HIGH RESOLUTION BLOOD FLOW MAPPING IN OCULAR TISSUES

眼组织高分辨率血流图

• 批准号: 6652510
• 负责人: Katherine W Ferrara
• 金额: $ 20.74万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2004-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6652510
• 关键词: bioimaging /biomedical imaging; cats; clinical research; diagnosis design /evaluation; drug screening /evaluation; eye circulation; eye disorder chemotherapy; eye disorder diagnosis; fluorescent dye /probe; glaucoma; human subject; human therapy evaluation; intravital microscopy; laboratory rabbit; laboratory rat; noninvasive diagnosis; ocular hypotensive; optic nerve; ultrasound blood flow measurement; uvea ciliary body

We have developed a new high-frequency ultrasound scanning system that provides the opportunity to obtain a two-dimensional map of blood flow in the anterior segment of the eye in one second, with spatial resolution on the order of 40 microns and velocity resolution on the order of 0.2 mm/s. This represents approximately an order of magnitude improvement in resolution over existing techniques, and provides the first non-invasive opportunity to evaluate blood flow in arterioles and venules in opaque tissues. In addition, a new strategy to estimate capillary volume and flow rate has been developed by combining a theoretical model and a system to interrogate individual contrast microbubbles. This new suite of tools can be applied to improve the understanding of the mechanisms of ophthalmic diseases including glaucoma and age-related macular degeneration as well as the mechanisms and effectiveness of treatment options. Here, we specifically address glaucoma. The clinical significance of an improvement in the management of ophthalmic diseases is enormous since 3 million people in the US alone suffer from glaucoma, 100,000 per year suffer some form of ocular trauma, and over 6 million people in the US suffer from degenerative retinal diseases. Most experts agree that glaucoma is a series of conditions characterized by a particular form of optic nerve damage that is often associated with elevated intra-ocular pressure, although the mechanisms responsible for damage and successful therapy are not understood. Many drug therapies for glaucoma are assumed to decrease intra-ocular pressure through the constriction of arterioles in the ciliary body, however, it has been impossible to measure these changes in ciliary body blood flow, or to measure optic nerve head perfusion. Our new technique to estimate arteriolar diameter and flow rate will be evaluated in a human study of glaucoma therapies. Contrast-assisted methods for the estimation of capillary volume and flow rate will be developed for the high resolution requirements of ophthalmology. This requires the further development of our experimental system, the evaluation of new contrast agents with higher resonant frequencies, and the validation of our new strategies for the estimation of capillary density. These new techniques will be used to evaluate perfusion in the ciliary body and in the optic nerve head in an animal model study of drug therapies, and compared with the output of a scanning laser Doppler flowmeter. In conjunction with this study, mechanical damage to the vessel wall will be directly assessed through the use of fluorescent markers.

我们开发了一种新型高频超声扫描系统，可以在一秒钟内获得眼前节血流的二维图，空间分辨率达到 40 微米量级，速度分辨率达到 40 微米量级。 0.2毫米/秒的数量级。 这代表了现有技术的分辨率大约提高了一个数量级，并提供了第一个非侵入性机会来评估不透明组织中的小动脉和小静脉的血流。 此外，通过结合理论模型和询问单个对比微泡的系统，开发了一种估计毛细管体积和流速的新策略。 这套新工具可用于增进对青光眼和年龄相关性黄斑变性等眼科疾病机制以及治疗方案的机制和有效性的理解。 在这里，我们专门针对青光眼。 改善眼科疾病管理的临床意义是巨大的，因为仅在美国就有 300 万人患有青光眼，每年有 10 万人遭受某种形式的眼外伤，并且超过 600 万人患有退行性视网膜疾病。 大多数专家一致认为，青光眼是一系列以特定形式的视神经损伤为特征的疾病，这种损伤通常与眼内压升高有关，尽管造成损伤的机制和成功的治疗尚不清楚。许多青光眼药物疗法被认为是通过收缩睫状体中的小动脉来降低眼内压，然而，不可能测量睫状体血流量的这些变化，或测量视神经乳头灌注。 我们估计小动脉直径和流速的新技术将在青光眼治疗的人体研究中进行评估。将开发用于估计毛细血管体积和流速的对比辅助方法，以满足眼科的高分辨率要求。 这需要进一步开发我们的实验系统，评估具有更高共振频率的新造影剂，并验证我们估计毛细血管密度的新策略。 这些新技术将用于在药物治疗的动物模型研究中评估睫状体和视神经头的灌注，并与扫描激光多普勒流量计的输出进行比较。 结合这项研究，将通过使用荧光标记直接评估血管壁的机械损伤。

项目成果

High-frequency dynamics of ultrasound contrast agents.

超声造影剂的高频动力学。

• 发表时间: 2005-11
• 作者: Sun, Yang;Kruse, Dustin E;Dayton, Paul A;Ferrara, Katherine W
• 通讯作者: Ferrara, Katherine W