OXYGENATION AND PERFUSION IMAGING OF THE CAT RETINA

猫视网膜的氧合和灌注成像

• 批准号: 7562635
• 负责人: Timothy Q. Duong
• 金额: $ 4.74万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7562635
• 关键词: Air; Blindness; Blood flow; Brain Mapping; Clinical; Computer Retrieval of Information on Scientific Projects Database; Cranial Sinuses; Deformity; Diabetic Retinopathy; Diagnosis; Eye; Felis catus; Functional Magnetic Resonance Imaging; Funding; Glaucoma; Goals; Grant; Image; Institution; Invasive; Macular degeneration; Magnetic Resonance Imaging; Maps; Measures; Methodology; Methods; Modeling; Nasal cavity; Nutrient; Oxygen; Perfusion; Perfusion Weighted MRI; Research; Research Personnel; Resolution; Resources; Retina; Retinal; Retinal Diseases; Signal Transduction; Source; Stimulus; Symptoms; Techniques; Tissues; United States National Institutes of Health; Visual impairment; base; blood oxygen level dependent; cell injury; visual stimulus

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The retina is metabolically very active. With limited energy reserve, the retina depends solely on a continuous and adequate supply of oxygen and nutrients to maintain its functional and structural integrity. If blood flow is compromised, irreversible retinal cell damage could occur within minutes, which could result in visual impairment or vision loss. Oxygenation and perfusion deficits have been implicated in numerous retinal diseases, including diabetic retinopathy, glaucoma and macular degeneration. A non-invasive method to measure retinal oxygenation and perfusion at tissue level would be valuable since changes in these parameters generally precede anatomical abnormalities and/or clinical symptoms. The long-term goal of this project is to establish a non-invasive method, using magnetic resonance imaging (MRI), to assist clinicians in the diagnosis and treatment of retinal diseases. The immediate objective of this proposal is to develop a non-invasive MRI methodology to dynamically map changes in retinal oxygenation and perfusion following visual stimuli. While functional MRI (fMRI) and perfusion imaging using the conventional gradient-echo, blood-oxygenation-level-dependent (BOLD) technique is routine for non-invasive mapping of brain functions, its application to the eye is technically more difficult because of the retina's proximity to the air-filled cranial sinuses and nasal cavity. These large air-tissue interfaces could cause drastic signal loss and image distortion. In this application, we will develop and validate a BOLD fMRI technique to measure stimulus-evoked oxygenation changes, and a perfusion-based fMRI technique to measure stimulus-evoked perfusion changes at very high spatial resolution. These techniques will then be applied to evaluate changes in retinal oxygenation and perfusion following to visual stimuli. We will to carry out these studies on a cat model using a 4.7 Tesla magnet.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 视网膜代谢非常活跃。凭借有限的能源储备，视网膜仅取决于氧气和养分的连续和足够的供应，以维持其功能和结构完整性。如果血流受到损害，可能会在几分钟内发生不可逆的视网膜细胞损伤，这可能导致视觉障碍或视力丧失。氧合和灌注不足已与许多视网膜疾病有关，包括糖尿病性视网膜病，青光眼和黄斑变性。在组织水平上测量视网膜氧合和灌注的一种非侵入性方法将是有价值的，因为这些参数的变化通常先于解剖异常和/或临床症状。该项目的长期目标是使用磁共振成像（MRI）建立一种非侵入性方法，以协助临床医生诊断和治疗视网膜疾病。该建议的直接目的是开发一种非侵入性MRI方法，以动态绘制视觉刺激后视网膜氧合和灌注的变化。 尽管使用常规梯度回声进行功能性MRI（fMRI）和灌注成像，但血氧化水平依赖性（BOLD）技术是常规的，用于对脑功能的非侵入性映射，但在技术上，它的应用在技术上更加困难，因为视网膜与空气填充的颅鼻鼻塞和鼻腔腔和鼻腔腔的临近。这些大型空气组织接口可能会导致急剧的信号丢失和图像失真。在此应用中，我们将开发并验证一种大胆的fMRI技术，以测量刺激引起的氧合变化，以及一种基于灌注的FMRI技术，以测量在非常高的空间分辨率下刺激刺激引起的灌注变化。然后，这些技术将用于评估视觉刺激之后的视网膜氧合和灌注的变化。我们将使用4.7 Tesla磁铁对CAT模型进行这些研究。