AI 中文总结
本文提出锁相时间拉伸光学相干断层扫描微血管造影系统，通过双啁啾光纤布拉格光栅等技术实现高分辨率、高对比度视网膜微血管成像，性能优于现有系统，可用于相关疾病的诊断监测。
AI 中文摘要
光学相干断层扫描血管造影（Optical Coherence Tomography Angiography）已通过提供非侵入性、高分辨率的可视化，革新了视网膜血管成像领域。然而，在视场、分辨率与三维微血管对比度之间实现最优平衡，尤其是在较深视网膜层中，仍然是一项挑战。为解决这些局限，本文开发了一种锁相时间拉伸光学相干断层扫描微血管造影系统，该系统具备5 MHz的A线速率与亚纳米级相位灵敏度。该系统采用双啁啾光纤布拉格光栅（dual chirped fiber Bragg grating）架构，使扫频光源激光器实现了约10 mm的延长相干长度与102 nm的带宽。时间拉伸模数转换器（time-stretch analog-to-digital converter）克服了传统多MHz光学相干断层扫描系统的局限，确保在空气中实现2 mm的成像深度与高空间分辨率。所提出的系统能够对关键视网膜结构进行高对比度、深度编码的映射，包括浅层和深层毛细血管丛以及脉络膜毛细血管层。与最先进的系统相比，该方法展现出更高的分辨率、更优的对比度与更快的成像速度，提升了其在诊断和监测视网膜及全身性疾病（如年龄相关性黄斑变性、糖尿病视网膜病变和阿尔茨海默病）方面的潜力。
英文摘要
Optical coherence tomography angiography has transformed retinal vascular imaging by providing non-invasive, high-resolution visualization. However, achieving an optimal balance between field of view, resolution, and three-dimensional microvasculature contrast, particularly in deeper retinal layers, remains challenging. A phase-locked time-stretch optical coherence tomography microangiography system is developed to address these limitations with a 5-MHz A-line rate and sub-nm phase sensitivity. Utilizing a dual chirped fiber Bragg grating architecture, the swept-source laser achieves an extended coherence length of approximately 10 mm and a 102-nm bandwidth. A time-stretch analog-to-digital converter overcomes the limitations of conventional multi-MHz optical coherence tomography systems, ensuring a 2-mm imaging depth in the air with high spatial resolution. The proposed system enables high-contrast, depth-encoded mapping of key retinal structures, including the superficial and deep capillary plexuses and the choriocapillaris. Compared to a state-of-the-art system, the proposed approach demonstrates enhanced resolution, improved contrast, and faster imaging speeds, enhancing its potential for diagnosing and monitoring retinal and systemic diseases like age-related macular degeneration, diabetic retinopathy, and Alzheimer's disease.
Comments15 pages, 12 figures, 2 tables. Published in IEEE Transactions on Medical Imaging
Journal refIEEE Transactions on Medical Imaging, vol. 44, no. 7, pp. 2906-2920, July 2025
