Iron fMRI: Improving Sensitivty and localization

描述（由申请人提供）：该资助提案“IRON fMRI in animal models：improving sensitivity and spatial localization”是响应RFA EB-03-002“Systems & Methods for Small Animal Imaging”的R 01申请。虽然通过BOLD fMRI进行的功能性脑映射是人类常用的神经科学技术，但动物模型可以实现更有效的技术，这些技术尚未在人类中使用。特别是，氧化铁造影剂（铁功能磁共振成像）提供了显着的改善功能磁共振成像的灵敏度，似乎提供更好的空间定位比BOLD方法，但遭受比BOLD方法稍慢的时间分辨率。该项目的目标是解决IRON功能磁共振成像在动物模型中应用的主要遗留问题。也就是说，1）在非常高的磁场下，IRON和BOLD功能磁共振成像的相对优点是什么？2）IRON时间响应对快速调制的大脑活动有什么影响？3）血容量是否比BOLD信号产生更好的空间定位？我们的假设是：1）IRON方法将填补高场fMRI的关键作用，提高图像质量而不损失灵敏度，2）智能刺激策略将减轻缓慢的IRON时间响应的缺点，即使是快速刺激调制，和3）IRON方法将改善空间fMRI定位。 检测灵敏度和空间分辨率是在小动物模型中有效的fMRI的最关键的实验因素之一。拟议的实验解决了动物模型中有关IRON fMRI的最重要的剩余问题，这些研究是这种强大技术从临床前研究到临床实用的最终进展的逻辑步骤。

DESCRIPTION (provided by applicant): This grant proposal, "IRON fMRI in animal models: improving sensitivity and spatial localization", is an R01 application in response to RFA EB-03-002, "Systems & Methods for Small Animal Imaging". While functional brain mapping by BOLD fMRI is a common neuroscience technique in humans, animal models enable more effective techniques that are not yet available in humans. In particular, iron oxide contrast agents (IRON fMRI) offer remarkable improvements in fMRI sensitivity, appear to provide better spatial localization than the BOLD method, but suffer a somewhat slower temporal resolution than the BOLD method. The goal of the proposed project is to resolve the principal remaining issues concerning the application of IRON fMRI in animal models. Namely, 1) what are the relative merits and IRON and BOLD fMRI at very high magnetic fields, 2) what implications does the IRON temporal response have for rapidly modulated brain activity, and 3) does blood volume produce significantly better spatial localization than BOLD signal? Our hypotheses are 1) the IRON method will fill a critical role in high field fMRI by improving image quality without a loss of sensitivity, 2) intelligent stimulation strategies will mitigate disadvantages of the slow IRON temporal response even for rapidly stimulus modulations, and 3) the IRON method will improve spatial fMRI localization. Detection sensitivity and spatial resolution are among the most critical experimental factors for effective fMRI in small animal models. The proposed experiments address the most important remaining issues concerning IRON fMRI in animal models, and these studies are a logical step in the eventual progression of this powerful technique from pre-clinical studies to clinical utility.