High-resolution Elastographic Assessment of the Optic Nerve Head

摘要 青光眼是世界范围内导致不可逆转失明的主要原因，影响着超过220万美国人。带着一个 随着人口老龄化，预计到2020年青光眼患者将达到8000万 在全球范围内，有11人双目失明。这项研究的目标是开发一种新的成像和测量工具 无创的视神经头(ONH)和筛板(LC)的弹性特性。为了实现这一目标， 我们建议使用相分辨OCT来检测由声辐射力引起的微小位移 (Arf)在全日制医院。我们还提出了一种新型的工作在4~10 MHz范围内的单晶2D阵列 以产生ARF推力。我们建议使用单晶超声换能器来增加 敏感度。组合后的系统将使我们能够生成描述局部位移的图像 纳米分辨率。使用最先进的数值模型，这些数据将与复杂的 用于确定组织的各向异性、非均匀弹性特性的组织宏观和微观结构 具有高分辨率和高灵敏度的ONH。这将使我们能够详细地描述这种联系 年龄、种族和性别对ONH组织力学性能的影响。我们的具体目标是： 具体目标1：研制用于ARF推力产生的单晶二维超声阵列。 具体目标2：开发集成的2D阵列ARF-光学相干弹性成像(OCE)系统 启用共同配准的OCT、US和ARF-OCE成像。 具体目标3：开发和验证整合目标1和实验数据的数值模型 2测定LC和ONH的局部力学性能。 具体目标4：对人身体和兔眼进行体外弹性成像，以确定其能力 并评估ARF-OCE系统检测ONH和LC组织特性变化的性能 与年龄、性别和物种有关。在人类的眼睛里，我们也会确定由于种族或 疾病之间以及卫生保健机构各地区之间的合作。 具体目标5：在兔眼进行LC和ONH的活体成像，以显示临床前成像能力 使用ARF-OCE系统和优化系统进行体内成像。

Abstract Glaucoma is a leading cause of irreversible blindness worldwide, affecting over 2.2 million Americans. With an aging population, it is estimated that by 2020 the number of people suffering glaucoma will reach 80 million worldwide, with 11 bilaterally blind. The goal of this study is to develop a novel tool for imaging and measuring elastic properties of the optic nerve head (ONH) and lamina cribrosa (LC) non-invasively. To address this goal, we propose to use phase-resolved OCT to detect small displacements induced by acoustic radiation force (ARF) in the ONH. We further propose to build a novel single crystal 2D array operating in the 4~10 MHz range to generate the ARF pushing force. We propose to use single crystal ultrasound transducers for increased sensitivity. The combined system will enable us to generate images depicting local displacements with nanometer resolution. Using state-of-the-art numerical models this data will be integrated with the complex tissue macro and microstructure to determine the anisotropic, inhomogeneous elastic properties of the tissues of the ONH with high resolution and sensitivity. This will allow us to characterize in detail the association between age, race and gender on the mechanical properties of the tissues of the ONH. Our Specific Aims are: Specific Aim 1: Develop single crystal 2D ultrasound array for ARF pushing force generation. Specific Aim 2: Develop an integrated 2D array ARF-Optical coherence elastography (OCE) system that enables coregistered OCT, US, and ARF-OCE imaging. Specific Aim 3: Develop and validate numerical models that integrate the experimental data from Aims 1 and 2 to determine the local mechanical properties of the LC and ONH. Specific Aim 4: Conduct ex-vivo elastography of human cadaveric and rabbit eyes to establish the capability and assess the performance of the ARF-OCE system to detect changes in ONH and LC tissue properties associated with age, gender and species. In human eyes, we will also determine differences due to race or disease and between regions of the ONH. Specific Aim 5: Demonstrate preclinical imaging capability with in-vivo imaging of LC and ONH in rabbit eyes using ARF-OCE system and optimize system for in-vivo imaging.