MRI of the Human Retina

糖尿病视网膜病变（DR）是糖尿病的一种并发症，也是导致失明的主要原因 在工作年龄的成年人中，是一种视网膜疾病，其长期病程通常在几年前开始 诊断。DR目前是通过检查的临床结果诊断的;到这些时候， 虽然视网膜损伤是可见的，但对于大多数患者来说，已经发生了对视网膜的显著的不可逆损伤。 与需要能量的光感受器相关的氧气输送不足和缺氧 与疾病的早期阶段有关。这种氧气输送-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 视网膜中氧输送-利用的不匹配导致异常的血流和组织 在视力丧失之前的DR早期阶段进行氧合。目前，没有现有的非- 侵入性成像技术可以检测这些早期变化，当干预可以 最有效。成像技术可以检测血流的早期变化， 氧合可以加速DR的早期检测， 风险，并实现纵向治疗监测。早期发现有可能预防 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（除了光学成像技术）。 用于解剖成像的相干断层扫描）并且依赖于光学透明度， 经常受到介质不透明性的阻碍（例如，白内障和玻璃体破裂）。与此相反的是， 磁共振成像可以提供解剖，生理和功能数据与椎板的具体深度 分辨率然而，将其应用于薄视网膜一直具有挑战性。我们集团 率先在动物中进行多参数、层特异性视网膜MRI，并证明了一些 独特的优势该提案旨在迈出第一步，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MRI可以 提供具有层状结构的人类视网膜的解剖学、生理学和功能图像 和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.