of B-mode imaging and tissue harmonic imaging

Transcranial color-coded Duplex sonography (TCCS) has been used for the identification of cerebrovascular disorders. Recently, its value in the diagnosis of disorders of the brain parenchyma has been proposed. The object of this study was to determine systematically the echo pattern of the brain parenchyma and to compare conventional B-mode imaging with tissue harmonic imaging (THI). Transcranial sonography (TCS) was performed in 54 healthy individuals through the temporal bone window using conventional B-mode imaging and THI by two experienced investigators. Identification rates for several brain structures were assessed, and the quality of depiction of each method was graded semiquantitatively. In addition, several parts of the ventricular system and the basal cerebral cisterns were measured. Four subjects did not have an adequate bone window for transcranial examination. In the remaining people, the bone window was assessed to be adequate (59%) or excellent (33%). In the majority (> 80%), TCS allowed an unequivocal identification of various brain structures. Inter-rater variability of the assessments of tissue echogenicity and measurements of the ventricular width were found to be low for several structures (e.g., brainstem, thalamus, or 3rd ventricle). The echo pattern of brain tissue in THI is identical to that described for B-mode imaging. Using THI, contours of brain structures were typically visualized more clearly and the reproducibility of measurements was more consistent. In our experience, insonation of the contralateral lobes was limited when depths were higher than 12 cm using THI. In conclusion, TCS allowed the sonographic examination of the brain parenchyma in the majority of our subjects. THI substantially improves the identification of parenchymal structures when the depth is below 12 cm.     

组织谐波成像在腹部脏器的临床应用

目的 探讨组织谐波成像技术在腹部脏器的临床应用价值。方法 分别采用常规基波成像(FI)，及组织谐波成像(THI)对138例腹部脏器正常组及疾病组二维声像图及诊断检出率进行比较。结果 THI明显改善了FI状态下二维图像质量：正常腹部脏器结构及层次显示清晰，疾病组声像图特征明显，提高了检出率及鉴别诊断水平；同时，THI明显减少伪像，增加细微组织结构分辨能力，在胆囊疾病诊断中尤其有意义。结论 随着技术的不断改善，THI能为超声提供更有诊断价值的信息。     

超声心动图对主动脉缩窄伴左心室收缩功能降低患者的诊断及术后随访价值

目的探讨伴有左心室收缩功能降低患者主动脉缩窄的特点以及超声心动图在其诊断、术后随访中的临床应用价值。方法选取我院主动脉缩窄患者102例,根据左心室射血分数（EF）数值将其分为EF降低组（EF〈60%）及EF正常组（EF≥60%）,通过比较两组患者超声表现,总结伴有左心室收缩功能降低的主动脉缩窄的特点。对EF降低组中手术者分别于术后1 d、术后1个月和术后6个月行超声心动图随诊,并与术前对比。结果 EF降低组17例,经增强CT或手术证实,超声确诊15例,误诊2例。EF降低组与EF正常组相比,孤立型主动脉缩窄多见,往往伴左心室舒张末期内径重度增大、左心室心内膜回声粗糙、冠状动脉近段内径增宽,两组比较差异有统计学意义（χ2=8.745、13.246、32.750、8.330,P均〈0.05）;两组在狭窄程度、缩窄形态、室间隔及室壁增厚构成上差异无统计学意义（Z=-1.532,χ2=0.222、0.678,P均〉0.05）。EF降低组中12例患者经手术矫治并术后超声随诊,术后1 d、1个月、6个月各时段狭窄修复处内径及压差、左心室舒张末期内径与术前比较差异均有统计学意义（t=-9.969、-9.987、-11.265,t=6.463、5.108、5.632,t=4.986、5.713、7.219,P均〈0.05）。左心室EF值在术后1 d与术前比较差异无统计学意义（t=-2.217,P〉0.05）;在术后1个月、术后6个月与术前比较差异有统计学意义（t=-3.999、-9.198,P均〈0.05）,术后6个月左心室EF值均值〉60%。结论伴有左心室收缩功能降低的主动脉缩窄有特征性超声表现,超声心动图对其诊断及术后评价具有重要价值。     

Reference values for echocardiographic measurements in urban and rural populations of differing ethnicity: the Strong Heart Study.

Discrepancies in reported reference values for left ventricular (LV) dimensions and mass may be due to imaging errors with early echocardiographic methods or effects of subject characteristics and inclusion criteria. To determine whether contemporary echocardiographic methods provide stable normal limits for left ventricular measurements in different populations, M-mode/2-dimensional echocardiography was applied in 176 American Indian participants in the Strong Heart Study and 237 New York City residents who were clinically normal. No consistent difference in any measure of LV size or function existed between populations. Upper normal limits (98th percentile) for LV mass were 96 g/m(2) in women and 116 g/m(2) in men and 3.27 cm/m for LV chamber diameter normalized for height. Thus contemporary M-mode/2D echocardiography provides reference ranges for LV measurements that approximate necropsy measurements and have acceptable stability in apparently normal white, African-American/Caribbean, and American Indian populations.