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Quasi-light Storage for Optical Data Packets
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Array-compressed parallel transmit pulse design.

Zhipeng Cao1,2, Xinqiang Yan1,3, William A Grissom4,5,6,7

  • 1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.

Magnetic Resonance in Medicine
|October 29, 2015
PubMed
Summary
This summary is machine-generated.

This study introduces array-compressed parallel radiofrequency (RF) pulse design, achieving lower excitation errors than existing methods. This new approach optimizes RF pulse performance for parallel imaging applications.

Keywords:
RF pulse designRF shimmingarray compressionkT points pulsesoptimizationparallel transmissionselective excitationsingular value decompositionspokes pulsestailored excitation

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Area of Science:

  • Magnetic Resonance Imaging (MRI)
  • Radiofrequency (RF) Engineering
  • Signal Processing

Background:

  • Parallel transmit (pTx) MRI enables faster imaging and improved quality by using multiple RF coils.
  • Existing array compression strategies for pTx MRI have limitations in optimizing RF pulse performance.
  • Efficient design of RF pulses is crucial for advanced MRI applications.

Purpose of the Study:

  • To develop and evaluate a novel array-compressed parallel RF pulse design method.
  • To compare the performance of array-compressed pulses against existing compression strategies.
  • To assess the efficacy of array-compressed pulse design for various pTx applications.

Main Methods:

  • Proposed array-compressed pulse design as joint optimization of compression weights and virtual array RF pulses.
  • Developed algorithms for accelerated 2D spiral excitation, multislice RF shimming, small-tip-angle kT-points excitation, and slice-selective spokes refocusing.
  • Compared array-compressed designs with four existing strategies via simulations and experiments.

Main Results:

  • Array-compressed pulses consistently achieved the lowest root-mean-square (RMS) excitation error across all tested applications.
  • Optimal performance was achieved without significant increases in RMS RF amplitudes or specific absorption rate (SAR).
  • Multisubject shimming simulations showed array-compressed RF shimming identifies effective, population-wide coil combination weights.

Conclusions:

  • Array-compressed pulse design offers a superior method for optimizing parallel transmit RF pulses.
  • This technique jointly determines optimal compression weights and RF pulses for specific applications.
  • The method holds promise for enhancing performance in diverse parallel transmit MRI scenarios.