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PURPOSE To substantially improve spatial localization in magnetic resonance spectroscopic imaging (MRSI) accelerated by parallel imaging. This is important in order to make MRSI more reliable as a tool for clinical applications. METHODS The sensitivity encoding acceleration technique with spatial overdiscretization is applied for the reconstruction of(More)
PURPOSE To improve B0 shimming for applications in high- and ultrahigh-field magnetic resonance imaging and magnetic resonance spectroscopy. METHODS An existing image-based constrained B0 shimming algorithm was enhanced using two techniques: (1) A region of less interest was introduced to control B0 field inhomogeneities in the vicinity of the region of(More)
PURPOSE To compare several different optimization algorithms currently used for localized in vivo B0 shimming, and to introduce a novel, fast, and robust constrained regularized algorithm (ConsTru) for this purpose. METHODS Ten different optimization algorithms (including samples from both generic and dedicated least-squares solvers, and a novel(More)
The low-temperature dielectric relaxation of collagen and elastin was studied over a wide range of hydrations h. The hydration-shell response increases weakly with temperature, is thermally activated, and conforms to energy barrier scaling. This demonstrates the existence of a decoupled, secondary relaxation akin to that in binary structural glasses.(More)
PURPOSE Inhomogeneities of the main magnetic field cause line broadening and location-dependent frequency shifts in brain MRSI. These are often visible despite advanced B0 shimming. The purpose of this work is to propose an advanced B0 correction method that can easily be applied during postprocessing. METHODS A target-driven overdiscrete reconstruction(More)
PURPOSE To calibrate a pre-emphasis to sufficiently compensate eddy currents for application of dynamic shim updating to fMRI without extension of scan times. METHODS Eddy current effects induced into all shim terms up to third-order were characterized by spatiotemporal field monitoring, using a third-order field camera. Pre-emphasis settings were derived(More)
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