3D Imaging of the human heart at high frame rate is of major interest for various clinical applications. Electronic complexity and cost has prevented the dissemination of 3D ultrafast imaging into the clinic. Row column addressed (RCA) transducers provide volumetric imaging at ultrafast frame rate by using a low electronic channel count, but current models are ill-suited for transthoracic cardiac imaging due to field-of-view limitations. In this study, we proposed a mechanically curved RCA with an aperture adapted for transthoracic cardiac imaging ( $24\times16$ mm2). The RCA has a toroidal curved surface of 96 elements along columns (curvature radius rC = 4.47 cm) and 64 elements along rows (curvature radius rR = 3 cm). We implemented delay and sum beamforming with an analytical calculation of the propagation of a toroidal wave which was validated using simulations (Field II). The imaging performance was evaluated on a calibrated phantom. Experimental 3D imaging was achieved up to 12 cm deep with a total angular aperture of 30° for both lateral dimensions. The Contrast-to-Noise ratio increased by 12 dB from 2 to 128 virtual sources. Then, 3D Ultrasound Localization Microscopy (ULM) was characterized in a sub-wavelength tube diameter. Finally, 3D ULM was demonstrated on a perfused ex-vivo swine heart to image the coronary microcirculation.

中文翻译：

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用于 3D 超快超声成像的曲面环形排柱寻址传感器


高帧率的人体心脏 3D 成像是各种临床应用的主要关注点。电子复杂性和成本阻碍了 3D 超快成像在临床中的传播。行列寻址 （RCA） 传感器通过使用低电子通道数以超快帧速率提供体积成像，但由于视野限制，目前的型号不适合经胸心脏成像。在这项研究中，我们提出了一种机械弯曲的 RCA，其孔径适用于经胸心脏成像 （ $24\times16$ mm2）。RCA 具有沿列的 96 个元件（曲率半径 rC = 4.47 cm）和沿行的 64 个元件（曲率半径 rR = 3 cm）的环形曲面。我们通过对环形波传播的分析计算实现了延迟和和波束形成，该计算使用仿真进行了验证（场 II）。在校准的模型上评估成像性能。实验性 3D 成像深达 12 cm，两个横向尺寸的总角孔径为 30°。Contrast-to-Noise ratio（对比度与噪声比）从 2 个虚拟源增加到 128 个虚拟源，增加了 12 dB。然后，在亚波长管直径中表征 3D 超声定位显微镜 （ULM）。最后，在灌注的离体猪心脏上演示了 3D ULM，以对冠状动脉微循环进行成像。