Advanced Analysis of Functional Magnetic Resonance Imaging (MRI) Data for Evaluation of Tissue Physiology

用于评估组织生理学的功能磁共振成像 (MRI) 数据的高级分析

• 批准号: 238588-2012
• 负责人: Noseworthy, Michael
• 金额: $ 2.26万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=524381
• 关键词: Advanced; Analysis; Functional; Magnetic; Resonance

Previous work done in my lab, using funding from 2 consecutive NSERC Discovery grants, has focused on the evaluation of microcirculation using magnetic resonance imaging (MRI). My previous published work has shown how pharmacokinetic models of dynamic contrast enhanced MRI (dceMRI) are overly simplistic: In rabbits MRI contrast agents become internalized inside endothelial cells, and supposed 'contrast equilibrium' between the extra and intravascular space varies between tissues and is more temporally complex than previously assumed. This led me to investigate non-contrast agent based approaches using MRI blood-oxygen level dependent (BOLD) imaging, the basis behind brain functional MRI (fMRI). BOLD image contrast varies due to modulation in the ratio of oxy- to deoxyhaemoglobin. If tissue metabolism can somehow be changed, be it through normal physiological mechanisms, or through pharmacological perturbations, it is a candidate for assessment using BOLD imaging. The overlying purpose of the proposed project is to continue study on microvasculature using non-invasive MR imaging methods. However, the current direction is now to focus on human imaging, before and after some form of physiological perturbation, with signal processing approaches (e.g. Fourier and Wavelet methods), data driven methods (e.g. principle and independent component analysis, i.e. PCA and ICA), and temporal fractal dimension (FD) analysis. In my lab we have successfully assessed the feasibility of this method in skeletal muscle, liver, kidney, various forms of cancer (breast, rectum, prostate) and in Alzheimer's disease. The proposed project will involve evaluation of a number of normal physiological manipulations in healthy human kidney, liver, and skeletal muscle. Furthermore, investigation of physiological mechanism(s) underlying the BOLD signal change(s) will be provided through measurement of blood flow using the MRI technique arterial spin labeling (ASL).

我的实验室之前使用连续两次 NSERC Discovery 资助的资金完成的工作重点是使用磁共振成像 (MRI) 评估微循环。我之前发表的工作表明，动态对比增强 MRI (dceMRI) 的药代动力学模型过于简单化：在兔子中，MRI 对比剂在内皮细胞内内化，血管外空间和血管内空间之间假定的“对比平衡”在组织之间有所不同，并且比之前假设的在时间上更加复杂。这促使我研究使用 MRI 血氧水平依赖 (BOLD) 成像的非造影剂方法，这是脑功能 MRI (fMRI) 背后的基础。 BOLD 图像对比度因氧合血红蛋白与脱氧血红蛋白比例的调节而变化。如果组织代谢能够以某种方式改变，无论是通过正常的生理机制，还是通过药理学扰动，它都是使用 BOLD 成像进行评估的候选者。该项目的首要目的是继续使用非侵入性磁共振成像方法研究微脉管系统。然而，目前的方向是关注某种形式的生理扰动之前和之后的人体成像，采用信号处理方法（例如傅里叶和小波方法）、数据驱动方法（例如原理和独立分量分析，即PCA和ICA）以及时间分形维数（FD）分析。在我的实验室中，我们成功评估了这种方法在骨骼肌、肝脏、肾脏、各种形式的癌症（乳腺癌、直肠癌、前列腺癌）和阿尔茨海默病中的可行性。拟议的项目将涉及对健康人类肾脏、肝脏和骨骼肌的一些正常生理操作的评估。此外，将通过使用 MRI 技术动脉自旋标记 (ASL) 测量血流量来研究 BOLD 信号变化背后的生理机制。