Bos L J, Piek J J, Spaan J A
Department of Cardiology, Academic Medical Centre of Amsterdam, Netherlands.
Ultrasound Med Biol. 1995;21(9):1211-8. doi: 10.1016/0301-5629(95)02015-2.
Background subtraction for contrast echocardiography is considered a prerequisite for an appropriate assessment of flow from the time-intensity curves. We evaluated the influence of different background intensities on flow determinations with contrast echocardiography. Experiments were performed with a mixing chamber as a phantom for myocardial perfusion. Three regions of interest with different background intensities but equal flow were examined. Time-intensity curves were obtained and, after background subtraction, a number of curve parameters were determined: peak intensity, area under the curve, curve width and decay after peak intensity. The values of these parameters differed significantly between a region with a low and a region with a high background. In addition, a model is presented to describe these findings. It is concluded that subtraction of the background intensity from a time-intensity curve induces errors that make a quantitative interpretation of the curves ambiguous. These drawbacks are avoided if regions of interest with equal background intensities are compared.
对比超声心动图中的背景减法被认为是从时间-强度曲线适当评估血流的先决条件。我们评估了不同背景强度对对比超声心动图血流测定的影响。实验使用混合室作为心肌灌注模型进行。检查了三个具有不同背景强度但血流相同的感兴趣区域。获取时间-强度曲线，并在背景减法后确定一些曲线参数：峰值强度、曲线下面积、曲线宽度和峰值强度后的衰减。这些参数的值在低背景区域和高背景区域之间存在显著差异。此外，还提出了一个模型来描述这些发现。得出的结论是，从时间-强度曲线中减去背景强度会引入误差，使曲线的定量解释变得模糊。如果比较具有相同背景强度的感兴趣区域，这些缺点是可以避免的。
