Holography-based Photoacoustic Imaging of the Retina

基于全息术的视网膜光声成像

• 批准号: 8584463
• 负责人: Parag Vijay Chitnis
• 金额: $ 19.58万
• 依托单位: RIVERSIDE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2014-08-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8584463
• 关键词: Address; Age related macular degeneration; Anatomy; Animal Model; Animals; Applications Grants; Attenuated; Blood; Blood Circulation; Blood Vessels; Blood flow; Choroid; Clinical; Clinical assessments; Coupling; Crystalline Lens; Data; Detection; Development; Diabetic Retinopathy; Diagnosis; Diagnostic; Disease; Elements; Evaluation; Frequencies; Functional Imaging; Fundus; Generations; Glaucoma; Goals; Hemoglobin; Hemoglobin concentration result; Histology; Holography; Image; Imagery; Imaging Techniques; Interferometry; Lasers; Lateral; Life; Light; Liquid substance; Maps; Measures; Methods; Microscope; Modality; Modification; Mus; Noise; Optic Nerve; Optical Coherence Tomography; Optics; Oryctolagus cuniculus; Oxygen; Performance; Physiologic pulse; Physiology; Property; Resolution; Retina; Retinal; Retinal Diseases; Scanning; Scheme; Signal Transduction; Stress; Structure; Structure of retinal pigment epithelium; Surface; System; Techniques; Thick; Three-Dimensional Image; Time; Tissues; Transducers; Ultrasonography; absorption; base; chromophore; computerized data processing; disease diagnosis; image reconstruction; imaging modality; improved; in vivo; indexing; insight; instrumentation; neovasculature; novel; photoacoustic imaging; pre-clinical; pre-clinical research; pressure; public health relevance; response; sensor; sound; submicron; tomography

The proposed study will assess the feasibility of a novel, all-optical technique for photoacoustic imaging that employs a photorefractive crystal (PRC) and potentially can provide anatomical and functional images of the retina, choroid, and the optic nerve with ultra-fine-resolution. Detailed visualization of retinal substructures and the optic nerve is critical for evaluation of ophthalmic diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD) and glaucoma. However, vascular function and local oxygen delivery also are relevant indicators of the diseased state. Existing diagnostic modalities such as optical coherence tomography (OCT) and ultrasound (US) do not provide this information. Our PRC-based implementation of PAI will address the shortcomings of other imaging modalities while providing sub-micron image resolution and an imaging depth that is 3 to 5 times that of OCT. Furthermore, PAI also can provide functional information such as the level of hemoglobin-oxygen saturation, which can improve clinical assessment of ophthalmic diseases. Our approach does not require fluid coupling or physical contact required by US. Because the proposed holographic implementation of PAI employs a continuous-wave laser and CCD-based full-field interferometry for detecting the photoacoustic (PA) signal, it potentially can acquire 3D-image data in 500 ms (limited only by the frame rate of the camera and the desired bandwidth for PA-signal detection). The CCD- based implementation also facilitates modification of the field of view (FOV) and resolution simply by changing the microscope objective employed to direct the optical beams to the retina. A prescribed FOV can be achieved by adjusting the distance between the ocular lens and the external objective. The performance of a prototypical system will be characterized using tissue-mimicking phantoms. Subsequently, using live animals, we will demonstrate the ability of our techniques to depict retinal/choroidal micro-circulation and the retinal-pigmented epithelium microstructure as well as functional changes related to altered oxygen satu- ration. Images obtained using the proposed methods will be compared with optical fundus images and histology- based ground truth. Successful completion of the proposed study will establish a basis for developing a versatile system for ophthalmic imaging that can be employed in pre-clinical research using a variety of animal models, and ultimately in clinical imaging.

拟议的研究将评估一种新的全光学光声成像技术的可行性， 采用光折射晶体（PRC），并可能提供解剖和功能图像的 视网膜、脉络膜和视神经的超精细分辨率。视网膜亚结构的详细可视化， 视神经对于评估眼科疾病如糖尿病性视网膜病变（DR）、年龄相关性视网膜病变（ADR）、视网膜病变（ADR）和视网膜病变（ADR）是至关重要的。 黄斑变性（AMD）和青光眼。然而，血管功能和局部氧气输送也是 疾病状态的相关指标。现有的诊断模式，如光学相干断层扫描 (OCT)而超声（US）不提供此信息。 我们基于PRC的派实施将解决其他成像方式的缺点，同时提供 亚微米的图像分辨率和是OCT的3至5倍的成像深度。此外，派还可以 提供诸如血红蛋白-氧饱和度水平的功能信息，这可以改善临床 评估眼科疾病。我们的方法不需要流体耦合或物理接触， 我们由于所提出的派的全息实现采用连续波激光器和基于CCD的 用于检测光声（PA）信号的全场干涉测量法，其潜在地可以在500 ms（仅受摄像机帧速率和PA信号检测所需带宽的限制）。CCD- 基于的实现方式还便于简单地通过改变视场（FOV）和分辨率来修改视场和分辨率。 用于将光束导向视网膜的显微镜物镜。可以实现规定的FOV 通过调节目镜透镜和外部物镜之间的距离。 原型系统的性能将使用组织模拟体模进行表征。随后，委员会注意到， 使用活体动物，我们将证明我们的技术描绘视网膜/脉络膜微循环的能力 视网膜色素上皮的显微结构以及与氧饱和度改变相关的功能变化， 定量配给。使用所提出的方法获得的图像将与眼底图像和组织学进行比较， 基于Ground Truth成功完成拟议的研究将为发展一个多功能的 用于眼科成像的系统可以在使用各种动物模型的临床前研究中使用， 最终应用于临床成像。