Direct physiological assessment of the BOLD calibration methods

BOLD 校准方法的直接生理评估

• 批准号: 8282285
• 负责人: MITSUHIRO FUKUDA
• 金额: $ 22.73万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8282285
• 关键词: Animal Model; Animals; Blood; Blood Vessels; Blood Volume; Brain; Brain Mapping; Breathing; Calibration; Carbon Dioxide; Cerebrovascular Circulation; Cerebrum; Clinical; Diagnosis; Disease; Error Sources; Functional Magnetic Resonance Imaging; Gases; Goals; Gold; Health; Human; Hypercapnia; Hyperoxia; Investigation; Laser Scanning Microscopy; Laser-Doppler Flowmetry; Laws; Lead; Measurement; Measures; Metabolic; Methods; Microelectrodes; Modeling; Outcome; Oxygen; Oxygen measurement, partial pressure, arterial; Physiological; Procedures; Public Health; Research; Stimulus; Stroke; Techniques; Testing; Tissues; Venous; Work; base; blood flow measurement; blood oxygen level dependent; innovation; nervous system disorder; neural stimulation; neurophysiology; patient population; relating to nervous system; response; sensor; treatment planning; tumor; two-photon

DESCRIPTION (provided by applicant): Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) is widely used for non-invasively mapping brain function in research and clinical settings. In contrast, quantitative BOLD fMRI approaches have not completely fulfilled their research and clinical potentials because important and unverified concerns remain regarding the appropriateness and accuracy of the calibration procedure. The objective in this particular application is to examine unverified central assumptions used in the BOLD calibration procedures: 1) CO2 and O2 challenges used for calibration do not alter a cerebral metabolic rate of oxygen (CMRO2) and 2) the changes in cerebral blood volume (CBV), especially venous CBV, are directly related to the changes in cerebral blood flow (CBF) induced by CO2 and O2 challenges. To attain this objective we will use well- established techniques to directly determine the following parameters: 1) ongoing neural activity, vascular oxygen concentration and CBF changes induced by CO2 and O2 challenges for CMR O2 estimates, and 2) changes in CBF and venous CBV induced by CO2 and O2 challenges as well as by neural stimulation to examine the relationship between CBV and CBF. The rationale for the proposed research is that the quantitative assessment of BOLD fMRI requires more comprehensive investigations of CO2 or O2-induced changes in vascular and metabolic neurophysiology. Once the CO2 and O2 challenges are validated as iso- metabolic stimuli and the relationship between venous CBV and CBF is established, these calibration strategies will be readily applicable for the accurate assessment of human brain function in the research and clinical settings. This approach is innovative because it provides a direct and more comprehensive assessment of unverified assumptions for BOLD calibration. The proposed research is significant because it could ultimately lead to the advancement of quantitative fMRI, including CMRO2 estimates, in the diagnosis and treatment planning of diseases that are associated with tumor, stroke and neurological disorders. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because the ultimate establishment of quantitative functional MRI is expected to advance the diagnosis and treatment planning of diseases that are associated with stroke and neurological disorders.

描述（由申请人提供）：血氧水平依赖（BOLD）功能磁共振成像（fMRI）广泛用于研究和临床环境中的非侵入性脑功能测绘。相比之下，定量BOLD fMRI方法并没有完全发挥其研究和临床潜力，因为校准程序的适当性和准确性仍然存在重要且未经验证的问题。在这个特殊的应用中，目的是检验BOLD校准过程中使用的未经验证的中心假设：1)用于校准的CO2和O2挑战不会改变脑氧代谢率（cmoro2）； 2)脑血容量（CBV）的变化，特别是静脉CBV，与CO2和O2挑战引起的脑血流量（CBF）的变化直接相关。为了实现这一目标，我们将使用成熟的技术直接确定以下参数：1)持续的神经活动、血管氧浓度和CBF变化由CO2和O2刺激引起，用于CMR O2估计；2)CBF和静脉CBV的变化由CO2和O2刺激引起，以检查CBV和CBF之间的关系。提出这项研究的基本原理是，BOLD功能磁共振成像的定量评估需要更全面地研究二氧化碳或二氧化碳诱导的血管和代谢神经生理学变化。一旦CO2和O2挑战被证实为等代谢刺激，并且建立了静脉CBV和CBF之间的关系，这些校准策略将很容易适用于研究和临床环境中对人脑功能的准确评估。这种方法是创新的，因为它为BOLD校准提供了对未经验证的假设的直接和更全面的评估。这项拟议的研究意义重大，因为它可能最终导致定量fMRI的进步，包括cmr2的估计，在与肿瘤、中风和神经系统疾病相关的疾病的诊断和治疗计划中。