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Generation and Coherent Control of Pulsed Quantum Frequency Combs
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2D Pulses using spatially dependent frequency sweeping.

Albert Jang1,2,3, Naoharu Kobayashi1, Steen Moeller1

  • 1Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minnesota, USA.

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

This study introduces novel 2D frequency-modulated pulses for magnetic resonance imaging. These pulses achieve spatiotemporal phase coherence and can compensate for field inhomogeneities in a single shot.

Keywords:
MRIchirpfrequency-modulated pulsehyperbolic secantmagnetic field inhomogeneityspatiotemporal encoding

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Area of Science:

  • Magnetic Resonance Imaging
  • Pulse Sequence Design

Background:

  • Achieving phase coherence in MRI is crucial for signal generation.
  • Field inhomogeneities (B1+ and B0) degrade image quality.
  • Current methods often require multiple shots or complex setups.

Purpose of the Study:

  • To develop a method for designing 2D frequency-modulated pulses.
  • To achieve spatiotemporal phase coherence.
  • To compensate for field inhomogeneities in a single-shot excitation.

Main Methods:

  • A k-space based pulse design method was developed.
  • Bloch simulations were performed to model pulse behavior.
  • Phantom experiments validated the pulse performance.

Main Results:

  • 2D frequency-modulated pulses selectively excited a cylindrical region.
  • Experimental verification confirmed B1+ inhomogeneity compensation.
  • Simulations indicated partial B0 inhomogeneity compensation.

Conclusions:

  • 2D frequency-modulated pulses offer a new approach to generate phase coherence sequentially.
  • Their spatiotemporal properties enable single-shot RF field inhomogeneity compensation.
  • Potential exists for compensating static field inhomogeneities.