BACKGROUND AND PURPOSE Magnetic resonance spectroscopy (MRS) constitutes a mainstream technique for characterizing biological samples. Benefiting from the separation of chemical shifts and J couplings, spatially localized two-dimensional (2D) J-resolved spectroscopy (JPRESS) shows better identification of complex metabolite resonances than one-dimensional MRS does and facilitates the extraction...

Enormous progress has been made in the last decade towards elucidating the pathogenesis of human neurodegenerative diseases. The successful characterization of pathogenic mutations in several inherited diseases together with genetic engineering enabled the creation of transgenic and knock-in mouse models of human neurodegenerative diseases, such as Huntington's disease (HD), spinocerebellar ata...

Mitigate B1+ inhomogeneity by the combination of RF shimming and B1+ remapping using nonlinear gradient coils Yi-Cheng Hsu, Ying-Hua Chu, Riccardo Lattanzi, Daniel K Sodickson, and Fa-Hsuan Lin Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medic...

Table 1. Parameters for the AWSOS sequence. Combination of a sodium birdcage coil with a tunable patch antenna for B0 shimming and anatomical localization at 9.4 T Christian C. Mirkes, Jens Hoffmann, G. Shajan, Rolf Pohmann, and Klaus Scheffler High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, Department for Biomedical Magnetic Resonance, University of Tü...

INTRODUCTION – Images obtained with gradient-echo echo planar imaging (GRE-EPI) suffer from magnetic field variations within the brain, such as in regions adjacent to air-tissue interfaces. In these regions, magnetic field inhomogeneities cause spins to dephase more rapidly, resulting in signal dropouts. Thus, conventional GRE-EPI pulse sequences used for dynamic susceptibility-contrast perfusi...

OBJECTIVES To prospectively evaluate the impact of 3.0 T Cardiac MR imaging using dual-source parallel radiofrequency (RF) transmission with patient-adaptive B1 shimming compared with single-source RF transmission in the RF homogeneity, image contrast and image quality. METHODS The study was approved by the local institutional review board, and all subjects provided written informed consent. ...

Purpose: To study the possibilities and limitations of RF phase and amplitude shimming with a standard 2 channel head coil at 7T. Introduction One of the main problems in high field MRI is the reduced SNR and loss in contrast due to inhomogeneous B1 RF transmit fields. Spatial homogeneity is of primary importance for diagnostic imaging. At 3T the homogeneity problem is mainly limited to regions...

Introduction In RF shimming [1,2], a single RF current waveform is modulated in amplitude and phase at each coil of a transmit array, in order to control the distribution of electromagnetic (EM) fields and compensate for B1 inhomogeneities. An algorithm to minimize the specific absorption rate (SAR) for a given target profile using RF shimming has been recently proposed and evaluated in simulat...