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Enhanced refocusing of fat signals using optimized multipulse echo sequences.

Publication ,  Journal Article
Stokes, AM; Feng, Y; Mitropoulos, T; Warren, WS
Published in: Magnetic resonance in medicine
April 2013

Endogenous magnetic resonance contrast based on the localized composition of fat in vivo can provide functional information. We found that the unequal pulse timings of the Uhrig's dynamical decoupling multipulse echo sequences significantly alter the signal intensity compared to conventional, equal-spaced Carr-Purcell-Meiboom-Gill sequences. The signal increases and decreases depending on the tissue and sequence parameters, as well as on the interpulse spacings; particularly strong differences were observed in fatty tissues, which have a highly structured morphology and a wide range of chemical shifts and J-couplings. We found that the predominant mechanism for fat refocusing under multipulse echo sequences is the chemical structure, with stimulated echoes playing a pivotal role. As a result, specialized pulse sequences can be designed to optimize refocusing of the fat chemical shifts and J-couplings, where the degree of refocusing can be tailored to specific types of fats. To determine the optimal time delays, we simulated various Uhrig dynamical decoupling and Carr-Purcell-Meiboom-Gill pulse sequence timings, and these results are compared to experimental results obtained on excised and in vivo fatty tissue. Applications to intermolecular multiple quantum coherence imaging, where the improved echo refocusing translates directly into signal enhancements, are presented as well.

Duke Scholars

Published In

Magnetic resonance in medicine

DOI

EISSN

1522-2594

ISSN

0740-3194

Publication Date

April 2013

Volume

69

Issue

4

Start / End Page

1044 / 1055

Related Subject Headings

  • Sensitivity and Specificity
  • Reproducibility of Results
  • Obesity
  • Nuclear Medicine & Medical Imaging
  • Mice
  • Magnetic Resonance Imaging
  • Image Interpretation, Computer-Assisted
  • Image Enhancement
  • Humans
  • Breast
 

Citation

APA
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ICMJE
MLA
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Stokes, A. M., Feng, Y., Mitropoulos, T., & Warren, W. S. (2013). Enhanced refocusing of fat signals using optimized multipulse echo sequences. Magnetic Resonance in Medicine, 69(4), 1044–1055. https://doi.org/10.1002/mrm.24340
Stokes, Ashley M., Yesu Feng, Tanya Mitropoulos, and Warren S. Warren. “Enhanced refocusing of fat signals using optimized multipulse echo sequences.Magnetic Resonance in Medicine 69, no. 4 (April 2013): 1044–55. https://doi.org/10.1002/mrm.24340.
Stokes AM, Feng Y, Mitropoulos T, Warren WS. Enhanced refocusing of fat signals using optimized multipulse echo sequences. Magnetic resonance in medicine. 2013 Apr;69(4):1044–55.
Stokes, Ashley M., et al. “Enhanced refocusing of fat signals using optimized multipulse echo sequences.Magnetic Resonance in Medicine, vol. 69, no. 4, Apr. 2013, pp. 1044–55. Epmc, doi:10.1002/mrm.24340.
Stokes AM, Feng Y, Mitropoulos T, Warren WS. Enhanced refocusing of fat signals using optimized multipulse echo sequences. Magnetic resonance in medicine. 2013 Apr;69(4):1044–1055.
Journal cover image

Published In

Magnetic resonance in medicine

DOI

EISSN

1522-2594

ISSN

0740-3194

Publication Date

April 2013

Volume

69

Issue

4

Start / End Page

1044 / 1055

Related Subject Headings

  • Sensitivity and Specificity
  • Reproducibility of Results
  • Obesity
  • Nuclear Medicine & Medical Imaging
  • Mice
  • Magnetic Resonance Imaging
  • Image Interpretation, Computer-Assisted
  • Image Enhancement
  • Humans
  • Breast