Bos L J, Piek J J, Spaan J A
Department of Cardiology, Academic Medical Centre of Amsterdam, The Netherlands.
Ultrasound Med Biol. 1996;22(2):217-27. doi: 10.1016/0301-5629(95)02032-2.
Literature states that the inability of myocardial contrast echocardiography to assess differences in flow between regions could be related to myocardial shadowing. In this study, we evaluate this effect on the time-intensity curves. In a perfusion phantom, shadowing was induced by high concentrations of a contrast agent (approximately 1 x 10(8) bubbles/mL), and evaluated for different flows (50-270 mL/min). The high concentration resulted in an increase of the video-intensity in regions of interest close to the transducer (2 mm) and a marked reduction in remote areas (20 mm). The peak intensity of the time-intensity curves did not correlate with flow (range r = 0.1, 0.37), while the inverse area under the curve correlated strongly (r = 0.98). The inverse curve width and the decay after peak intensity also correlated excellently with flow (r = 0.99 and range r = 0.97, 0.99). We opt for the decay as transmural flow indicator using contrast echocardiography, since this parameter is least affected by shadowing.
文献表明，心肌对比超声心动图无法评估各区域之间血流差异可能与心肌声影有关。在本研究中，我们评估了这种效应对时间-强度曲线的影响。在一个灌注模型中，通过高浓度的造影剂（约1×10⁸个气泡/毫升）诱导声影，并针对不同的血流速度（50 - 270毫升/分钟）进行评估。高浓度导致靠近换能器（2毫米）的感兴趣区域视频强度增加，而在远处区域（20毫米）则显著降低。时间-强度曲线的峰值强度与血流速度不相关（相关系数r范围为0.1, 0.37），而曲线下面积的倒数与血流速度高度相关（r = 0.98）。曲线宽度的倒数以及峰值强度后的衰减也与血流速度高度相关（r = 0.99，相关系数r范围为0.97, 0.99）。我们选择衰减作为使用对比超声心动图的跨壁血流指标，因为该参数受声影影响最小。
