IEEE Trans Ultrason Ferroelectr Freq Control. 2022 May;69(5):1714-1726. doi: 10.1109/TUFFC.2022.3162836. Epub 2022 Apr 27.
Phase aberration is widely considered a major source of image degradation in medical pulse-echo ultrasound. Traditionally, near-field phase aberration correction techniques are unable to account for distributed aberrations due to a spatially varying speed of sound in the medium, while most distributed aberration correction techniques require the use of point-like sources and are impractical for clinical applications where diffuse scattering is dominant. Here, we present two distributed aberration correction techniques that utilize sound speed estimates from a tomographic sound speed estimator that builds on our previous work with diffuse scattering in layered media. We first characterize the performance of our sound speed estimator and distributed aberration correction techniques in simulations where the scattering in the media is known a priori. Phantom and in vivo experiments further demonstrate the capabilities of the sound speed estimator and the aberration correction techniques. In phantom experiments, point target resolution improves from 0.58 to 0.26 and 0.27 mm, and lesion contrast improves from 17.7 to 23.5 and 25.9 dB, as a result of distributed aberration correction using the eikonal and wavefield correlation techniques, respectively.
相位误差被广泛认为是医学脉冲回波超声图像退化的主要原因。传统上，近场相位误差校正技术无法解释由于介质中声速的空间变化而导致的分布式误差，而大多数分布式误差校正技术需要使用点状源，对于以漫散射为主的临床应用来说是不切实际的。在这里，我们提出了两种利用层析声速估计器中声速估计的分布式误差校正技术，该估计器是基于我们之前在层状介质中漫散射方面的工作。我们首先在散射介质预先已知的模拟中，对我们的声速估计器和分布式误差校正技术的性能进行了描述。体模和体内实验进一步证明了声速估计器和误差校正技术的能力。在体模实验中，点目标分辨率分别提高了 0.58 毫米至 0.26 毫米和 0.27 毫米，病变对比度分别提高了 17.7 分贝至 23.5 分贝和 25.9 分贝，这是由于分别使用 eikonal 和波场相关技术进行分布式误差校正的结果。
