Ultraharmonic myocardial contrast imaging: in vivo experimental and clinical data from a novel technique.

Myocardial contrast echocardiography (MCE) with high-mechanical-index (MI), triggered harmonic imaging is the best-established technique to date for the assessment of myocardial perfusion. A high signal-to-noise ratio, which is significantly influenced by precontrast tissue signals, is an important prerequisite. Our goal was to evaluate the efficacy of ultraharmonic MCE, a technique that rejects tissue signals by receiving signals beyond the second but below the third harmonic. Imaging was performed in 6 closed-chest dogs and in 15 healthy volunteers (11 of whom also had dipyridamole stress). Analyses of videointensity (VI) confirmed uniformly low precontrast tissue VI, a significant increase of postcontrast VI (before and after dipyridamole), and a significant decrease in VI after microbubble destruction. We conclude that ultraharmonic MCE produces low precontrast tissue signals, thus optimizing postcontrast myocardial opacification, and exhibits efficient microbubble destruction with use of multiple-frame triggering. Thus this new technique opens up a new possibility of further optimizing coronary microcirculation imaging with microbubbles.     

Optimum trigger timing for intermittent mode in intravenous myocardial contrast echocardiography

Background Although the intermittent mode is necessary for myocardial opacification in intravenous myocardial contrast echocardiography (MCE), the effect of EGG trigger timing, on good myocardial opacification without production of artifacts, is not clear. Method MCE was performed on six closed-chest dogs by injecting FS 69 (0.1 ml) intravenously using an Acuson Sequoia 512 ultrasound system with intermittent harmonic imaging (1.75/3.5 MHz) in the short-axis view. Myocardial opacification and acoustic shadow were evaluated from a video tape recording triggered at every end-systole or end-diastole phase. Peak video intensity of four quadrant regions and extent of the acoustic shadow expressed as the incident angle viewed from the center of the left ventricular cavity were measured. Results The angle of acoustic shadow was significantly larger in the image triggered at end-diastole than in the image triggered at end-systole. However, trigger timing did not affect myocardial opacification in either region. Conclusion Trigger timing should be set at end-systole to minimize acoustic shadowing.     

Quantification of myocardial blood flow and assessment of its transmural distribution with real-time power modulation myocardial contrast echocardiography.

BACKGROUND: The purpose of this study was to examine the ability of real-time myocardial contrast echocardiography (MCE) with power modulation to quantitate myocardial blood flow (MBF) and to assess its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses. METHODS AND RESULTS: MBF was measured in 12 dogs instrumented with a cuff occluder around the left anterior descending coronary artery at rest, during partial coronary stenosis (during infusion of adenosine), and during coronary occlusion. The MCE-derived rate of microbubble velocity, beta, and myocardial blood volume, A, were obtained by curve fitting of videointensity versus time plots, after the transient destruction of microbubbles by high-energy ultrasound. The data were compared with MBF measured with radiolabeled microspheres. Significant correlations were found between radiolabeled microsphere-derived MBF and both beta (r = 0.93) and the product of A x beta (r = 0.91). MCE beta reserve also correlated well with microsphere-derived flow reserve. Comparing endocardial/epicardial MCE ratios and microsphere-derived MBF ratios, significant correlation was also found between endomicropsheres/epimicrospheres MBF ratio and both endo/epi beta (r = 0.90) and endo/epi A x beta (r = 0.88). CONCLUSIONS: Real-time power modulation MCE allows for an accurate quantification of MBF and of its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses.     

Early impairment of myocardial blood flow reserve in men with essential hypertension: a quantitative myocardial contrast echocardiography study.

OBJECTIVE: Aims of this study were to: (1) demonstrate whether quantitative myocardial contrast echocardiography could detect an index of myocardial blood flow reserve through the analysis of refilling curves generated by microbubble transit into myocardium both at rest and after vasodilatation induced by dipyridamole; and (2) explore with this method myocardial microcirculatory function in two different models (ie, patients with essential hypertension and control subjects). METHODS: Two groups of strictly age-matched men were studied (case-control study): 12 patients who were adults (28.2 +/- 0.2 years) and asymptomatic with never-treated essential hypertension, a mild degree of left ventricular hypertrophy, and normal left ventricular function; and 12 control subjects. Quantitative myocardial contrast echocardiography was performed in all study participants. We used second-generation ultrasound microbubbles as echocardiography contrast agent. Real-time color-coded power modulation was performed with a phased-array system interfaced to a S3 transducer (1.3-3.6 MHz). RESULTS: In control subjects there was little increase in myocardial blood volume (30%) between basal and hyperemic status (P <.05); in patients with hypertension this parameter increased by 22% (P <.05). Myocardial blood velocity increased after dipyridamole by 270% in control subjects (P <.01), whereas for patients with hypertension this parameter increased only by 150% (P <.02). The index of myocardial blood flow reserve was significantly lower for patients with hypertension than in control subjects (3.3 +/- 0.3 vs 4.4 +/- 0.3, respectively; P <.01). CONCLUSION: Results of our study documented that myocardial microcirculation in young adult patients with hypertension showed an early impairment in the vasodilatation capacity of the resistance arterioles under dipyridamole-induced hyperemia, as demonstrated by a reduction of myocardial blood flow reserve. Myocardial blood velocity increased after dipyridamole induction in control subjects, whereas patients with hypertension showed a significantly lesser increase. Myocardial blood flow reserve was significantly lower for patients with hypertension because of an early impairment in vasodilatation capacity of resistance arterioles under dipyridamole-induced hyperemia.     

Quantification of transmural gradient of blood flow in myocardial ischemia with real-time myocardial contrast echocardiography and dipyridamole stress test

Transmural redistribution of myocardial blood flow (MBF) is the earliest sign of myocardial ischemia. We aimed to evaluate the ability of real-time myocardial contrast echocardiography (MCE) combined with dipyridamole stress to quantify the transmural gradient of MBF during graded coronary stenosis. Real-time MCE was performed in 14 open-chest dogs at seven experimental stages: baseline; hyperemia induced by 6-min infusion of dipyridamole; 50%, 75% and 90% reduction of hyperemic flow after constriction in each stage for 10 min; reperfusion for 10 min; and subtotal occlusion of the left anterior descending coronary artery (LAD) for 90 min. We obtained MCE perfusion parameters from subendocardial (A-endo, beta-endo and A x beta-endo) and subepicardial (A-epi, beta-epi and A x beta-epi) layers of the ventricular septum and calculated their transmural gradients (A-EER, beta-EER and A x beta-EER) and systolic wall thickening (SWT). The sensitivity and specificity of each parameter for predicting 75% reduction of hyperemic flow, which was defined as mild myocardial ischemia, were derived by receiver operating characteristic (ROC) curve analysis. No transmural gradients were found at baseline; during maximal hyperemia and 50% reduction of hyperemic flow. beta-endo, A x beta-endo, beta-EER and A x beta-EER decreased significantly when the hyperemic flow was reduced by 75% or more. In contrast, SWT remained unchanged until the hyperemic flow was reduced by 90%. Among all parameters measured, beta-EER and A x beta-EER had the highest and SWT the lowest sensitivity and specificity in predicting mild myocardial ischemia. In conclusion, real-time MCE combined with dipyridamole stress allows for quantification of the transmural gradient of MBF. beta-EER and A x beta-EER are more sensitive than SWT and other MCE parameters in detecting mild myocardial ischemia.     

实时心肌超声造影评价X综合征患者心肌冠状动脉血流储备

目的 应用实时心肌超声造影评价X综合征患者心肌冠脉血流储备.方法 选择X综合征患者10例,对照组7例,应用超声造影剂SonoVue进行实时心肌超卢造影检查,分别测定静息状态和腺苷负荷后造影剂微泡达到峰值的最大声强度(A),再充盈平均速度(β)及A×β,并测定冠脉血流储备(负荷前后A×β的比值).结果 X综合征患者静息时A与对照组相比差异无统计学意义(P>0.05),β值和A×β值低于对照组(P<0.01),X综合征患者冠状动脉血流储备值明显低于对照组,差异有统计学意义(P<0.01).结论 X综合征患者心肌微血管功能受损,实时心肌超声造影可评价X综合征患者心肌冠脉血流储备.     

双嘧达莫与多巴酚丁胺负荷心肌超声造影探测冠脉狭窄的对比研究

目的对比双嘧达莫和多巴酚丁胺负荷心肌超声造影(MCE)探测静息状态下无心肌血流限制性冠脉狭窄的能力.方法用放置"水膨胀”式缩窄器于冠脉主干近端的方法,建立15只慢性多支冠脉狭窄闭胸犬模型.术后7～10d进行静息、双嘧达莫和多巴酚丁胺的小剂量微泡弹丸式注射法MCE,并同步用放射性标记微球测量心肌血流(MBF).以MBF储备≥3为正常和＜3为异常供血区.结果两种药物引起MBF增加,在正常和异常供血区均相近.两种药物负荷时,MCE示异常供血区灌注缺损的范围和程度相同.两种药物作用下异常供血区的峰值声强度(VI)均较正常供血区低(P＜0.05),异常和正常供血区峰值VI比值非常接近;且双嘧达莫和多巴酚丁胺的峰值VI比值均与相应的MBF比值呈良好的线性正相关(r=0.90和0.87,P＜0.0001).结论双嘧达莫和多巴酚丁胺负荷MCE探测冠脉狭窄的能力相近.因此,两者均可用于慢性冠脉狭窄的诊断.     

Myocardial blood flow measurements in rats with simple pulsing contrast echocardiography

Relationship between contrast intensity and ultrasound (US) pulsing interval has been utilized to quantify myocardial blood flow (MBF) during myocardial contrast echocardiography (MCE). We tested if an MCE method employing a simple pulsing sequence during intravenous contrast infusion has the ability to quantify MBF in rats. We performed MCE in 17 rats using a 5- to 12-MHz broadband transducer during microbubble infusion via the femoral vein. Acoustic density (AD) from the anterior wall of the left ventricle imaged in the short axis plane was plotted against the frame number after shortening the pulsing interval (PI) from 1:20 to 1:1 end-systolic ECG gating. The relation between AD and frame number was fitted to a decay function. The rate of the AD decay was decreased during dipyridamole infusion, but was increased by causing coronary stenosis. The AD during long PI imaging remained unchanged during the interventions. Estimated MBF by MCE after correction by heart rate exhibited a close correlation (r = 0.83) with the present "gold standard" of colored microsphere-derived MBF. Thus, the decay rate of the contrast intensity obtained with the high-frequency transducer after abrupt shortening of PI during intravenous microbubble infusion may provide for noninvasive measurement of MBF in rats.     

利声显经静脉心肌声学造影评价心肌梗死后患者的心肌灌注

目的 心肌造影超声心动图（MCE）采用触发谐频能量多普勒显像模式并用静脉持续输液利声显,观察心肌梗死后患者的心肌灌注情况,方法,使用谐频频率1．8－3．6MHZ的能量多普勒模式,于心电图T波终末处,按1：4心动周期进行触发,利声显浓度为300mg/ml,采用微量输液泵将所配心肌造影剂于患者左肘静脉内持续输注4 min(2ml/min),25例心肌梗死后患者的血压和心率变化并对心肌灌注情况进行半定量分析。结果 （1）MCE前后,患者血压和心率改变无明显差异;（2）触发谐频能量多普勒显像模式并用静脉持续输液min的心肌显影效果,而后方衰减可以避免。结论 触发谐频能量多普显像并用静脉持续输注利声显,可以产生较好的心肌灌注显像效果。     

Measurement of myocardial blood flow velocity reserve with myocardial contrast echocardiography in patients with suspected coronary artery disease: comparison with quantitative gated Technetium 99m sestamibi single photon emission computed tomography.

BACKGROUND: The ability of high and low mechanical index (MI) imaging methods during myocardial contrast echocardiography (MCE) to assess the physiologic significance of coronary stenoses were compared with technetium 99m sestamibi single photon emission computed tomography (SPECT) in patients. METHODS: Intermittent ultraharmonic imaging (high MI) and power modulation angio (low MI) were performed during continuous infusions of the echo-enhancing contrast agent, Optison, at rest and after dipyridamole stress in 39 patients. Technetium 99m sestamibi SPECT was performed simultaneously. Images from the 3 apical windows were divided into 6 walls. Myocardial blood flow (MBF) velocity and MBF velocity reserve were quantified from pulsing interval versus acoustic intensity MCE curves in each wall using postprocessed images. RESULTS: Approximately 25% of the myocardial walls could not be analyzed from MCE because of artifacts. MBF velocity and MBF derived from both MCE methods increased significantly after dipyridamole in healthy patients (n = 143 and 129 walls for high and low MI, respectively), compared with those with either reversible (n = 11 and 10 walls for high and low MI, respectively) or fixed defects (n = 18 and 14 walls for high and low MI, respectively) on SPECT. Consequently, MBF velocity and MBF reserve were significantly greater for patients with normal perfusion. Receiver operator characteristic curves obtained for MBF velocity reserve provided a sensitivity and specificity of 82% and 87%, respectively, for high MI; versus 64% and 96%, respectively, for low MI imaging after uninterpretable images were excluded from analysis. CONCLUSIONS: Both high and low MI MCE imaging techniques can be used to determine the presence of perfusion defects as identified by technetium 99m sestamibi SPECT. Low MI imaging methods have a number of drawbacks that limit its sensitivity compared with high MI techniques.     

心肌造影超声心动图对糖尿病大鼠心肌微循环的评价

目的 研究心肌造影超声心动图(MCE)技术结合潘生丁负荷试验是否能够早期检测糖尿病(DM)大鼠左室心肌微循环的功能障碍.方法 雄性SD大鼠18只,腹腔注射链脲菌素复制DM模型,另12只体质量匹配的雄性SD大鼠腹腔注射生理盐水作为对照.分别在静息状态和潘生丁负荷后,对两组大鼠(12周)乳头肌水平左室短轴行MCE检查,测定各室壁感兴趣区域峰值声学强度(PI)、造影剂灌注速率(β)及声学强度达峰时间(TTP)等指标,计算心肌血流量(MBF)和心肌血流储备(MFR).MCE检查完毕后,对心肌组织分别行~(99m)Tc-MIBI核素摄取量及毛细血管密度测定.结果 无论静息状态还是负荷后,同组大鼠后壁的MBF较前壁、侧壁和室间隔的MBF显著减低(P<0.05);取前壁心肌进行组间比较,静息状态和负荷后,DM组的PI、MBF和MFR均较对照组显著减低(P<0.05).潘生丁负荷后,DM组β也较对照组显著减低,TTP显著延长(P<0.05).DM组各室壁的核素摄取量和毛细血管密度均显著减低(P<0.05).结论 MCE检测的PI、β、TTP、MBF及MFR等指标可以敏感地检测出DM早期的心肌微循环功能障碍.     

Real-time myocardial contrast echocardiography for pharmacologic stress testing: is quantitative estimation of myocardial blood flow reserve necessary?

BACKGROUND: Little is known about the diagnostic accuracy of quantitative real-time myocardial contrast echocardiography (MCE) as an adjunct to stress testing. This study was performed to evaluate the agreement between MCE and technetium 99m-sestamibi single photon emission computed tomography (SPECT) for detection of perfusion defects and to investigate whether quantitative assessment of myocardial perfusion can increase the diagnostic value of MCE. METHODS: MCE was performed at rest and during peak adenosine stress in 50 unselected patients undergoing SPECT imaging. Concordance between the 2 methods was assessed using kappa statistics. MCE images were analyzed quantitatively, measuring peak intensity (A) and maximal rise of signal intensity (beta). Myocardial blood flow reserve was estimated by calculating the ratios of A(adenosine)/A(baseline) (A reserve), beta(adenosine)/beta(baseline) (beta reserve), and A x beta(adenosine)/A x beta(baseline) (A x beta reserve). RESULTS: Visual analysis of MCE agreed well with SPECT (kappa = 0.67) with sensitivity of 64%, specificity of 97%, and overall accuracy of 87%. Quantitative analysis showed that peak signal intensity A significantly increased under adenosine stress in SPECT-normal segments (2.6 +/- 1.9 vs 3.0 +/- 1.6 dB, P <.0001), tendencially decreased in reversible (3.0 +/- 2.0 vs 2.4 +/- 1.2 dB, P =.07) and remained unchanged in fixed (0.9 +/- 0.9 vs 0.8 +/- 0.9 dB) defects. beta Increased markedly under adenosine in normal segments (0.4 +/- 0.4 vs 1.4 +/- 1.3, P <.0001) but not in segments with reversible or fixed defects. Receiver operating characteristic showed that beta reserve and A x beta reserve, but not A reserve, are sensitive parameters for detecting perfusion defects with areas under the curve of 0.84, 0.85, and 0.61, respectively. Cut-off values of 1.9 and 2.3, respectively, for beta and A x beta reserve yielded sensitivity rates of 79% and 80%, specificity rates of 75% and 78%, and overall accuracy rates of 76% and 79%, respectively. CONCLUSION: Quantitative estimation of myocardial blood flow reserve by MCE parameters corresponds to the evaluation of myocardial perfusion by nuclear imaging and can increase the sensitivity but not the overall accuracy of contrast echocardiography.     

Quantitative parameters of myocardial perfusion with contrast echocardiography in human beings: Influence of triggering mode

To facilitate quantitation of myocardial contrast echocardiography (MCE) in human beings, dual- or triple-triggered flash imaging has been advocated. However, the effect of this modality on quantitative blood-flow parameters of MCE is not known. Accordingly, MCE was quantitated in 71 myocardial regions of 22 patients (age: 57 +/- 16 years) during continuous infusion of Optison (12-18 mL/h). Two sets of images with end-systolic gating (1:1, 1:2, 1:3, 1:4, 1:6, and 1:8) from the apical 4-chamber view were acquired: single and dual triggering for the first 15 patients; and single and triple triggering for the other 7 patients. During gated imaging, MCE of the first, second, and third frame were quantitated. Curves of intensity versus pulsing intervals were fitted to an exponential function: y = A (1-e(-betat)). Where beta is myocardial blood velocity or the rate of rise of myocardial contrast intensity (MCI), and A is myocardial blood volume or the plateau of MCI reached. Continuous imaging, and the second and third frame in 1:1 gating only, provided similar intensity to precontrast imaging. Beyond 1:1 gating, MCI of the second frame in dual triggering mode gradually increased with incremental pulsing interval. This was still present but less pronounced in triple triggering. During dual and triple triggering, a lower beta was observed compared with single triggering. Application of image subtraction with the flash procedure further decreased beta, A, and the A(*)beta product, a quantitative parameter of blood flow by MCE. Thus, flash subtraction imaging alters the quantitative parameters of myocardial blood velocity and flow derived from MCE. Continuous imaging, and the second or third frame in flash imaging at 1:1 gating only, result in MCI similar to precontrast imaging and can be used for background subtraction to quantitate MCE parameters.     

心肌造影检测冠状动脉微循环内皮损伤的初步应用研究

目的：探讨心肌超声造影（Myocardial contrast echocardiography, MCE）在检测冠心病早期冠脉微循环内皮损伤中的应用价值。资料与方法：选择冠状动脉造影（Coronary angiography, CAG）检查结果正常的患者20例为冠心病高危人群组（第2组）,另选年龄匹配的健康志愿者20例作对照组（第1组）行“声诺维”心肌造影。造影后进行4次闪烁成像,分析两组闪烁显像后心肌血流再灌注充盈曲线,获得再充盈峰值强度（PI）、达峰值强度时间（TP）以及心肌内微泡持续显影时间（T）并作定量分析。结果：第2组4次flash后的峰值强度均低于对照组（P<0.05）,达峰值强度时间（TP）以及心肌内微泡持续显影时间均明显大于对照组（P<0.05）。结论：MCE通过定量评价心肌微循环灌注可达到检测冠状动脉微循环内皮功能损伤的目的。     

Adenosine myocardial contrast echo in intermediate severity coronary stenoses: a prospective two-center study

Background We sought to evaluate the role of adenosine myocardial contrast echocardiography (MCE) for the determination of functional relevance of coronary stenoses with intermediate angiographic severity and compared the results to single photon imaging (SPECT). We hypothezised that sole assessment of myocardial blood volume changes during adenosine on MCE would indicate functional stensosis relevance when accompanied by increased myocardial oxygen consumption (MVO2). Methods Fifty-seven patients with ≥1 coronary stenosis underwent adenosine MCE (ultraharmonic imaging) and exercise SPECT. On MCE, myocardial blood volume was assessed and constant or increased myocardial opacification during adenosine coupled with increased MVO2 was defined as normal and decreased opacification as abnormal. Results Rate–pressure product significantly increased during adenosine in all patients due to reflex tachycardia following mild hypotension, indicative of increased MVO2. Concordance between MCE and SPECT for the detection of reversible myocardial perfusion defects was 89% (κ = 0.83). Comparison of regions between rest and during adenosine as opposed to comparison to remote regions of the same stage was important for accurate assessment because concordance betweenn MCE and SPECT was less on separate assessment at rest (73%, κ = 0.40) compared to stress (91%, κ = 0.81, P < 0.05) mainly due to territories scored normal on SPECT and abnormal on MCE. Conclusions Assessment of myocardial blood volume changes during adenosine using MCE can be used for the determination of the functional relevance of coronary stenoses of intermediate angiographic severity if MVO2 is increased during adenosine.     

潘生丁心肌声学造影估价冠脉储备的实验研究

将８条犬左旋支冠脉（ＬＣＸ）临床缩窄，于主动脉根部快速注入声振７６％复方泛影葡胺行心肌声学造影（ＭＣＥ），并结合潘生丁试验，探讨播生丁ＭＣＥ定量指标估价冠脉储备的价值。结果提示：潘生丁试验后ＬＣＸ血流量及后壁峰值呈下降趋势，而前壁峰值则呈上升趋势（Ｐ＞０．０５）；前、后壁潘生丁试验后与试验前峰值比间有显著差异；潘生丁试验后与试验前ＬＣＸ血流量比与后壁峰值比间无显著差异，两者间相关系数为０．６５。结论：ＭＣＥ潘生丁试验后与试验前峰值比能作为一项估价冠脉储备的指标。     

Automated, nonrigid alignment of clinical myocardial contrast echocardiography image sequences: comparison with manual alignment

Analysis of myocardial contrast echocardiography (MCE) images is currently done by manual techniques. The development of computationally efficient methods for aligning images provides an important first step toward the automation of MCE analysis. This is challenging because a nonrigid transformation correction is required. In this paper, we evaluate a state-of-the-art nonrigid alignment method on clinical MCE image sequences (n = 58) acquired on patients during rest and dipyridamole stress, using both B-mode intermittent ultraharmonic (IUH) imaging and real-time myocardial perfusion imaging (RTMPI). Using manual alignment as the reference, we show quantitatively that the automated method aligns images as well as a human observer. However, the new method is faster and more reliable than manual alignment and removes the need for an experienced physician to perform it. The automated technique can be used for quick poststudy off-line analysis and has the potential to be incorporated into an ultrasound machine.     

心肌超声造影在肥厚型梗阻性心肌病室间隔心肌化学消融术中的价值

目的探讨选择性靶血管心肌超声造影在肥厚型梗阻性心肌病室间隔心肌化学消融术中选择靶血管、判断消融范围、防止并发症中的作用。方法肥厚型梗阻性心肌病37例。室间隔心肌化学消融术中向拟定的靶血管远端注人心肌超声造影剂后即刻和注入无水酒精后5min，超声记录心尖四腔观、胸骨旁左室长轴观、左室短轴观，观察造影剂显影范围、比较造影剂显影范围和无水酒精显影范围。结果37例患者中2例因冠状动脉血流显像技术显示无合适血管以供消融，而放弃心肌超声造影及消融治疗．2例因冠状动脉造影显示冠状动脉分布细小弥漫而放弃治疗，未行心肌超声造影。33例行心肌超声造影的患者，1例因左心室乳头肌显影、1例因右室调节束及右室乳头肌显影、1例因显影范围不在靶域、2例因显影范围过大放弃消融治疗。余28例均成功消融。术后即刻及术后7d，左室流出道压力阶差下降≥50％。部分病例显示无水酒精的显影范围小于心肌超声造影的显影范围。结论心肌超声造影可为肥厚型梗阻性心肌病的室间隔心肌化学消融间隔支靶血管的选择及消融范围的判断提供可靠的依据。     

触发式能量多普勒谐波成像评价犬急性心肌缺血的实验研究

目的 探讨自制的白蛋白氟碳声学造影剂对急性心肌缺血的研究价值。方法 套扎犬冠状动脉左前降支，建立急性心肌缺血模型。在套孔前后分别静脉滴注声学造影剂进行触发式能量多普勒谐波成像，评价心肌灌注结果。随后取出心脏，用0.5%伊文思蓝染色作病理对照。结果 套扎冠状动脉前，整个心肌呈环状均匀的红黄色能量显像；套扎后，前壁及部分前间隔心肌无谐波能量显像。心肌灌注缺损面积与病理染色结果差异无显著性意义。结论 静脉滴注自制的白蛋白氟碳声学造影剂通过触发式能量多普勒谐波成像能使心肌灌注显影，可用来评价急性心肌缺血。     

In Vitro, Animal, and Human Characterization of OPTISON Infusions for Myocardial Contrast Echocardiography

Traditionally, performing myocardial contrast echocardiography with OPTISON required maximal bolus dosing. However, sustained and consistent opacification of the myocardium would be preferable for perfusion imaging. METHODS: Images of 5 anesthetized dogs and 6 human volunteers were obtained with a second harmonic ultrasound system during bolus administration of OPTISON and 2 infusion techniques. One infusion technique used diluted OPTISON, and the other used the buoyant properties of OPTISON microspheres by placing the contrast agent between an infusion source and the intravenous site in a vertically oriented extension line (ELT). Myocardial intensities and in vitro microsphere characteristics were analyzed to assess the consistency of microsphere delivery over time. RESULTS: In addition to providing higher myocardial opacification intensity than diluted infusions, ELT infusions provided consistent microsphere concentration, phantom enhancement, and near-peak bolus-level myocardial opacification for 7 to 15 minutes. The myocardial intensity at 3 and 5 minutes in human subjects during ELT infusions (30 mL/h; 2.5 mL) was lower (220 arbitrary units [au] and 165 au, respectively) but not significantly different (P =.3 and.1, respectively) than the peak myocardial intensity (265 au) after bolus administration. CONCLUSION: This new ELT infusion method provides an acceptable alternative to bolus administration of OPTISON for prolonged myocardial opacification.