MRI AND QUANTITATION OF OCULAR CIRCULATION

MRI 和眼循环定量

• 批准号: 3266321
• 负责人: HONG-MING CHENG
• 金额: $ 13.42万
• 依托单位: MASSACHUSETTS EYE AND EAR INFIRMARY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-03-01 至 1996-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3266321
• 关键词: acetazolamide; carbonic anhydrase inhibitors; eye circulation; eye pharmacology; fluid flow; glaucoma; imaging /visualization /scanning; intraocular aqueous flow; laboratory rabbit; magnetic resonance imaging; ocular hypotensive; pilocarpine

The principal objective of this proposal is to apply magnetic resonance (MR) imaging to the quantitation of fluid (water) movement in the anterior chamber of the living rabbit eye. We use a novel approach using topically applied GdDTPA and H217O, T1 and T2 contrast agents, respectively, as the tracers. Spin-echo MR imaging will be performed using a 1.5 Tesla imager in conjunction with small (2-5 inch diameter) radio-frequency surface coils. Fast imaging techniques also will be adopted (when available) which permit the collection of more data points and reduction of motion artifacts. MR imaging technique enables us, for the first time, to visualize and quantify the flow of water including aqueous outflow, iris circulation, and water diffusion in the eye. There are no comparable clinical techniques now in existence. The specific aims are: (1) to refine methods for the study of ocular fluid flow using topical GdDTPA and H217O; (2) to quantify the fluid flow in the anterior chamber; and (3) to test the effects of three anti- glaucoma agents, pilocarpine (a miotic), acetazolamide (a carbonic anhydrase inhibitor), and timolol (a non-specific beta-blocker) on the kinetics of the fluid flow. We expect to accomplish the following: (1) documentation of aqueous/water flow dynamics; (2) evaluation of the fluid flow altered by anti-glaucoma agents; and (3) development of novel MRI diagnostic techniques for the evaluation of the fluid flow. The results of these studies will further our understanding of the aqueous/water flow dynamics. The diagnostic techniques will permit us to evaluate changes in the fluid flow in primary open-angle glaucoma, nanophthalmos, narrow-angle glaucoma, neovascular glaucoma, and their malignant forms, and aid eventually in the management of these diseases.

这项提议的主要目标是应用磁共振 (MR)成像用于定量流体(水)的运动 活体兔眼的前房。我们使用一种新的方法，使用 局部应用GdDTPA和H217O、T1和T2造影剂， 分别作为示踪剂。将进行自旋回波磁共振成像 将1.5特斯拉成像器与小(2-5英寸直径)配合使用 射频表面线圈。快速成像技术也将是 采用(如果可用)，允许收集更多数据点 和减少运动伪影。磁共振成像技术使我们能够 第一次，可视化和量化水的流动，包括 房水流出，虹膜循环，眼内水分扩散。那里 目前还没有类似的临床技术存在。 具体目标是：(1)完善眼科研究方法 使用局部GdDTPA和H_217O进行流体流动；(2)对流体流动进行量化 在前房内；(3)测试三种抗凝剂的效果。 青光眼药物，匹罗卡品(一种近视)，乙酰唑胺(一种碳酸盐) 脱水酶抑制剂)和噻吗洛尔(一种非特异性β-受体阻滞剂)。 流体流动的动力学。 我们希望做到以下几点： (1)水/水流动动力学文件； (2)评估抗青光眼药物改变的液体流量； (3)新的MRI诊断技术的发展 流体流动。 这些研究的结果将进一步加深我们对 水/水流动动力学。诊断技术将允许我们 为了评估原发性开角型青光眼患者体液流动的变化， 纳米眼球、窄角型青光眼、新生血管性青光眼及其 恶性形式，并最终帮助这些疾病的管理。