Jia Yurou, Zhang Suying, Zhang Xuan, Long Houyou, Xu Caibin, Bai Yechao, Cheng Ying, Wu Dajian, Deng Mingxi, Qiu Cheng-Wei, Liu Xiaojun
Department of Physics, MOE Key Laboratory of Modern Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore.
Nat Commun. 2024 Apr 5;15(1):2934. doi: 10.1038/s41467-024-47303-7.
Ultrasonic imaging is crucial in the fields of biomedical engineering for its deep penetration capabilities and non-ionizing nature. However, traditional techniques heavily rely on impedance differences within objects, resulting in poor contrast when imaging acoustically transparent targets. Here, we propose a compact spatial differentiator for underwater isotropic edge-enhanced imaging, which enhances the imaging contrast without the need for contrast agents or external physical fields. This design incorporates an amplitude meta-grating for linear transmission along the radial direction, combined with a phase meta-grating that utilizes focus and spiral phases with a first-order topological charge. Through theoretical analysis, numerical simulations, and experimental validation, we substantiate the effectiveness of our technique in distinguishing amplitude objects with isotropic edge enhancements. Importantly, this method also enables the accurate detection of both phase objects and artificial biological models. This breakthrough creates new opportunities for applications in medical diagnosis and nondestructive testing.
超声成像因其深度穿透能力和非电离特性在生物医学工程领域至关重要。然而，传统技术严重依赖物体内部的阻抗差异，在对声学透明目标成像时对比度较差。在此，我们提出一种用于水下各向同性边缘增强成像的紧凑型空间微分器，它无需造影剂或外部物理场即可增强成像对比度。该设计包含一个用于沿径向线性传输的振幅超光栅，以及一个利用具有一阶拓扑电荷的聚焦和螺旋相位的相位超光栅。通过理论分析、数值模拟和实验验证，我们证实了我们的技术在区分具有各向同性边缘增强的振幅物体方面的有效性。重要的是，该方法还能够准确检测相位物体和人工生物模型。这一突破为医学诊断和无损检测应用创造了新机会。
