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NMR second moment imaging using Jeener-Broekaert dipolar signals.
S Matsui1, S Saito, T Hashimoto
1Institute of Applied Physics, University of Tsukuba, Tsukuba, 305-8573, Ibaraki, Japan. matsui@bk.tsukuba.ac.jp
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|February 5, 2003
Summary
This study introduces a new method for nuclear magnetic resonance (NMR) imaging using the Jeener-Broekaert (JB) dipolar signal. This technique allows for spatially resolved measurements of the JB second moment, offering new contrast for materials imaging.
Area of Science:
- Nuclear Magnetic Resonance (NMR) Spectroscopy
- Materials Science
- Solid-State Physics
Background:
- Conventional NMR imaging often relies on the Zeeman Free Induction Decay (FID) signal.
- Characterizing materials at a microscopic level requires advanced imaging techniques.
- Understanding molecular dynamics and structure is crucial in materials science.
Purpose of the Study:
- To demonstrate the feasibility of imaging the 1H NMR second moment using the Jeener-Broekaert (JB) dipolar signal.
- To introduce a novel contrast mechanism for materials imaging based on the JB second moment.
- To explore the potential of tau dependence in characterizing second moment distributions.
Main Methods:
- Utilized the Jeener-Broekaert (JB) pulse sequence (90°(x)-τ-45°(y)-τ'-45°(y)) to induce the JB dipolar signal.
- Employed the time-suspension magic echo sequence (TREV-16TS) for imaging detection.
- Estimated the local JB second moment, M(2(JB)), from the initial slope of spatially resolved JB dipolar signals.
Main Results:
- Successfully achieved imaging of the 1H NMR second moment using the JB dipolar signal.
- The M(2(JB)) was found to be a weighted powder average of the usual second moment.
- Demonstrated that the tau dependence of M(2(JB)) provides information on crystal orientation and distribution range.
Conclusions:
- The JB dipolar signal offers a viable alternative to the Zeeman FID signal for NMR imaging.
- The tau dependence of M(2(JB)) introduces a new contrast mechanism for materials imaging.
- Preliminary experiments on test samples illustrate the potential of this new imaging approach.
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