Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Apr;57(4):830-8. doi: 10.1109/TUFFC.2010.1488.
In color flow imaging for medical diagnosis, the inherent trade-off between frame rate and image quality may often lead to suboptimal images. Parallel receive beamforming is used to help overcome this problem, but this introduces artifacts in the images. In addition to the parallel beamforming artifacts found in B-mode imaging, we have found that a difference in curvature of transmit and receive beams gives a bias in the Doppler velocity estimates. This bias causes a discontinuity in the velocity estimates in color flow images. In this work, we have shown that interpolation of the autocorrelation estimates obtained from overlapping receive beams can reduce these artifacts significantly. Because the autocorrelation function varies quite slowly, the beams can be acquired with a considerable time difference, for instance across interleaving groups or across scan planes in a 3-D scan. We have shown that a high frame rate of color flow images can be maintained with parallel beam acquisition with minimal deterioration of the image quality.
在用于医学诊断的彩色血流成像中，帧率和图像质量之间的固有权衡往往会导致图像质量不佳。并行接收波束形成用于帮助克服这个问题，但这会在图像中引入伪影。除了在 B 模式成像中发现的并行波束形成伪影之外，我们还发现发射和接收波束的曲率差异会导致多普勒速度估计中的偏差。这种偏差会导致彩色血流图像中速度估计的不连续性。在这项工作中，我们已经表明，从重叠接收波束获得的自相关估计的插值可以显著减少这些伪影。由于自相关函数变化相当缓慢，因此可以在相当大的时间差内获取波束，例如跨交错组或在 3-D 扫描中的扫描平面之间。我们已经表明，通过并行波束采集可以以最小的图像质量恶化来维持高帧率的彩色血流图像。
