Department of Biomedical Engineering, Dongguk University, Seoul 04620, Republic of Korea.
Sensors (Basel). 2024 Apr 24;24(9):2700. doi: 10.3390/s24092700.
In general, it is difficult to visualize internal ocular structure and detect a lesion such as a cataract or glaucoma using the current ultrasound brightness-mode (B-mode) imaging. This is because the internal structure of the eye is rich in moisture, resulting in a lack of contrast between tissues in the B-mode image, and the penetration depth is low due to the attenuation of the ultrasound wave. In this study, the entire internal ocular structure of a bovine eye was visualized in an ex vivo environment using the compound acoustic radiation force impulse (CARFI) imaging scheme based on the phase-inverted ultrasound transducer (PIUT). In the proposed method, the aperture of the PIUT is divided into four sections, and the PIUT is driven by the out-of-phase input signal capable of generating split-focusing at the same time. Subsequently, the compound imaging technique was employed to increase signal-to-noise ratio (SNR) and to reduce displacement error. The experimental results demonstrated that the proposed technique could provide an acoustic radiation force impulse (ARFI) image of the bovine eye with a broader depth-of-field (DOF) and about 80% increased SNR compared to the conventional ARFI image obtained using the in-phase input signal. Therefore, the proposed technique can be one of the useful techniques capable of providing the image of the entire ocular structure to diagnose various eye diseases.
一般来说，使用当前的超声亮度模式（B 模式）成像技术，很难对眼内结构进行可视化，也很难检测白内障或青光眼等病变。这是因为眼睛的内部结构富含水分，导致 B 模式图像中组织之间缺乏对比度，而且由于超声波的衰减，穿透深度较低。在这项研究中，使用基于相控反转超声换能器（PIUT）的复合声辐射力脉冲（CARFI）成像方案，在离体环境下对牛眼的整个眼内结构进行了可视化。在提出的方法中，PIUT 的孔径分为四个部分，PIUT 由能够同时产生分焦的相差输入信号驱动。随后，采用复合成像技术来提高信噪比（SNR）并降低位移误差。实验结果表明，与使用同相输入信号获得的常规 ARFI 图像相比，所提出的技术可以提供具有更宽景深（DOF）和大约 80%的 SNR 增强的牛眼 ARFI 图像。因此，该技术可以成为提供整个眼部结构图像以诊断各种眼部疾病的有用技术之一。
