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Phys Med Biol. 2020 Sep 4;65(17):175002. doi: 10.1088/1361-6560/ab9372.
High-frame-rate volume imaging (HFR-VI) aims to provide high-quality images with high-temporal information. Despite its potential, HFR-VI translation into clinical applications has been challenging due to the high cost of the equipment required to drive matrix probes with a large number of elements. The goal of this study is to introduce and test sparse-random-aperture compounding (SRAC), a technique that allows use of matrix probes with an ultrasound system that has fewer channels while maintaining high frame rates. Four scanning methods were implemented with a 256-channel system using a 4-to-1 multiplexer and a 3 MHz matrix probe with 1024 elements. These methods used three types of waves, either single-diverging waves (SDW), multiplane-diverging waves (MDW) or wide beams (WB); and were driven using one to four SRAC. All methods were also implemented in a 1024-channel multisystem. The main-lobe-to-side-lobe ratio (MLSLR) and the contrast ratio (CR) were studied using a string phantom and a CIRS phantom, respectively. The results showed an increase in the MLSLR and CR as a function of the number of SRAC. The multisystem provided the best results for the MLSLR. However, four SRAC outperformed the multisystem with respect to CR. The method using SDW provided the highest frame rates (i.e. 1875 and 7500 Hz for four and one SRAC, respectively), however it provided the lowest image quality. The two methods using MDWs showed a good compromise between image quality and frame rate (i.e. 187 to 750 Hz for four and one SRAC). WB provided the best image quality at the expense of frame rate (i.e. 18 to 75 Hz for four and one SRAC). Our results suggest that SRAC in combination with the tested scanning methods can provide a low-channel count alternative for HFR-VI systems and allows a tunable tradeoff between image quality and frame rate guided by the desired application.
高帧率容积成像（HFR-VI）旨在提供具有高时间信息的高质量图像。尽管有潜力，但由于驱动具有大量元件的矩阵探头所需的设备成本高昂，HFR-VI 转化为临床应用一直具有挑战性。本研究的目的是介绍和测试稀疏随机孔径复合（SRAC）技术，该技术允许在通道较少的超声系统中使用矩阵探头，同时保持高帧率。使用具有 1024 个元件的 4 到 1 复用器和 3 MHz 矩阵探头，在 256 通道系统上实现了四种扫描方法。这些方法使用了三种类型的波，即单扩散波（SDW）、多平面扩散波（MDW）或宽波束（WB）；并使用一个到四个 SRAC 进行驱动。所有方法也在 1024 通道多系统中实现。使用字符串幻影和 CIRS 幻影分别研究了主瓣到旁瓣比（MLSLR）和对比度比（CR）。结果表明，随着 SRAC 数量的增加，MLSLR 和 CR 均增加。多系统为 MLSLR 提供了最佳结果。然而，在 CR 方面，四个 SRAC 优于多系统。使用 SDW 的方法提供了最高的帧率（即四个和一个 SRAC 的帧率分别为 1875 和 7500 Hz），然而，它提供了最低的图像质量。使用 MDW 的两种方法在图像质量和帧率之间显示出良好的折衷（即四个和一个 SRAC 的帧率分别为 187 至 750 Hz）。WB 以牺牲帧率为代价提供了最佳的图像质量（即四个和一个 SRAC 的帧率分别为 18 至 75 Hz）。我们的结果表明，SRAC 与测试的扫描方法相结合，可以为 HFR-VI 系统提供一种低通道计数的替代方案，并允许根据所需的应用在图像质量和帧率之间进行可调的权衡。
