In biomedical NMR imaging and spectroscopy, the increased NMR sensitivity in high-magnetic-field systems offers improved spatial and temporal resolution, as well as the ability to detect phenomena producing more subtle effects. The ability to usefully visualize biochemical distributions in tissues by MR spectroscopic imaging depends on the spatial resolution of the MR techniques available, and the ability to monitor dynamic biochemical or functional changes by MR techniques depends on the speed of the MR techniques available. The purpose of this technical project is to develop improved methods for rapid MRI, chemical shift (spectroscopic) MR imaging, and functional brain MRI, with spatial and temporal resolution exploiting the sensitivity of the high-field (4.1T) UAB system. Techniques are designed and tested in simulation studies, implemented and tested experimentally with the 4.1T MR system in phantom and volunteer studies, and once established, are incorporated into collaborative research protocols. ? This past year several new techniques were developed, and including (1) a rapid echo-planar imaging (EPI) technique utilizing a novel calibration procedure to prevent image defects in the presence of common and unavoidable imperfections in instrumental performance; (2) a novel processing technique for functional MRI which removes confounding systematic """"""""noise"""""""" due to cardiac, respiratory, and other physiological effects; (3) a dual-echo snapshot spiral MRI technique for separation of activation-related signal changes from flow-related changes in fMRI; and (4) improved techniques for detecting the """"""""Fast Response,"""""""" a small fMRI signal dip occurring promptly following the onset of neuronal processing activity in the brain. The techniques developed here benefit collaborative projects and other technical Core projects of this Resource, and are available for use by other research laboratories. The new fMRI methods promise to improve the quality and sensitivity of functional brain studies. The calibrated EPI technique will provide enhanced rapid imaging capabilities in applications within our Resource core projects as well as collaborative projects.
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