IEEE Trans Ultrason Ferroelectr Freq Control. 2024 Jun;71(6):659-672. doi: 10.1109/TUFFC.2024.3396269. Epub 2024 Jun 10.
The widely used Vermon 1024-element matrix array for 3-D ultrasound imaging has three blank rows in the elevational direction, which breaks the elevation periodicity, thus degrading volumetric image quality. To bypass the blank rows in elevation while maintaining the steering capability in azimuth, we proposed a row-transmission (RT) scheme to improve 3-D spatial resolution. Specifically, we divided the full array into four apertures, each with multiple rows along the elevation. Each multirow aperture (MRA) was further divided into subapertures to transmit diverging waves (DWs) sequentially. Coherent DW compounding (CDWC) was realized in azimuth, while the elevation was multielement synthetic aperture (M-SA) imaging by regarding each row as an array of dashed line elements. An in-house spatiotemporal coding strategy, cascaded synthetic aperture (CaSA), was incorporated into the RT scheme as RT-CaSA to increase the signal-to-noise ratio (SNR). We compared the proposed RT with conventional bank-by-bank transmission-reception (Bank) and sparse-random-aperture compounding (SRAC) in a wire phantom and the in vivo human abdominal aorta (AA) to assess the performance of anatomical imaging and aortic wall motion estimation. Phantom results demonstrated superior lateral resolution achieved by our RT scheme (+19.52% and +16.88% versus Bank, +15.32% and +19.72% versus SRAC, in the azimuth-depth and elevation-depth planes, respectively). Our RT-CaSA showed excellent contrast ratios (CRs) (+8.19 and +8.08 dB versus Bank, +6.81 and +5.85 dB versus SRAC, +0.99 and +0.90 dB versus RT) and the highest in vivo aortic wall motion estimation accuracy. The RT scheme was demonstrated to have potential for various matrix array-based 3-D imaging research.
广泛用于 3-D 超声成像的 Vernon 1024 元矩阵阵列在高程方向有三行空白行，破坏了高程周期性，从而降低了体积图像质量。为了在保持方位转向能力的同时绕过高程中的空白行，我们提出了一种行传输 (RT) 方案来提高 3-D 空间分辨率。具体来说，我们将整个阵列分为四个孔径，每个孔径在高程方向有多行。每个多行孔径 (MRA) 进一步分为子孔径，以顺序发射发散波 (DW)。在方位上实现相干 DW 复合 (CDWC)，而在高程上则通过将每一行视为虚线元素的阵列进行多元素合成孔径 (M-SA) 成像。我们将一种内部时空编码策略，级联合成孔径 (CaSA)，纳入 RT 方案中，作为 RT-CaSA，以提高信噪比 (SNR)。我们在金属丝体模和体内人腹主动脉 (AA) 中比较了所提出的 RT 与传统的逐列传输-接收 (Bank) 和稀疏随机孔径复合 (SRAC)，以评估解剖成像和主动脉壁运动估计的性能。体模结果表明，我们的 RT 方案在侧向分辨率方面具有优势（在方位-深度和高程-深度平面上分别比 Bank 提高了+19.52%和+16.88%，比 SRAC 提高了+15.32%和+19.72%）。我们的 RT-CaSA 显示出出色的对比度比（与 Bank 相比分别为+8.19 和+8.08 dB，与 SRAC 相比分别为+6.81 和+5.85 dB，与 RT 相比分别为+0.99 和+0.90 dB）和最高的体内主动脉壁运动估计精度。RT 方案被证明在各种基于矩阵阵列的 3-D 成像研究中具有潜力。
