Wang Dongyi, Haytham Ayman, Mayo Lakyn, Tao Yang, Saeedi Osamah
Bio-Imaging and Machine Vision Lab, Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
Aureus University School of Medicine, Wayaca 31C, Oranjestad, Aruba.
Biomed Opt Express. 2019 Jun 27;10(7):3681-3697. doi: 10.1364/BOE.10.003681. eCollection 2019 Jul 1.
Retinal blood flow is an emerging biomarker in ocular and systemic disease. Erythrocyte mediated angiography (EMA) is a novel technique that provides an easily interpretable blood flow velocity quantification by directly tracing individual moving erythrocyte ghosts over time in vivo, imaged using a scanning laser ophthalmoscope (Heidelberg Retina Angiograph platform). This tracking procedure, however, requires time-consuming manual analysis to determine blood flow. To overcome this current bottleneck, we developed an objective and automated velocimetry approach, EMA - Automated Velocimetry (EMA-AV), which is based on a modified sequential Monte Carlo method. The intra-class correlation coefficient (ICC) between trained human graders and EMA-AV is 0.98 for mean vessel velocity estimation and 0.92 for frame by frame erythrocyte velocity estimation. This study proves EMA-AV is a reliable tool for quantification of retinal microvascular velocity and flow and establishes EMA-AV as a reliable and interpretable tool for quantifying retinal microvascular velocity.
视网膜血流是眼科和全身性疾病中一种新兴的生物标志物。红细胞介导血管造影术（EMA）是一种新技术，通过在体内随时间直接追踪单个移动的红细胞残影来提供易于解释的血流速度定量分析，使用扫描激光检眼镜（海德堡视网膜血管造影平台）进行成像。然而，这种追踪过程需要耗时的人工分析来确定血流情况。为了克服当前这一瓶颈，我们开发了一种客观且自动化的测速方法，即EMA - 自动测速法（EMA - AV），它基于一种改进的序贯蒙特卡罗方法。对于平均血管速度估计，训练有素的人工分级员与EMA - AV之间的组内相关系数（ICC）为0.98，对于逐帧红细胞速度估计，ICC为0.92。本研究证明EMA - AV是一种用于定量视网膜微血管速度和血流的可靠工具，并将EMA - AV确立为一种用于量化视网膜微血管速度的可靠且可解释的工具。
