Eddy-current compensated diffusion weighting with a single refocusing RF pulse
نویسندگان
چکیده
منابع مشابه
Eddy-Current-Compensated RF Pulse Design for Parallel Excitation
Introduction: High-performance RF coils and shielded Gradient coils [1] for high or ultra high field MRI often require the use of RF shields that are in close proximity to the imaged volume. These shields can sometimes generate Eddy-Currents that are not adequately compensated for using the pre-emphasis algorithm [2] of the scanner. K-space trajectory measurements [3] can be used to compensate ...
متن کاملDouble-spin-echo diffusion weighting with a modified eddy current adjustment.
Magnetic field inhomogeneities like eddy current-related gradient fields cause geometric distortions in echo-planar imaging (EPI). This in particular affects diffusion-weighted imaging where these distortions vary with the direction of the diffusion weighting and hamper the accurate determination of diffusion parameters. The double-spin-echo preparation often used aims to reduce the cumulative ...
متن کاملAn assessment of eddy current sensitivity and correction in single-shot diffusion-weighted imaging.
Artefacts caused by eddy currents are a major problem in diffusion weighted imaging. This is particularly acute in experiments in which a number of images with differing degrees of diffusion weighting and/or differently oriented diffusion-weighting gradients need to be combined. The echo-planar imaging sequence is particularly sensitive to the effects of residual eddy currents, especially due t...
متن کاملArtifacts Caused by Eddy Current in Diffusion MRI
Magnetic resonance diffusion imaging is potentially an important tool for the noninvasive characterization of normal and pathological tissue. The technique, however, is prone to a number of artifacts that can severely affect its ability to provide clinically useful information. In this study, the problem of eddy current-induced geometric distortions that occur in diffusion images was addressed,...
متن کاملA z-gradient array for simultaneous multi-slice excitation with a single-band RF pulse.
PURPOSE Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS Two different field design methods are formulated to solve for the required curre...
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ژورنال
عنوان ژورنال: Magnetic Resonance in Medicine
سال: 2009
ISSN: 0740-3194,1522-2594
DOI: 10.1002/mrm.21899