Leong-Poi H, Le E, Rim S J, Sakuma T, Kaul S, Wei K
Cardiac Imaging Center, and the Cardiovascular Division, University of Virginia School of Medicine, Charlottesville, USA.
J Am Soc Echocardiogr. 2001 Dec;14(12):1173-82. doi: 10.1067/mje.2001.115982.
Although regional myocardial perfusion can be currently quantified with myocardial contrast echocardiography (MCE) by using intermittent harmonic imaging (IHI), the method is tedious and time-consuming in the clinical setting. We hypothesized that regional myocardial perfusion can be quantified and the severity of coronary stenosis determined during hyperemia with MCE using real-time imaging (RTI) where microbubbles are not destroyed. Six open-chest dogs were studied during maximal hyperemia induced by adenosine in the absence or presence of coronary stenoses varying from mild to severe. Myocardial blood flow (MBF) was measured at each stage by using radiolabeled microspheres. MCE was performed using both IHI and RTI. Data for the latter were acquired in both end-systole and end-diastole. No differences were found between myocardial flow velocity (MFV) derived from IHI and RTI when end-systolic frames were used for the latter. MFV was consistently higher for RTI (P <.01) when end-diastolic frames were used. A linear relation was noted between MFV and radiolabeled microsphere-derived MBF ratios from the stenosed and the normal beds when end-systolic frames were used for RTI (r = 0.78, P <.001), whereas no relation was found when end-diastolic frames were used (r = 0.08, P =.78). The scatter for assessing MBF (A.beta) was minimal for IHI and RTI (9%-10%) with end-systolic frames, whereas that for RTI with end-diastolic frames was large (30%). Furthermore the correlation with radiolabeled microsphere-derived MBF was significantly (P <.01) weaker with RTI when end-diastolic frames were used (r = 0.53) than when end-systolic frames (r = 0.94) or IHI was used (r = 0.99). Data acquisition for IHI was 10 minutes, whereas it was 8 seconds for RTI. Thus, RTI can be used to quantify regional myocardial perfusion and stenosis severity during MCE. Only end-systolic frames, however, provide accurate data. RTI offers a rapid and easy means of assessing regional myocardial perfusion with MCE.
尽管目前可通过使用间歇谐波成像（IHI）的心肌对比超声心动图（MCE）对局部心肌灌注进行定量分析，但在临床环境中该方法既繁琐又耗时。我们推测，使用实时成像（RTI）且微泡不被破坏的情况下，在充血期可通过MCE对局部心肌灌注进行定量分析并确定冠状动脉狭窄的严重程度。在6只开胸犬身上进行了研究，这些犬在无冠状动脉狭窄或存在从轻度到重度不等的冠状动脉狭窄的情况下，由腺苷诱导产生最大充血。在每个阶段使用放射性标记微球测量心肌血流量（MBF）。同时使用IHI和RTI进行MCE。RTI的数据在收缩末期和舒张末期均有采集。当将收缩末期图像用于RTI时，从IHI和RTI得出的心肌流速（MFV）之间未发现差异。当使用舒张末期图像时，RTI的MFV始终较高（P <.01）。当将收缩末期图像用于RTI时，狭窄和正常心肌床的MFV与放射性标记微球衍生的MBF比值之间存在线性关系（r = 0.78，P <.001），而当使用舒张末期图像时未发现相关性（r = 0.08，P =.78）。对于收缩末期图像，IHI和RTI评估MBF（A.beta）的离散度最小（9%-10%），而对于舒张末期图像的RTI，离散度较大（30%）。此外，当使用舒张末期图像时（r = 0.53），与放射性标记微球衍生的MBF的相关性相比使用收缩末期图像（r = 0.94）或IHI（r = 0.99）时，RTI明显较弱（P <.01）。IHI的数据采集时间为10分钟，而RTI为8秒。因此，RTI可用于在MCE期间对局部心肌灌注和狭窄严重程度进行定量分析。然而，只有收缩末期图像能提供准确数据。RTI为使用MCE评估局部心肌灌注提供了一种快速简便的方法。
