fMRI Ability to Map Columnar Structures in Humans

在这项资助的前4年里，我们挑战了BOLD功能磁共振成像的极限，达到了亚毫米的水平。 结构（即皮质柱）和动物模型中的层状特异性。在这项工作中，我们 建立了SE BOLD技术在高领域，更适合映射柱状结构， 人类，其中，在一般情况下，在感兴趣的成像区域中不能容易地避开大血管 有时会污染GE BOLD图像。此外，我们采用高场SE BOLD对比度使我们能够探索，除了ODC，人脑中的方向柱， 以前没有被映射过。虽然一些功能磁共振成像研究已经成功地映射了眼优势 由于最初的ODC功能磁共振成像工作在人类超过6年前，已经有非常 直到我们最近的研究才取得了进展。此外，迄今为止还没有研究表明， 用功能性核磁共振成像技术在猴子身上绘制了脑列。这种长时间的沉默不仅反映了 以及低场和/或GE BOLD技术的局限性，但也存在高场引起的技术问题 这最终限制了高场fMRI应用于有限的体积，特别是在人类中。迄今为止 仍然缺乏适用于所有高分辨率人体研究的通用成像策略，因为这取决于 神经科学的问题被问到不同的方法可能更合适。在下一个循环中， 我们希望在我们的发现的基础上，扩展高分辨率人类功能磁共振成像的方法和工具 为进一步研究未开发和/或未知的功能系统或架构铺平道路， 毫米级和亚毫米级。这些努力将通过更大体积的高分辨率来促进 人类的fMRI采集以及高分辨率动物的持续应用和开发 fMRI模型。随着7特斯拉磁铁的扩散，有一个基本的需要，建立方法和 人类功能磁共振成像（在这些临床扫描仪上）的策略，通常基于以下原则， 较高的场提供较高的空间分辨率和空间特异性 表征更高分辨率的功能架构，例如柱或层状连接，或者通常 研究的应用，如静息状态网络或视觉对象识别（尽管面临许多 技术上的限制）。

During the first 4 years of this grant, we have challenged the limits of BOLD fMRI to the level of sub-millimeter structures (i.e. cortical columns) in humans and laminar specificity in the animal model. In this work we established the SE BOLD technique at high fields, to be more suitable for mapping columnar structures in humans, where, in the general case, large vessels cannot be easily avoided in the imaging region of interest and can sometimes contaminate GE BOLD images. Furthermore, our strategy of employing high-field SE BOLD contrast has allowed us to explore, in addition to ODCs, orientation columns in the human brain, which were previously unmapped. Although several fMRI studies have succeeded in mapping ocular dominance columns (ODCs) in humans, since the initial ODC fMRI work in humans over 6 years ago, there has been very little advancement in this pursuit until our recent work. Furthermore, there have been no studies to date that have mapped columns using fMRI in the monkey. This prolonged silence is not only a reflection of the difficulty and limitations of lower field and/or GE BOLD techniques, but also technical issues incurred at high fields which ultimately limit high field fMRI applications to limited volumes, especially in humans. To date, there remains a lack of a general imaging strategy that works for all high resolution human studies, as depending on the neuroscience question being asked different approaches might be more suitable. In the next cycle of this grant we would like to build on our findings and extend the methods and tools for high resolution human fMRI to pave the way for further investigations of unexplored and/or unknown functional systems or architectures at the millimeter and sub-millimeter levels. These endeavors will be facilitated via larger volume high resolution fMRI acquisitions in humans as well as continued application and development of a high resolution animal fMRI model. With the proliferation of 7 Tesla magnets there is a fundamental need to establish methods and strategies for human fMRI (on these clinical scanners) which will generally be predicated on the principle that higher fields provide higher spatial resolutions and spatial specificity and thus the ability to map and/or better characterize higher resolution functional architectures, such as columns or laminar connections, or commonly studied applications such as resting state networks or visual object recognition (despite facing numerous confounds and technical limitations).