Technology Development for Whole Brain Functional and Structural Connectivity Mapping at 10.5T - Since its introduction, MRI has been a transformative tool in medicine and biomedical research. Beyond its remarkable contributions to imaging advancements, significant national resources have recently been directed toward utilizing MRI to investigate neuropsychiatric disorders in the human brain. Two notable initiatives in this area are the Human Connectome Project (HCP) and the BRAIN Initiative. The primary goal of the HCP is to map the functional and structural connectivity of the entire human brain—using functional MRI (fMRI) and diffusion MRI (dMRI), respectively—at the highest possible resolution. Meanwhile, the BRAIN Initiative focuses on developing cutting-edge technologies and methodologies to drive neuroscience discoveries. Theoretical predictions consistently highlight higher field strengths, particularly ultrahigh field (UHF, 7T and above) MRI scanners, as essential for achieving these ambitious milestones. In this context, the 10.5T scanner at CMRR has revolutionized UHF MRI, demonstrating the immense potential of UHF scanners to push the boundaries of imaging technology. However, despite its promise, the current radiofrequency (RF) and gradient technologies at 10.5T remain suboptimal, limiting the scanner’s ability to reach its full potential. Motivated by the transformative opportunities presented by the 10.5T scanner, particularly in neuroimaging, and leveraging our extensive expertise, this proposal seeks to overcome these technological barriers through innovative solutions targeting ultrahigh-resolution fMRI and dMRI. Our approach focuses on three key aims. Aim 1 seeks to advance RF technology to achieve the theoretically promised signal-to-noise ratio (SNR) while addressing RF excitation challenges at 10.5T. This will involve developing an innovative 80-element, shielded, tight-fitting hybrid array coil that combines loop-dipole designs with high-permittivity materials. The coil will be rigorously characterized for SNR, parallel imaging, and RF shimming performance. Aim 2 aims to develop a novel RF coil safety assessment technique to reduce overly conservative safety factors, thereby increasing input power limits while ensuring patient safety. This includes designing a patient-specific, physics-guided deep learning-based method to predict the safety parameters during scans. Aim 3 focuses on achieving mesoscopic-scale human fMRI and dMRI with unprecedented resolutions, including isotropic resolutions of 0.46 mm and 0.63 mm for whole-brain functional and structural connectivity mapping, respectively, and 0.27 mm for partial-brain fMRI studies. By addressing these critical technological challenges in RF coil design, safety assessments, and imaging protocols, this proposal aims to achieve imaging resolutions that surpass those currently available at 3T and 7T. These innovations will set a new benchmark in neuroimaging, advancing the goals of two major national initiatives—the HCP and the BRAIN Initiative—while unlocking new insights into brain structure and function.
