Eliminating side excitations in PROPELLER-based 2D-selective RF excitations
نویسندگان
چکیده
منابع مشابه
MR Spectroscopy of Arbitrarily Shaped Single Voxel Using Half-Fourier 2D-Selective RF Excitations Based on a PROPELLER Trajectory
The measured signal in conventional single-voxel proton MR spectroscopy (MRS) is generated by three orthogonal slice-selective excitation pulses. This localization method limits the region of interest to cuboidal shapes. 2D-selective RF (2DRF) excitations [1] can be used to excite arbitrarily shaped regions of interest matching the shape of the target region in order to maximize SNR and minimiz...
متن کاملFast Spin-Echo Imaging of Inner Field-of-Views Using 2D-Selective RF Excitations
Introduction Image blurring due to the signal decay along the echo train as well as the RF energy deposited by the refocusing RF pulses limit the applicability of high turbo factors, i.e. a large number of echoes per shot, in fast spin-echo imaging [1], in particular at higher static magnetic fields. In this work, 2D-selective RF (2DRF) excitations [2,3]are used to focus the field-of-view (FOV)...
متن کاملHadamard Encoding of 2D-Selective RF Excitations for Simultaneous Acquisition of Multiple, Irregularly Shaped Voxel in MR Spectroscopy
Introduction 2D-selective RF (2DRF) [1,2] excitations have been used to acquire single voxel MR spectra of irregularly shaped target regions [3,4] which, compared to conventional localization based on cross-sectional RF excitations, reduces partial volume effects. In this study, it is shown that the SNR efficiency of such approaches can be increased by acquiring multiple, irregularly shaped vox...
متن کاملMR Spectrocopy of Arbitrarily Shaped Single Voxel Using Segmented, Blipped-Planar 2D-Selective RF Excitations with Weighted Averaging
NAA and lactate acquired with (a) cross-sectional RF excitations (63 averages) defining a square of 8x8 mm, i.e. the largest square fitting into the corpus callosum profile, and (b,c) with segmented 2DRF exciting the full corpus callosum profile shown in Fig. 1 with (b) standard averaging, i.e. 9 averages for each of the 7 segments, and (c) weighted averaging with 31 averages for the central k-...
متن کاملSegmented 2D-selective RF excitations with weighted averaging and flip angle adaptation for MR spectroscopy of irregularly shaped voxel.
A weighted averaging scheme with flip angle adaptation is presented for segmented 2D-selective RF excitations and applied to single-line segments of a blipped-planar trajectory. Segments covering the central k-space, i.e. those with significant signal contributions, are averaged more often than the (outer) segments with low RF amplitudes and minor signal contributions. For compensation, these o...
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ژورنال
عنوان ژورنال: Magnetic Resonance in Medicine
سال: 2012
ISSN: 0740-3194
DOI: 10.1002/mrm.24172