Opt Express. 2024 Sep 9;32(19):32799-32812. doi: 10.1364/OE.528684.
Endoscopic optical coherence tomography (OCT) is widely used in the detection of morphological alterations in luminal organs, which provides high-resolution, three-dimensional (3D) images of internal tissues. In most cases, lesions are revealed early by microvascular pathological changes in cavity tissues. There is a significant demand for the performance of endoscopic OCT angiography (OCTA) to visualize the superficial capillaries. Proximal catheters have attracted widespread attention due to the advantages of small size and low cost. However, in comparison with the OCT system using distal catheters, low rotation speed and poor stability of the proximal scanning OCT prolonged its absence of endoscopic OCTA in common commercial and lab systems. In this paper, endoscopic OCTA was realized in the proximal scanning endoscopic OCT system by calculating decorrelation between adjacent B-scan images in the continuous rotation and retraction scheme. A precision registration algorithm was proposed to guarantee the quality of the OCTA image. The feasibility of the endoscopic OCTA was validated using a microfluidic phantom. In vivo studies were performed in the rat rectum, visualizing the intricate microvascular architecture, specifically within the submucosal capillaries. To the best of our knowledge, the first implementation of endoscopic OCTA was achieved under a continuous spiral B-scan rotation scheme in a proximally controlled OCT system, facilitating visualization of blood flow within narrow lumen tissues.
内窥式光学相干断层扫描（OCT）广泛应用于腔道器官内形态改变的检测，它可以提供高分辨率的三维（3D）内部组织图像。在大多数情况下，腔道组织的微血管病理变化会早期揭示病变。内窥式 OCT 血管造影（OCTA）对浅层毛细血管成像的性能有很高的需求。近端导管由于尺寸小、成本低而受到广泛关注。然而，与使用远端导管的 OCT 系统相比，近端扫描 OCT 的旋转速度低且稳定性差，这使得其在常见的商用和实验室系统中缺乏内窥式 OCTA。本文提出了一种在连续旋转和缩回方案中计算相邻 B 扫描图像之间的去相关来实现近端扫描内窥式 OCTA 的方法，并提出了一种精密配准算法来保证 OCTA 图像的质量。通过微流控体模验证了内窥式 OCTA 的可行性。在大鼠直肠进行了体内研究，可视化了复杂的微血管结构，特别是黏膜下毛细血管内的血流。据我们所知，这是首次在近端控制的 OCT 系统中，通过连续螺旋 B 扫描旋转方案实现内窥式 OCTA，便于观察狭窄腔道组织内的血流。
