自然组织谐波成像对冠心病室壁运动的评价

目的：评价自然组织谐波成像（NTHI）技术在对冠心左内膜的识别和左室壁运动评价方面的应用价值。方法：对33例冠心病患者行常规和NTHI二维超声检查。采用胸骨旁左室长轴、心尖四腔、二腔切面、心内膜识别分4级,壁运动分析采用16节段法。结果：NTHI改善了57．2％（302／528）节段的心内膜识别,改变了12．7％（67／528）节段的室壁运动级别。结论：应用自然组织谐波技术可改善冠心病病人心内膜的超声识别,进而增加对冠心病病人室壁运动分析的准确性。     

Improvement of endocardial border delineation in suboptimal stressechocardiograms using the new left heart contrast agent SH U 508 A

Recent studies have shown that the saccharide based echocardiographic contrast agent SH U 508 A opacifies the left ventricle after i.v. injection, thus possibly improving endocardial border definition. This study was performed to determine whether SH U 508 A can enhance the wall motion analysis in suboptimal echocardiographic images at rest and following pharmacological stress. Ten male patients (mean 58 years) exhibiting ≥30% endocardial border dropout were examined prior to a diagnostic left heart catheterization. Five patients were stressed with Dobutamine, 5 with Dipyridamole. The wall motion was assessed visually (qualitatively) as well as computer-aided (quantitatively). The concordance between left ventricular angiography as ‘gold standard’ and resting echocardiography regarding the wall motion analysis was significantly improved from 64.5% to 90.3% following the injection of SH U 508 A (p < 0.05). A delineation score (0 = not delineated, 1 = delineated) of 12 individual wall segments was used. The mean delineation score at baseline was 6.1 ±1.4 at rest and 6.6 ±1.9 during stress. SH U 508 A significantly (p < 0.01) increased the score to 9.6 ±1.9 and 10.3 ±1.7, respectively. The intraobserver variability for assessing the delineation score was significantly (p < 0.04) improved by SH U 508 A. SH U 508 A, however, did not improve the quantitative assessment of the left ventricular function. Only 40% of the patients could be analyzed following SH U 508 A injection. No severe adverse reactions were seen. SH U 508 A led to a significant, clinically important, improvement in the interpretation of stress echocardiograms in patients with inconclusive routine echocardiograms.     

Star algorithm: detecting the ultrasonic endocardial boundary automatically

In clinical practice, interuser variability, high computational cost and low image quality are always big problems that puzzle the clinical application of computer-aided echocardiographic boundary detection. Star algorithm (StaA) is a new endocardial boundary detector that has been designed to overcome these problems. The purpose of the paper is to present the detection details of the algorithm and evaluate its clinical value. The main elements of StaA are radial search technique, cost function-driven system and self-designed edge detector. The algorithm has four main steps: image preprocessing, initial left ventricular chamber detection, left ventricular chamber center detection and left ventricular endocardial boundary detection. StaA was performed on 50 pairs of end-diastolic (ED) and end-systolic (ES) echocardiographic images, which were divided into high image-quality group (HImQ) and low image-quality group (LImQ). The results of the test were analyzed in two ways: 1. Compared with the manually-traced boundary, the mean relative radial error (MRRerr) of the computer-detected boundary was 12.07% and there is no significant difference of MRRerr between HImQ and LImQ. 2. The two-dimensional (2-D) ejection fraction calculated by the computer detected boundary (EFa) can be used interchangeably with that calculated by the manually-traced boundary (EFm). The test proves that simple and effective methods can also make the echocardiographic boundary detector automatic, quick and robust.     

多相位节段性左室壁运动定量测定及其对冠心病的诊断价值

本研究在微机数字图象处理系统辅助下,应用多帧多相位节段性左室壁运动定量测定法分析了60例正常人和25例冠心病者二维超声心动图的左室壁运动。由本法给出的反映左室壁运动的指标r和b在冠心病者左室缺血节段其值显著降低;r和b检测节段性左室壁运动障碍的敏感性分别为84％和88％,特异性分别为100％和95％。结果表明本法能反映左室壁收缩期各时相的运动状况,对节段性室壁运动障碍的敏感性及特异性高。本法与二维超声心动图结合可为无创性定量诊断冠心病提供一种新的方法。     

应用门控心肌显像定量分析室壁局部运动对心功能的影响

目的 利用定量门控^99mTc-MIBI心肌显像评价左心室室壁各节段运动对左心功能的影响。 方法 对768例患者进行门控^99mTc-MIBI心肌显像,采用QGSPECT程序定量获得20节段的局部室壁运动(WM)及左心室射血分数(LVEF)值。分析LVEF与心室各节段WM的关系。 结果 所得4个公共因子分别代表不同的节段信息,F₁反映了心尖、侧壁的近心尖和中段、前壁、下壁和下间隔的近心尖的信息。F₂反映了前壁和下间隔的中段、整个前间隔的信息。F₃反映了前壁和下侧壁的基底段的信息。F₄反映了下壁的中段和基底段及下间隔基底段的信息。利用多元线性回归分析的方法得出其对LVEF影响的大小顺序为F₁＞F₃＞F₂＞F₄(标准回归系数分别为0.633、0.471、0.415、0.169,P＜0.001)。 结论 应用定量门控心肌显像获得的WM与LVEF有显著的相关性,影响最大的包括心尖、侧壁的近心尖和中段、前壁、下壁和下间隔的近心尖。     

Comparison of 2 Myocardial Velocity Gradient Assessment Methods During Dobutamine Infusion with Doppler Myocardial Imaging

Myocardial velocity gradient (MVG) has been shown to be the best quantitative parameter for the detection of ischemic myocardium during dobutamine infusion with the use of Doppler myocardial imaging. MVG has been previously assessed by velocity measurements across the thickness of the myocardium at the time of visually selected maximal color brightness (thickness-velocity plot method). We hypothesized that MVG could be assessed by velocity measurements throughout the cardiac cycle in the subendocardium parallel to the endocardial boundary to the left ventricular cavity and in the subepicardium parallel to the epicardial boundary (time-velocity plot method). This study was designed to compare MVG obtained from the thickness-velocity plot method and from the time-velocity plot method in quantifying dobutamine-induced changes in myocardial wall motion in 8 phases of the cardiac cycle on color M-mode Doppler myocardial imaging recordings of the left ventricular posterior wall performed in 8 conscious dogs at baseline and at steady state during dobutamine infusion (10 μg/kg per minute). For both methods, MVG was considered present if its mean value was significantly different from zero and if endocardial and epicardial velocities were significantly different. There was close agreement between the 2 methods. MVG was present during the preejection period, systole, rapid ventricular filling, and atrial contraction. Dobutamine induced a significant increase in MVG during the preejection period (from 2.64 ± 0.83 to 4.05 ± 0.81 seconds^-1 ), systole (from 2.14 ± 0.59 to 6.08 ± 2.20 seconds^-1 in early systole, from 1.90 ± 1.06 to 5.31 ± 2.95 seconds^-1 in mid systole, from 1.37 ± 0.57 to 2.44 ± 0.53 seconds^-1 in end systole), and rapid ventricular filling (from 3.06 ± 1.12 to 7.82 ± 2.58 seconds^-1 ), related to a greater rise in endocardial than in epicardial velocities. The time-velocity plot method showed that ejection and diastole were 11% and 28% decreased during dobutamine infusion, respectively, as heart rate was 31% increased. Thus according to our quantitative criteria, both MVG assessment procedures enabled objective interpretation of dobutamine effects on left ventricular wall motion. In addition, the time-velocity plot method provided automatic detection of peak velocity, timing, and duration of wall velocity changes over time. (J Am Soc Echocardiogr 1999;12:22-31.)     

组织追踪技术与冠状动脉造影对比评价左室节段性室壁运动异常

目的探讨超声心肌组织追踪（TTI）技术评价左室节段性室壁运动异常的临床价值。方法采用TTI技术对41例健康人、60例冠心病患者于心尖四腔切面、两腔切面及左室长轴切面检测左室后间隔、侧壁、前壁、下壁、前间隔及后壁收缩期位移,并与冠状动脉造影和二维超声心动图结果比较。结果冠心病患者左室壁运动位移异常节段表现为位移值的降低及其彩色编码显像和曲线波形的改变,TTI诊断冠心病的阳性检出率为87．7％,二维超声心动图诊断冠心病的阳性检出率为68．0％,二者差异有统计学意义（P〈0．05）。结论TTI技术能够无创、快速、客观地定量和定性分析左室壁节段性运动异常,明显提高左室壁节段性室壁运动异常的检出率。     

超声造影检测心肌梗死患者受损左室壁的价值

目的探讨超声造影在检测心肌梗死患者左室壁受损范围中的价值。方法对75名发生心肌梗死的患者进行实时心肌造影,分别于超声造影前后观察心内膜边界显示情况,评价和比较节段室壁运动情况。结果超声造影后左室心内膜边界的显示较造影前明显清晰,受损节段与未受损节段的对比增强。以冠状动脉造影结果为标准,造影检测的灵敏度、特异度和准确度均高于造影前（p〈0．05）。结论实时超声造影能有效增强左室心内膜边界显示和受损心肌边界显影,提高对左室壁受损范围检测的准确性。     

关于一个全自动勾画超声左心室内膜算法的初步研究

目的 :本文叙述一个新的全自动勾画心内膜算法的初步研究情况 ,这个算法将是全自动心功能定量分析的基础。该算法应用中心起源的形心搜索、用改进的 Sobel算子进行的放射形边界探测和依据相邻离心距差进行的边界点修正。方法 :我们用自动勾画 1 2张超声图像 (其中 6张高质量的图像 ,6张低质量的图像 )中心内膜边界的方法来检测该算法。结果 :在 1 2张超声图像中我们的算法成功地勾画出 7张图像中的心内膜 ,其中包括一张低质量的图像。结论 :虽然该算法还需要改进 ,但 58%的勾画成功率已相当令人满意     

Assessment of left ventricular volume and mass by cine magnetic resonance imaging in patients with anterior myocardial infarction intra-observer and inter-observer variability on contour detection

Remodeling of the left ventricle after myocardial infarction can be documented by calculation of left ventricular volume and mass, using endocardial and epicardial tracings of multilevel multiphase short-axis cine magnetic resonance (MR) imaging series. We assessed left ventricular volume and mass from 8 slices and during 12 phases of the cardiac cycle in seven patients with an anterior wall myocardial infarction; one patient was studied twice, leaving eight MR examinations to be evaluated. Purpose of this study was to assess the intra-observer and interobserver variability of epicardial volume, endocardial volume, and left ventricular mass from contours manually traced by two independent observers. For the eight MR examinations, epicardial volume was found to be 292 ± 51 ml (mean ± SD) at end-diastole, which decreased to 237 ± 55 ml at end-systole. Endocardial volume was 141 ± 31 ml at end-diastole, which decreased to 79 ± 27 ml at end-systole. Left ventricular ejection fraction was 45 ± 8%. Mean left ventricular mass, when averaged over all patient studies and all phases, was 159 ± 30 g. Intra-observer and inter-observer variability were found to be 3.5% and 5.2% for endocardial volume, 2.0% and 2.5% for epicardial volume, and 3.6% and 3.6% for left ventricular mass, respectively. The contour analysis showed a statistically significant phase effect in the endocardial contour in the midventricular slices, which was resolved after establishing a more precise definition for the tracing of the endocardial border. In conclusion, left ventricular volume and mass in patients with an anterior wall myocardial infarction can be assessed with high reproducibility and relibility from manual contour tracings. A precise protocol for the definition of endocardial and epicardial contours is required to obtain reproducible and reliable results.     

Objective assessment of left ventricular wall motion from contrast-enhanced power modulation images.

There is no method to objectively evaluate left ventricular (LV) function from contrast-enhanced images. We tested the feasibility of evaluating regional LV function by using power modulation imaging. In protocol 1, 9 anesthetized closed-chest pigs were studied. Images were obtained during contrast infusion at baseline, during LAD occlusion and reperfusion. In protocol 2, images were obtained in 20 patients (14 wall-motion abnormalities; 6 controls) during contrast enhancement. Off-line, frame-by-frame, semiautomated endocardial border detection was followed by color encoding of endocardial motion, followed by segmentation and calculation of regional fractional area changes. In all animals, coronary occlusions resulted in hypokinesis and decreased fractional area changes in LAD-related segments only, which were reversed during reperfusion. In patients, wall-motion analysis was in agreement with an expert reader of dynamic images in 92.5% segments, with interobserver variability of 12.5%. Color encoding of endocardial motion from contrast-enhanced power modulation images allows accurate quantitative assessment of regional LV function.     

定量组织速度成像和组织追踪对正常人左室壁运动的研究

目的应用定量组织多普勒速度成像(quantitative tissue velocity imaging,QTVI)和组织追踪法(tissue tracking,TT)分析正常人左室心肌长轴方向舒缩运动的特点,探讨QTVI和TT技术评价心肌运动的应用价值.方法获取标准心尖位左室长轴切面、两腔切面及四腔切面,分别应用QTVI和TT技术,对30例正常人左室各节段长轴方向舒缩运动的特点进行测定分析.结果正常人每个心动周期中,室壁运动速度曲线均包括收缩波(S)、快速充盈波(E)和左房收缩充盈波(A)三个主要运动波,以及等容舒张波(IR)和等容收缩波(IC).正常人心肌不同节段收缩期和舒张期运动速度呈一梯度.同一室壁从心底向心尖部,运动速度和位移逐渐降低.同一水平不同节段心肌运动速度和位移也有差别.结论正常人室壁运动存在特有的不均一性,QTVI和TT对评价局部心肌运动具有很好的应用价值,进而为诊断冠心病开辟一种新途径.     

多巴酚丁胺负荷多普勒组织超声心动图预测PTCA术后冬眠心肌功能改善的价值

目的：探讨PWDTI结合LDDSK预测PTCA术后冬眠心肌功能改善的价值。方法：采用PWDTI结合LDDSK测量36例陈旧性心梗患者(静息下观察82个室壁运动异常节段)PTCA术前1天静息下和负荷下室壁运动异常节段峰值收缩速度Vs，并计算负荷下S％增长。PTCA术后4～6周随访分析。结果：PTCA术后，46节段室壁运动改善，36节段室壁运动未改善。以S％＞35％为裁断值，PWDTI结合LDDSK预测PTCA术后室壁功能改善的敏感性86．9％、特异性86．1％、准确性86．6％、阳性预测值88．9％、阴性预测值83．8％。结论：脉冲多普勒组织成像结合多巴酚丁胺负荷超声心动图可识别冬眠心肌并准确地预测PTCA术后局部左室功能改善。     

Development of a fully quantitative approach to the interpretation of stress echocardiography using radial and longitudinal myocardial velocities.

BACKGROUND: Tissue Doppler may be used to quantify regional left ventricular function but is limited by segmental variation of longitudinal velocity from base to apex and free to septal walls. We sought to overcome this by developing a composite of longitudinal and radial velocities. METHODS AND RESULTS: We examined 82 unselected patients undergoing a standard dobutamine echocardiogram. Longitudinal velocity was obtained in the basal and mid segments of each wall using tissue Doppler in the apical views. Radial velocities were derived in the same segments using an automated border detection system and centerline method with regional chords grouped according to segment location and temporally averaged. In 25 patients at low probability of coronary disease, the pattern of regional variation in longitudinal velocity (higher in the septum) was the opposite of radial velocity (higher in the free wall) and the combination was homogeneous. In 57 patients undergoing angiography, velocity in abnormal segments was less than normal segments using longitudinal (6.0 +/- 3.6 vs 9.0 +/- 2.2 cm/s, P =.01) and radial velocity (6.0 +/- 4.0 vs 8.0 +/- 3.9 cm/s, P =.02). However, the composite velocity permitted better separation of abnormal and normal segments (13.3 +/- 5.6 vs 17.5 +/- 4.2 cm/s, P =.001). There was no significant difference between the accuracy of this quantitative approach and expert visual wall motion analysis (81% vs 84%, P =.56). CONCLUSION: Regional variation of uni-dimensional myocardial velocities necessitates site-specific normal ranges, probably because of different fiber directions. Combined analysis of longitudinal and radial velocities allows the derivation of a composite velocity, which is homogeneous in all segments and may allow better separation of normal and abnormal myocardium.     

应变率显像定量评价冠状动脉旁路移植术后左心室局部功能

目的 探讨应变率显像(SRI)技术在评价冠心病患者冠状动脉旁路移植术前后左心室局部功能变化中的应用价值.方法 对16例冠心病患者分别于冠状动脉旁路移植术前3 d、术后12 d及3个月行超声心动图检查,应用SRI技术对左室各壁基底段和中间段的局部心肌功能进行定量分析,共分析192个节段.根据术前二维超声心动图室壁运动情况将心肌节段分为运动正常组(152个节段)和运动异常组(40个节段).结果 术前运动正常组收缩期心肌峰值应变率(SRs)和舒张早期心肌峰值应变率(SRe)与运动异常组相比差异无统计学意义(P>0.05).运动异常组术后3个月的房缩期心肌峰值应变率(SRa)较术前3 d增高(P<0.05).运动正常组术后3个月与术前3 d相比,SRs、SRa及SRe均增高(分别P<0.05和0.01),术后3个月与术后12 d相比,SRs增高(P<0.05).结论 应用SRI技术能定量评价冠状动脉旁路移植术前后左室局部心肌功能的改变.     

Automated interpretation of regional left ventricular wall motion from cardiac magnetic resonance images.

Magnetic resonance (MR) diagnosis of regional left ventricular (LV) dysfunction relies on visual interpretation of cine images that suffers from wide inter-observer variability, especially when performed by readers not specifically trained in the assessment of LV wall motion. Quantitative analysis tools, though widely available, are rarely used because they provide large amounts of detailed information, the interpretation of which requires additional time-consuming processing. We tested the feasibility of fast automated interpretation of regional LV function using computer analysis of this wall motion information. METHODS: Dynamic, ECG-gated, steady-state free precession short-axis images were obtained in 6-10 slices in 28 subjects (10 normal volunteers; 18 patients). Images were reviewed by an expert cardiologist who provided "gold standard" grades (normal, abnormal) for regional wall motion and, independently, by four radiologists. Same images were then analyzed using custom software. Regional fractional area changes computed in normal volunteers were used to obtain the optimal segment- and slice-specific threshold values for automated classification of regional wall motion for each patient. The levels of agreement with the "gold standard" grades were compared between the radiologists and the automated interpretation. RESULTS: While the visual interpretation required 2-5 minute per patient, the automated interpretation required < 1 sec, after endocardial border detection was complete. The automated interpretation resulted in higher sensitivity, specificity, and accuracy (84%, 77%, 79%, respectively) than the radiologists' grades (80%, 76%, 77%, respectively) and eliminated the high interobserver variability. CONCLUSION: Once the endocardial boundaries are defined, computer analysis of the regional wall motion information allows accurate, fully automated, immediate, objective and experience-independent interpretation of regional LV function.     

彩色室壁运动技术评价冠心病节段性室壁运动的临床研究

目的：探讨彩色室壁运动技术（ＣＫ）在定量评价室壁节段性运动异常（ＲＷＭＡ）方面的应用价值。方法：分别以常规二维超声（２ＤＥ）及Ｃ技术对７例冠心病患者及３０例正常人乳头肌水平左室短轴切面室壁节段性运动进行评价。结果：正常组未发现节段性室壁运动异常,收缩期心内膜位移连续均匀,正常节段位移时间范围为２８０～３６０ｍｓ。平均值３２０ｍｓ,位移幅度范围为７～１２ｍｍ,平均值９．５ｍｍ,缺血组织２４例患者出现     

Automatic Measurements of Mitral Annular Plane Systolic Excursion and Velocities to Detect Left Ventricular Dysfunction

The purpose of the study described here was to evaluate an automatic algorithm for detection of left ventricular dysfunction, based on measurements of mitral annular motion indices from color tissue Doppler apical four-chamber recordings. Two hundred twenty-one patients, among whom 49 had systolic and 11 had diastolic dysfunction, were included. Echocardiographic evaluation by cardiologists was the reference. Twenty patients were also examined by medical students. The ability of the indices to detect systolic and diastolic dysfunction were compared in receiver operating characteristic analyses, and the agreement between automatic and reference measurements was evaluated. Mitral annular plane systolic excursion ≤10?mm detected left ventricular dysfunction with 82% specificity, 76% specificity, 56% positive predictive value and 92% negative predictive value. The automatic measurements acquired from expert recordings better agreed better with the reference than those acquired from student recordings. We conclude that automatic measurements of systolic mitral annular motion indices can be helpful in detection of left ventricular dysfunction.     

星形算法对心尖四腔切面左心室内膜全自动勾画的初步研究

目的初步测试一种叫做星形算法的全自动超声边界探测方法的实用价值.方法星形算法采用了从左心室腔内向四周作放射形探测的心内膜探测方法,并且运用了以平均相邻距离和局部平均边界灰度为构件的代价函数来勾画边界.结果本文用八组带有各种质量问题的舒张末期和收缩末期心尖四腔切面图像对星形算法进行测试,与手工勾画的心内膜相比,星形算法勾画边界的平均半径误差率为12.90%,所围平均面积误差率为10.93%.结论星形算法能够在临床条件下实现心内膜的全自动勾画.