Urs Raksha, Ketterling Jeffrey A, Yu Alfred C H, Lloyd Harriet O, Yiu Billy Y S, Silverman Ronald H
Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.
F.L. Lizzi Center for Bioengineering, Riverside Research, New York, NY, USA.
Transl Vis Sci Technol. 2018 Sep 4;7(5):5. doi: 10.1167/tvst.7.5.5. eCollection 2018.
The choroid is a vascular network providing the bulk of the oxygen and nutrient supply to the retina and may play a pivotal role in retinal disease pathogenesis. While optical coherence tomography angiography provides an en face depiction of the choroidal vasculature, it does not reveal flow dynamics. In this report, we describe the use of plane-wave ultrasound to image and characterize choroidal blood flow.
We scanned both eyes of 12 healthy subjects in a horizontal plane superior to the optic nerve head using an 18-MHz linear array. Plane-wave data were acquired over 10 transmission angles that were coherently compounded to produce 1000 images/sec for 3 seconds. These data were processed to produce a time series of power Doppler images and spectrograms depicting choroidal flow velocity. Analysis of variance was used to characterize peak systolic, and end diastolic velocities and resistive index, and their variability between scans, eyes, and subjects.
Power Doppler images showed distinct arterioles within a more diffuse background. Choroidal flow was moderately pulsatile, with peak systolic velocity averaging approximately 10 mm/sec and resistive index of 0.55. There was no significant difference between left and right eyes, but significant variation among subjects.
Plane-wave ultrasound visualized individual arterioles and allowed measurement of flow over the cardiac cycle. Characterization of choroidal flow dynamics offers a novel means for assessment of the choroid's role in ocular disease.
Characterization of choroidal flow dynamics offers a novel means for assessment of the choroid's role in ocular disease.
脉络膜是一个血管网络，为视网膜提供大部分氧气和营养供应，可能在视网膜疾病发病机制中起关键作用。虽然光学相干断层扫描血管造影可提供脉络膜血管系统的正面图像，但它无法揭示血流动力学。在本报告中，我们描述了使用平面波超声对脉络膜血流进行成像和特征分析。
我们使用18MHz线性阵列在视神经乳头上方的水平面上对12名健康受试者的双眼进行扫描。在10个发射角度上采集平面波数据，并进行相干合成，以每秒1000幅图像的速度采集3秒。对这些数据进行处理，以生成描绘脉络膜血流速度的功率多普勒图像和频谱图的时间序列。使用方差分析来表征收缩期峰值、舒张末期速度和阻力指数，以及它们在扫描、眼睛和受试者之间的变异性。
功率多普勒图像显示在更弥散的背景中有明显的小动脉。脉络膜血流呈中度搏动性，收缩期峰值速度平均约为10mm/秒，阻力指数为0.55。左右眼之间无显著差异，但受试者之间存在显著差异。
平面波超声可显示单个小动脉，并能测量心动周期内的血流。脉络膜血流动力学特征分析为评估脉络膜在眼部疾病中的作用提供了一种新方法。
脉络膜血流动力学特征分析为评估脉络膜在眼部疾病中的作用提供了一种新方法。
