IEEE Trans Ultrason Ferroelectr Freq Control. 2017 Jun;64(6):947-958. doi: 10.1109/TUFFC.2017.2685525. Epub 2017 Mar 21.
Minimum variance beamformer (MVB) increases the resolution and contrast of medical ultrasound imaging compared with nonadaptive beamformers. These advantages come at the expense of high computational complexity that prevents this adaptive beamformer to be applied in a real-time imaging system. A new beamspace (BS) based on discrete cosine transform is proposed in which the medical ultrasound signals can be represented with less dimensions compared with the standard BS. This is because of symmetric beampattern of the beams in the proposed BS compared with the asymmetric ones in the standard BS. This lets us decrease the dimensions of data to two, so a high complex algorithm, such as the MVB, can be applied faster in this BS. The results indicated that by keeping only two beams, the MVB in the proposed BS provides very similar resolution and also better contrast compared with the standard MVB (SMVB) with only 0.44% of needed flops. Also, this beamformer is more robust against sound speed estimation errors than the SMVB.
最小方差波束形成器 (MVB) 与非自适应波束形成器相比，提高了医学超声成像的分辨率和对比度。这些优势是以高计算复杂度为代价的，这使得这种自适应波束形成器无法应用于实时成像系统。提出了一种新的基于离散余弦变换的波束空间 (BS)，与标准 BS 相比，该 BS 可以用更少的维度来表示医学超声信号。这是因为与标准 BS 中的非对称波束图相比，该 BS 中的波束具有对称的波束图。这使得我们可以将数据的维度降低到两个，因此可以更快地在这个 BS 中应用高复杂度算法，如 MVB。结果表明，通过仅保留两个波束，与仅需 0.44%的 FLOP 的标准 MVB (SMVB) 相比，在新的 BS 中应用 MVB 可以提供非常相似的分辨率，并且对比度也更好。此外，与 SMVB 相比，这种波束形成器对声速估计误差更具鲁棒性。
