Retinal Hemodynamic Imaging with Tracking Doppler Flowmetry

使用跟踪多普勒血流计进行视网膜血流动力学成像

• 批准号: 7053644
• 负责人: R DANIEL FERGUSON
• 金额: $ 15.99万
• 依托单位: PHYSICAL SCIENCES, INC
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-30 至 2008-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7053644
• 关键词: blood; clinical research; eye

DESCRIPTION (provided by applicant): Physical Sciences Inc. (PSI) proposes to combine new and existing retinal imaging technologies to yield powerful new dye-free, functional imaging capabilities to ocular blood flow. We have previously demonstrated a new technique called tracking Doppler flowmetry (TDF) for the acquisition of wide-field, high dynamic range Doppler frequency-resolved maps of the retina. In this manner, blood flow information can be displayed and quantified with novel binning, color encoding, and equalization techniques for eyes with diseases such as age-related macular degeneration, or in response to factors affecting neuronal or metabolic activity (light stimulation, exercise, or pharmaceutical agent). The long confocal range gate of TDF is at once beneficial, providing high flow sensitivity and contrast due to inclusion of multiple-scattering events, large scattering receive angle, and low sensitivity to input beam angle within a long interaction range, and detrimental in terms of axial localization of flow. Optical Doppler tomography, conversely, has a narrow coherence range gate that provides high axial flow discrimination but is sensitive only to single-scattering with axial velocity components in a narrow acceptance angle. In the proposed program, we will develop 2 methods for improved axially discrimination with TDF: stereoscopic operation and hybridization with swept sources using the principles of Fourier domain optical coherence tomography. Advanced data processing algorithms will also be implemented. The improved system will be tested in human volunteers to 1) demonstrate quantifiable and reproducible depth-resolved retinal Doppler blood flow mapping; 2) measure blood flow changes in relation to visual stimulus-evoked neuro-vascular coupling mechanisms; and 3) enable detailed pulsatile flow phase portraits across a range of vessel sizes and flow velocity by synchronization to the cardiac cycle. This work will provide a valuable diagnostic tool to clinicians and researchers for the study of retinal function and the mechanisms and treatment of eye disease. Relevance of this research to public health: The retina is 1 of the most highly vascularized tissues in the body and is also most susceptible to damage from deficits in blood flow. Many degenerative and angiogenerative diseases of the eye, such as age-related macular degeneration and diabetic retinopathy, have either hemodynamic consequences or causes, though many of the mechanisms remain unknown or obscure. Development of better diagnostic tools will lead to increased understanding of the contribution of vascular blood flow and capillary perfusion to the inception and progression of retinal diseases, and also to research on visual signal transduction, higher order brain processing and modulation, and the study of advanced therapeutic interactions and pharmaceutical effects.

描述（由申请人提供）：Physical Sciences Inc. (PSI)提出将新的和现有的视网膜成像技术联合收割机组合以产生对眼睛血流的强大的新的无染料的功能性成像能力。我们以前已经证明了一种新的技术，称为跟踪多普勒血流仪（TDF）的收购宽领域，高动态范围多普勒频率分辨地图的视网膜。以这种方式，对于患有诸如年龄相关性黄斑变性之类的疾病的眼睛，或者响应于影响神经元或代谢活动的因素（光刺激、锻炼或药剂），可以利用新颖的分箱、颜色编码和均衡技术来显示和量化血流信息。TDF的长共焦范围选通同时是有益的，由于包括多次散射事件、大散射接收角和对长相互作用范围内的输入光束角的低灵敏度而提供高流动灵敏度和对比度，并且在流动的轴向定位方面是有害的。相反，光学多普勒层析成像具有窄的相干范围门，其提供高的轴向流鉴别，但仅对在窄的接收角中具有轴向速度分量的单次散射敏感。在所提出的计划中，我们将开发2种方法，以提高轴向歧视与TDF：立体操作和杂交与扫频源使用傅立叶域光学相干层析成像的原则。还将采用先进的数据处理算法。改进的系统将在人类志愿者中进行测试，以1）证明可量化和可再现的深度分辨视网膜多普勒血流图; 2）测量与视觉刺激诱发的神经血管耦合机制相关的血流变化; 3）通过与心动周期同步，在一系列血管尺寸和流速范围内实现详细的脉动流相位图。这项工作将为临床医生和研究人员提供一个有价值的诊断工具，用于研究视网膜功能和眼科疾病的机制和治疗。这项研究与公共卫生的相关性：视网膜是体内血管化程度最高的组织之一，也最容易受到血流不足的损害。许多眼部退行性和血管生成性疾病，如年龄相关性黄斑变性和糖尿病视网膜病变，都有血液动力学后果或原因，尽管许多机制仍然未知或模糊。更好的诊断工具的发展将导致增加对血管血流和毛细血管灌注对视网膜疾病的发生和进展的贡献的理解，以及对视觉信号转导、高阶脑处理和调制的研究，以及先进的治疗相互作用和药物作用的研究。