Collaborative Research: IDBR: TYPE A: Unconventional Antenna Probes for Ultra-High-Resolution Magnetic Resonance Imaging

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Magnetic Resonance Imaging (MRI) facilities with enhanced spatial resolution and reduced scan time are in urgent demand for investigating a comprehensive range of biological systems from single cells to humans. The main advantage of high-field MRI scanners is their potential to provide improved anatomic and temporal resolution. Over the past decade, the magnetic field of clinical scanners has increased from 1.5 Tesla (T) to 3 T, revolutionizing functional MRI to map the brain activity. Higher image resolution may also eliminate the need for chemical contrast agents injected in the body and allow for earlier detection of disease. Recently, 9.4 T MRI scanners have been explored for the human anatomy studies. Additional advancements are anticipated for animal and plant imaging, which will be carried out in 7 T to 20 T MRI scanners. Cell imaging will be possible for the micron scale resolutions that are achieved with 11.7 T and higher field scanners. The performance of conventional coil probes, however, degrades at the higher frequencies required by high-field MRI systems, therefore, new high-frequency MRI probes are needed. This research will address fundamental electromagnetic challenges of high-resolution MRI by developing unconventional antenna probes for high-field MRI scanners to replace standard radio frequency coils. The results of the project will enhance the capabilities of high-field MRI and have an immediate impact on ongoing studies in animal behavior. Researchers of biological anthropology, fisheries and biology will benefit from new tools with shorter scan times and higher resolution. This work will also open the paths for new antenna probes for human and clinical MRI.This collaborative effort between the groups from the Electrical and Computer Engineering Department (Michigan Tech University), the Materials Research Institute ((Penn State University), and the Huck Magnetic Resonance Center (Penn State University) will explore a new approach to integrating antenna and MRI technologies, and propose novel patch antenna probes miniaturized by using gradient index metamaterials as a solution for antenna compatibility with MRI environment. Novel antenna probes will provide such advantages for high MRI frequencies as low loss, high Q factor and strong signal due to optimized coupling between patch and feeding systems that will increase image volume resolution by a factor of 10 over that of the present-day coils in a 20 T MRI scanner. The project includes computational electromagnetic modeling, design, and optimization of antenna probes; engineering composite dielectric substrates and fabricating antenna systems; and testing probes at the antenna facilities and in MRI scanners on phantoms and biological samples. The probes will be directly tested in biological research: the brain development of zebrafish will be initially explored as a model for other systems. The size flexibility of novel antennas will provide for customized volumes of uniform radio frequency field and allow for analyzing diverse samples including mice and single cells. There are outstanding opportunities for the broad and immediate dissemination of the project results through the Penn State's Center for MRI, which is a shared-use facility for all departments including anthropology and bioengineering, the Hershey Medical Center, and the NSF supported Center for Dielectric Studies comprised of industrial companies.