Cardiovascular Division, Washington University School of Medicine, Campus Box 8215, 4320 Forest Park Avenue, St. Louis, Missouri 63108, USA.
J Acoust Soc Am. 2011 Jun;129(6):3756-67. doi: 10.1121/1.3578459.
In several investigations of molecular imaging of angiogenic neovasculature using a targeted contrast agent, Renyi entropy [I(f)(r)] and a limiting form of Renyi entropy (I(f,∞)) exhibited significantly more sensitivity to subtle changes in scattering architecture than energy-based methods. Many of these studies required the fitting of a cubic spline to backscattered waveforms prior to calculation of entropy [either I(f)(r) or I(f,∞)]. In this study, it is shown that the robustness of I(f,∞) may be improved by using a smoothing spline. Results are presented showing the impact of different smoothing parameters. In addition, if smoothing is preceded by low-pass filtering of the waveforms, further improvements may be obtained.
在使用靶向对比剂对血管生成新生血管进行分子成像的几项研究中，Renyi 熵 [I(f)(r)] 和 Renyi 熵的一种极限形式 (I(f,∞)) 比基于能量的方法对散射结构的细微变化表现出更高的敏感性。这些研究中的许多研究都需要在计算熵[I(f)(r)或 I(f,∞)]之前对背散射波形进行三次样条拟合。在本研究中，表明通过使用平滑样条可以提高 I(f,∞)的稳健性。结果表明了不同平滑参数的影响。此外，如果在对波形进行低通滤波后进行平滑处理，则可以获得进一步的改进。
