MRI of the Human Retina

糖尿病视网膜病变(DR)是糖尿病的并发症，也是致盲的主要原因 在工作年龄的成年人中，是一种视网膜疾病，其长期病程通常提前数年开始 去做诊断。目前，DR是根据临床检查结果来诊断的；当这些 对于大多数患者来说，视网膜已经发生了明显的、不可逆的损害。 供氧不足和低氧与高能量的光感受器相关 与疾病的早期阶段有牵连。这样的氧气输送-利用不匹配 最终导致晚期新生血管形成和视力丧失。我们假设 视网膜中氧气输送和利用的不匹配导致血液和组织的异常 视力丧失前糖尿病视网膜病变早期的氧合作用。目前，没有现有的非 可用于检测这些早期变化的侵入性成像技术，当干预可以 发挥最大的作用。成像技术可以检测血流的早期变化和 氧合可以加速DR的早期检测，提供集中的人群筛查 风险，并实现纵向治疗监测。及早发现有可能预防 失明和改善治疗结果，包括生活质量。 大多数现有的视网膜成像技术缺乏深度分辨信息(光学除外 用于解剖成像的相干层析)，并且依赖于光学透明度 经常受到媒体混浊的阻碍(例如，白内障和玻璃体出血)。相比之下， MRI可以提供椎板特定深度的解剖、生理和功能数据 决议。然而，它在薄视网膜上的应用一直是具有挑战性的。我们的团队 率先在动物身上进行了多参数、层特异性视网膜磁共振成像，并展示了一些 优势得天独厚。这项建议旨在迈出第一步，将这一创新 研究人类视网膜的方法。我们的中心假设是：i)高分辨率磁共振成像可以 提供具有层状结构的人体视网膜的解剖、生理和功能图像 解决方案，以及ii)DR患者的功能和生理变化将在 可以检测到结构异常。

Diabetic retinopathy (DR), a complication of diabetes and the leading cause of blindness in working-age adults, is a retinal disease whose prolonged course typically begins years prior to diagnosis. DR is presently diagnosed by clinical findings on examination; by the time these are visible, significant irreversible damage to the retina has already occurred for most patients. Insufficient oxygen delivery and hypoxia associated with the energy-demanding photoreceptors has been implicated in the early stage of the disease. Such oxygen delivery-utilization mismatch ultimately precipitates late stage neovascularization and vision loss. We hypothesize that the mismatch in oxygen delivery-utilization in the retina results in abnormal blood flow and tissue oxygenation in the early stage of DR before vision loss. Currently, there are no existing non- invasive imaging technologies available to detect these early changes, when intervention could be most effective. Imaging technologies that can detect early changes in blood flow and oxygenation could accelerate early detection of DR, offer focused screening of population at risk, and enable longitudinal treatment monitoring. Early detection has the potential to prevent blindness and improve treatment outcomes, including quality of life. Most existing retinal imaging techniques lack depth-resolved information (except optical coherence tomography for anatomical imaging) and rely on optical transparency which is frequently hampered by media opacity (e.g., cataracts and vitreous hemorrhages). In contrast, MRI can provide anatomical, physiological, and functional data with lamina-specific depth resolution. Its application to the thin retina, however, has been challenging. Our group pioneered multi-parametric, layer-specific retinal MRI in animals and has demonstrated some unique advantages. This proposal aims to take the first step to translate this innovative approach to study the human retina. Our central hypothesis is that: i) high-resolution MRI can provide anatomical, physiological, and functional images of the human retina with laminar resolution, and ii) functional and physiological changes in DR patients will occur before structural abnormalities can be detected.