Novel quantitative assessment of myocardial perfusion by harmonic power Doppler imaging during myocardial contrast echocardiography
Novel quantitative assessment of myocardial perfusion by harmonic power Doppler imaging during myocardial contrast echocardiography
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DOI：
10.1136/hrt.2004.035857
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发表时间：
2005-01
期刊：
影响因子：
5.7
通讯作者：
S. Yamada;K. Komuro;T. Mikami;N. Kudo;H. Onozuka;K. Goto;S. Fujii;K. Yamamoto;A. Kitabatake;P. Knaapen;R. B. V. Loon;F. C. Visser
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文献类型：
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作者：
S. Yamada;K. Komuro;T. Mikami;N. Kudo;H. Onozuka;K. Goto;S. Fujii;K. Yamamoto;A. Kitabatake;P. Knaapen;R. B. V. Loon;F. C. Visser
目的：在恒定声压条件下，验证谐波能量多普勒成像（HPDI）接收信号的功率与气泡浓度成正比的假设，探讨一种新的定量方法能否克服心肌声学造影（MCE）中声场的不均匀性，识别心肌梗死引起的灌注异常。研究方法：在恒定声压条件下，体外研究了Levovist浓度与HPDI对比信号强度（CI）的关系。在11名健康受试者和25名既往心肌梗死患者中，每6个心动周期间歇性HPDI持续输注利声显进行MCE。在心尖视图中，在5个心肌节段中定量心肌CI（CImyo）。还以dB为单位测量来自邻近节段的左心室血池的CI，并从CImyo中减去（相对CI（RelCI））。结果：CI与利声显体外浓度呈对数相关，计算的信号功率与利声显体外浓度呈强线性相关。因此，X dB的CI差异指示10 X/10的微泡浓度比。在正常对照受试者中，五个节段之间的CImyo不同（p < 0.0001），较深节段的CImyo较低。然而，RelCI在节段之间没有显著差异（p = 0.083）。39个梗死节段的RelCI（平均值（SD）-18.6（2.8）dB）低于55个正常节段（平均值（SD）-15.1（1.6）dB）（p < 0.0001）。RelCI组间差异大于CImyo组。结论：新的定量方法可以克服MCE中声场不均匀性对心肌灌注的影响。RelCI代表心肌与血液微泡浓度的比值，可正确反映心肌血容量分数。
Objective: To test the hypothesis that the power of the received signal of harmonic power Doppler imaging (HPDI) is proportional to the bubble concentration under conditions of constant applied acoustic pressure, and to determine whether a new quantitative method can overcome the acoustic field inhomogeneity during myocardial contrast echocardiography (MCE) and identify perfusion abnormalities caused by myocardial infarction. Methods: The relation between Levovist concentration and contrast signal intensity (CI) of HPDI was investigated in vitro under conditions of constant acoustic pressure. MCE was performed during continuous infusion of Levovist with intermittent HPDI every sixth cardiac cycle in 11 healthy subjects and 25 patients with previous myocardial infarction. In the apical views myocardial CI (CImyo) was quantified in five myocardial segments. The CI from the left ventricular blood pool adjacent to the segment was also measured in dB and subtracted from the CImyo (relative CI (RelCI)). Results: CI had a logarithmic correlation and the calculated signal power a strong linear correlation with Levovist concentration in vitro. Thus, a difference in CI of X dB indicates a microbubble concentration ratio of 10X/10. In normal control subjects, CImyo differed between the five segments (p < 0.0001), with a lower CImyo in deeper segments. However, RelCI did not differ significantly between segments (p = 0.083). RelCI was lower (p < 0.0001) in the 39 infarct segments (mean (SD) −18.6 (2.8) dB) than in the 55 normal segments (mean (SD) −15.1 (1.6) dB). RelCI differed more than CImyo between groups. Conclusions: The new quantitative method described can overcome the acoustic field inhomogeneity in evaluation of myocardial perfusion during MCE. RelCI represents the ratio of myocardium to blood microbubble concentrations and may correctly reflect myocardial blood volume fraction.