Ultrasonic-tagged remote interferometric flowmetry for brain activity

用于大脑活动的超声波标记远程干涉流量测量

• 批准号: 10731255
• 负责人: Min Xu
• 金额: $ 22.41万
• 依托单位: HUNTER COLLEGE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10731255
• 关键词: Address; Blood; Blood flow; Brain; Brain imaging; Caring; Cerebrovascular Circulation; Cerebrovascular Disorders; Cerebrum; Cognitive aging; Detection; Diffusion; Flowmetry; Focused Ultrasound; Functional Magnetic Resonance Imaging; Goals; Holography; Human; Image; Laser Speckle Imaging; Lasers; Light; Lighting; Measurement; Measures; Metabolic; Methods; Monitor; Monte Carlo Method; Nature; Noise; Optical Methods; Optics; Outcome; Oxygen; Performance; Photons; Process; Research; Research Design; Resolution; Scheme; Signal Transduction; Site; Spectrum Analysis; Structure; Technology; Tissue imaging; Tissues; Ultrasonics; Variant; Work; absorption; biological systems; blood flow measurement; blood oxygen level dependent; brain size; cerebrovascular health; cost; detection method; electric field; experimental study; hemodynamics; heterodyning; imaging platform; innovation; metabolic rate; millimeter; neural; neuroimaging; non-invasive imaging; novel; portability; quantum; real time monitoring; ultrasound; uptake

Optical monitoring of brain activities is intrinsically associated with various operational advantages, including low-cost and portable noninvasive bedside continuous monitoring capabilities. While the preva- lent optical brain monitoring methods are based on measuring blood oxygenation level-dependent (BOLD) signals from blood absorption, optical methods measuring cerebral blood flow (CBF) from the decor- relation of coherent light when scattered by the blood flow may provide a promising alternative. CBF measurement has higher sensitivity to the brain and is complementary to BOLD signals. Their combi- nation can provide a more precise picture of neural activity and may be, for example, used to compute the metabolic oxygen uptake rate in the brain. Noninvasive CBF measurement is also instrumental for functional neuroimaging of the human brain for cerebrovascular health, cognitive aging, and neuroin- tensive care. However, the current optical CBF detection methods, such as diffusion correlation spec- troscopy (DCS), laser speckle-based imaging, and their variants, are prone to extracerebral contami- nation. They are limited in depth sensitivity relying on the distribution of the photon paths. For this R21 project, we propose to develop and evaluate a novel CBF measurement method, known as ultrasonic- tagged remote interferometric flowmetry (URIF), for the task of high sensitivity and selectivity brain activ- ity monitoring. URIF is substantially different from current optical CBF methods. Whereas current optical CBF methods measure an integrated signal from all optical paths in which the signal photons that have passed through the brain activity site are overwhelmed by non-signal photons that have not, URIF se- lects and coherently amplifies only the signal photons through ultrasonic tagging and heterodyne detec- tion. More importantly, with a novel theoretical and experimental framework, URIF can quantify the local CBF at the millimeter-size brain activity site at depths reaching one centimeter and beyond, removing ex- tracerebral contamination and significantly enhancing depth sensitivity, selectivity, and spatial resolution. Local absorption variation associated with hemodynamics can also be monitored simultaneously. We propose first to develop URIF using single-shot off-axis holography and then numerically and experimen- tally validate URIF on human brain phantoms. The performance metrics of URIF for measuring deep flow will be determined in terms of accuracy, sensitivity, and selectivity. If successful, the technology will pave a novel avenue for remote flowmetry of brain activity and fill a vital measurement gap that existing optical and non-optical methods have not been able to address.

大脑活动的光学监测与各种操作优势本质上相关， 包括低成本和便携式无创床旁连续监测功能。而preva- 借出的光学大脑监测方法基于测量血液氧合水平依赖性（粗体） 来自吸血的信号，光学方法测量装饰的脑血流（CBF） - 当血流散射时相干光的关系可能提供有希望的选择。 CBF 测量对大脑具有更高的敏感性，并且与大胆信号互补。他们的组合 民族可以提供更精确的神经活动图片，例如，可能用于计算 大脑中的代谢氧摄取速率。无创CBF测量也有助于 人脑的功能性神经影像学用于脑血管健康，认知衰老和神经素 - 潮流护理。然而，当前的光学CBF检测方法，例如扩散相关表格 - Troscopy（DC），基于激光斑点的成像及其变体，容易发生脑外污染 国家。它们依赖于光子路径的分布的深度灵敏度受到限制。对于此R21 项目，我们建议开发和评估一种新型的CBF测量方法，称为超声波 标记的远程干涉流量计（URIF），用于高灵敏度和选择性大脑活动的任务 - 监视。 URIF与当前的光学CBF方法大不相同。而电流光学 CBF方法测量来自所有光学路径的集成信号，其中具有的信号光子具有 通过大脑活动部位通过的非信号光子淹没了 Lects并相干地仅通过超声标记和杂作检测来放大信号光子 tion。更重要的是，有了一个新颖的理论和实验框架，乌里夫可以量化本地 毫米大小的大脑活动部位的CBF深度达到一厘米及以后，去除 trac骨污染，并显着增强深度灵敏度，选择性和空间分辨率。 与血液动力学相关的局部吸收变异也可以同时监测。我们 首先提出使用单次轴外全息图开发乌里夫，然后在数值和实验中开发 TALLY验证乌里夫在人脑幻象上。乌里夫（Urif）的性能指标 流程将根据准确性，灵敏度和选择性确定。如果成功，技术将 铺平远程流动式大脑活动流程的新颖途径，并填补存在的重要测量空白 光学和非光学方法无法解决。