TRD2: Mapping of Molecular and Physiological Tissue Properties at UHF

ABSTRACT – TRD2 Magnetic resonance imaging and spectroscopy are valuable modalities providing unique information for the molecular and physiological characterization of tissue. The breadth of both endogenous and exogenous molecular imaging contrasts in combination with high resolution functional and anatomic imaging motivate the continued development of the methods, their biomedical applications and clinical translation. The potential to improve MRI sensitivity to markers of molecular dynamics, metabolism, energetics, and critical processes continue to drive the development of MRI methods to higher and higher magnetic fields. The 10.5T whole-body MRI systems in our lab offers a comprehensive imaging platform to provide unprecedented access to molecular and functional information non-invasively. It has been shown that sensitivity, as measured by the signal-to-noise ratio (SNR), scales supralinearly with the static field strength which can be leveraged to increase spatial and/or temporal resolution. To realize these potential gains the need remains for continued innovation with respect to acquisition methods, MRI contrasts, RF management strategies, novel RF hardware, and state of the art reconstruction and quantification approaches. To address this need, the overall goal of this project is to develop novel technologies for ultra-high field applications, with a specific focus on selected methods that will have the greatest impact on the field and advance developments made in the first phase of this NCBIB. To accomplish this goal, we will focus on four areas. First, we will integrate dual-tuned RF coils in a parallel transmit (pTx) enabled multinuclear platform and exploit its functionality through introducing novel RF optimization and acquisition strategies. Second, we will introduce novel rotating frame relaxation (RFR) relaxation metrics and the strategies that allow us to conduct these experiments at UHF. Third, we will develop strategies for obtaining high resolution arterial spin labeling as a biomarker of angiogenesis and an important parameter towards deciphering the neurovascular coupling occurring during brain activation. Fourth, we will explore new post processing methods that work synergistically with UHF to provide minimally biased estimates of quantitative parameters for domain specific applications in the presence of increasing amounts of noise as we push temporal and spatial resolutions. Achieving these aims will advance access to molecular and physiological parameters to characterize tissue, support biomedical research and impact our understanding of the living system in health and disease. The challenges addressed in this project are relevant for all UHF systems including 7T which recently received clinical approval. As such, the impact of the proposed technologies extends well beyond 10.5T.