TRD3: Percutaneous and Interstitial Imaging

项目摘要 TRD3 TRD 3的总体目标是实现先进的OCT成像，具有高分辨率和功能性 动态对比，活体内部，通过窄直径、旋转的探头。仪器和 将开发克服灵活、旋转光纤固有的基本障碍的算法 探测器，以前已经影响了图像质量，并禁止集成功能和 动态对比。 具体目标1解决冠状动脉血流功能成像的需要。在导管里- 基于OCT，侧视光纤探头执行螺旋扫描图案并记录反射率分布 作为每个扫描位置处的深度的函数。对于正常的动脉成像，血液被置换成 注射一种清晰的造影剂。取而代之的是，在没有注入的情况下记录时间序列会迅速产生 与血流有关的波动信号。基于对该信号的准确建模，重建 将开发提取向量血流剖面的算法。得出总体流量提供了一个关键 评价人类冠状动脉粥样硬化性病变的参数。流量也是一个关键因素 内皮功能障碍和动脉粥样硬化形成的因素。能够映射湍流和详细的流动轮廓 为研究动脉粥样硬化的临床前小鼠模型提供了新的途径。 具体目标2探索生物组织的偏振特性。偏振灵敏检测 测量后向散射光的偏振状态。结合两个正交的偏振态， 照明，这提供了组织的偏振特性的完整表征。然而， 旋转的导管和叠加的组织冲击和偏置每个深度的极化状态。一个 提取深度分辨偏振特性的重建策略，包括双折射、光轴 并将发展去极化。偏振对比将有助于区分急性和非急性 慢性血栓，这是深静脉血栓临床治疗中尚未解决的挑战，以及 在动脉粥样硬化中识别不同的斑块类型。 具体目标3回应了临床前小动物研究中基于导管的成像的需求。狭窄 直径可旋转的OCT探头，小到足以进入小动物的血管系统，或成像 通过皮下注射针孔进入的间质组织将被开发出来。微型探头 将补偿由于透明的窄直径护套而产生的散光 旋转探头，实现高质量和紧聚焦。再加上稳定的扫描机制， 将能够对小动物器官的微小解剖进行高分辨率成像。 这些努力结合在一起，将通过提供额外的对比度和 功能参数，并将OCT的应用扩大到以前达不到的组织和器官。

Project Summary TRD 3 The overall goal of TRD 3 is to enable advanced OCT imaging, with high resolution and functional and dynamic contrast, inside the living body, through narrow diameter, rotational probes. Instruments and algorithms will be developed that overcome fundamental barriers, intrinsic to flexible, rotational fiber-optic probes, that have previously compromised image quality and prohibited the integration of functional and dynamic contrast. Specific Aim 1 addresses the need for functional imaging of blood flow in the coronary arteries. In catheter- based OCT a side-looking fiber-optic probe performs a helical scan pattern and records the reflectivity profile as a function of depth at each scan location. For normal imaging of the arteries, the blood is displaced by injecting a clear contrast agent. Recording, instead, time sequences without injection produces a rapidly fluctuating signal related to the blood flow. Based on accurate modeling of this signal, a reconstruction algorithm to extract vectorial blood flow profiles will be developed. Eliciting the overall flow rate offers a key parameter for the assessment of atherosclerotic lesions in human coronary arteries. Flow is also a critical factor in endothelial dysfunction and atherogenesis. The ability to map turbulence and detailed flow profiles offers a new avenue for the study of preclinical mouse models of atherosclerosis. Specific Aim 2 explores the polarization properties of biological tissue. Polarization sensitive detection measures the polarization state of the backscattered light. Combined with two orthogonal polarization states for illumination, this provides a complete characterization of the polarization properties of the tissue. However, the spinning catheter and the superimposed tissue impact and bias the polarization states at each depth. A reconstruction strategy to extract the depth-resolved polarization properties, including birefringence, optic axis and depolarization will be developed. Polarization contrast will help in differentiating between acute and chronic thrombus, which is an unresolved challenge in the clinical management of deep vein thrombosis, and in identifying different plaque types in atherosclerosis. Specific Aim 3 responds to the need for catheter-based imaging in preclinical small animal research. Narrow diameter rotational OCT probes, small enough to access the vascular system in small animals, or image interstitial tissue accessed through the bore of a hypodermic needle will be developed. The miniature probes will compensate the astigmatism originating from the transparent narrow diameter sheath that is protecting the spinning probe, and achieve a high quality and tight focus. Combined with a stable scanning mechanism this will enable high resolution imaging of the minute anatomy in the organs of small animals. Combined, these efforts will improve the diagnostic capability of OCT by providing additional contrast and functional parameters and expand the application of OCT to tissues and organs previously out of its reach.