NMR relaxometry: Spin lattice relaxation times in the laboratory frame versus spin lattice relaxation times in the rotating frame

Steiner, Emilie; Yemloul, Mehdi; Guendouz, Laouès; Leclerc, Sébastien; Robert, Anthony; Canet, Daniel

doi:10.1016/j.cplett.2010.06.064

Cited by 16 publications

(18 citation statements)

References 25 publications

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“…Such an approach has been advocated a long time ago by Halle (9). Actually, these curves extend from 0 Hz to 400 MHz or more, the very low frequency part being constructed from T 2 and T 1r data (18). The low frequency decay of toluene in the gel phase can be safely attributed to intermolecular dipolar relaxation and, although, in that case, a Lorentzian function is not warranted, some trends can be deduced from that part of the dispersion curve.…”

Section: Resultsmentioning

confidence: 99%

“…The method is quite operative as demonstrated recently for full dispersion curves of 1 H water in a porous medium (17). Actually, these curves extend from 0 Hz to 400 MHz or more, the very low frequency part being constructed from T 2 and T 1r data (18). Indeed, relaxometry can be valuable in a large variety of systems and the experimental and numerical methods presented in this article appear suit-able for extracting information from the relevant dispersion curves.…”

Section: Resultsmentioning

confidence: 99%

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“Relaxometry” experiments and analysis of dispersion curves: An illustrative example of toluene in liquid and in organogel phases

Steiner¹,

Bouguet‐Bonnet²,

Robert³

et al. 2012

Concepts Magnetic Resonance

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At very low or low frequency, the so-called dispersion curves (longitudinal relaxation rate as a function of the measurement frequency) are obtained with a ''relaxometer,'' which is generally run according to the ''field-cycling'' technique. Because of the very poor field homogeneity, relaxation times of a single (broad) signal are measured. When going to higher fields, with standard nuclear magnetic resonance spectrometers (possibly with variable field capacities), different lines are resolved. We show how the relaxation rates pertaining to these lines can be connected to the results obtained via the relaxometer. Among other things, we demonstrate why the magnitude mode (generally used for processing the relaxometer data) must be used with caution when several lines are resolved. Actually, we could obtain accurate 1 H dispersion curves in a very broad frequency range (5 kHz-400 MHz), and we show that a decomposition into several Lorentzian curves proves to be adequate, as far as paramagnetic relaxation due to dissolved oxygen is concerned. The method will be applied i) to nondegassed liquid toluene, ii) to the same solvent involved in the formation of an organogel. In that latter case, a low frequency contribution to the dispersion curve (possibly non-Lorentzian) reveals the part of the solvent within the organogel structure. The algorithm used for analyzing these dispersion curves is described.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“Relaxometry” experiments and analysis of dispersion curves: An illustrative example of toluene in liquid and in organogel phases

Steiner¹,

Bouguet‐Bonnet²,

Robert³

et al. 2012

Concepts Magnetic Resonance

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“…The magnetization then decays, with a time constant known as T 1ρ , the rotating frame spin‐lattice relaxation time. This decay time is often more similar to T 1 than it is to T 2 , meaning that the magnetization persists in the x ‐ y plane for significantly longer while spin locked than it would otherwise.…”

Section: Resultsmentioning

confidence: 95%

Two‐pulse frequency‐hopped excitation

Michal

Dong

2016

Concepts Magnetic Resonance

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The use of frequency-hopped pulse pairs and pulse pair trains for exciting NMR signals is introduced. Pairs of pulses, each pair lasting one nutation period about the effective field in the rotating frame, can be used to efficiently tip nuclear spin magnetization. In the limit where the frequency difference between the partners in a pair is large, the magnetization dynamics mimic those of an ordinary rectangular rf pulse with rf amplitude scaled down by a factor of p/2. When the amplitude of the applied rf begins to approach the offset frequency however, the excitation bandwidth broadens dramatically in a manner reminiscent of a composite pulse.The effects of the frequency-hopped pulse pairs is described with analytical calculations and numerical simulations, and are shown to agree well with experiment.

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“…The spectra obtained with each pulse sequence (CPMG, PROJECT, and T 1ρ ) have the same filtration effect, but the profiles show predictable intensity differences due to the different mechanisms involved in each relaxation filter. 65 The impact of these differences on the statistical processing obviously depends on the reproducibility of the artefacts of each sequence and on the modulations (e.g., due to exchange phenomena), resulting from the adaptation of the inter-pulse delays to the rotation frequency ν r . Another important experimental consideration for T 1ρ is to avoid the synchronization of the spinning frequency ν r with the spin-lock frequency ν 1 .…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Evaluation of the Rotating-Frame Relaxation (T_1ρ) Filter and Its Application in Metabolomics as an Alternative to the Transverse Relaxation (T₂) Filter

et al. 2021

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Nuclear magnetic resonance (NMR)-based metabolomic studies commonly involve the use of T 2 filter pulse sequences to eliminate or attenuate the broad signals from large molecules and improve spectral resolution. In this paper, we demonstrate that the T 1ρ filter-based pulse sequence represents an interesting alternative because it allows the stability and the reproducibility needed for statistical analysis. The integrity of the samples and the stability of the instruments were assessed for different filter durations and amplitudes. We showed that the T 1ρ filter pulse sequence did not induce sample overheating for a filter duration of up to 500 ms. The reproducibility was evaluated and compared with the T 2 filter in serum and liver samples. The implementation is relatively simple and provides the same statistical and analytical results as those obtained with the standard filters. Regarding tissues analysis, because the duration of the filter is the same as that of the spin-lock, the synchronization of the echo delays with the magic angle spinning (MAS) rate is no longer necessary as for T 2 filter-based sequences. The results presented in this article aim at establishing a new protocol to improve metabolomic studies and pave the way for future developments on T 1ρ alternative filters, in liquid and HR-MAS NMR experiments.

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NMR relaxometry: Spin lattice relaxation times in the laboratory frame versus spin lattice relaxation times in the rotating frame

Abstract: (EA 3440) Faculté des Sciences et Technologies BP 70239 54506 Vandoeuvre-lès-Nancy (cedex), France

Cited by 16 publications

References 25 publications

“Relaxometry” experiments and analysis of dispersion curves: An illustrative example of toluene in liquid and in organogel phases

“Relaxometry” experiments and analysis of dispersion curves: An illustrative example of toluene in liquid and in organogel phases

Two‐pulse frequency‐hopped excitation

Evaluation of the Rotating-Frame Relaxation (T_1ρ) Filter and Its Application in Metabolomics as an Alternative to the Transverse Relaxation (T₂) Filter

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NMR relaxometry: Spin lattice relaxation times in the laboratory frame versus spin lattice relaxation times in the rotating frame

Abstract: (EA 3440) Faculté des Sciences et Technologies BP 70239 54506 Vandoeuvre-lès-Nancy (cedex), France

Cited by 16 publications

References 25 publications

“Relaxometry” experiments and analysis of dispersion curves: An illustrative example of toluene in liquid and in organogel phases

“Relaxometry” experiments and analysis of dispersion curves: An illustrative example of toluene in liquid and in organogel phases

Two‐pulse frequency‐hopped excitation

Evaluation of the Rotating-Frame Relaxation (T1ρ) Filter and Its Application in Metabolomics as an Alternative to the Transverse Relaxation (T2) Filter

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Product

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About

Evaluation of the Rotating-Frame Relaxation (T_1ρ) Filter and Its Application in Metabolomics as an Alternative to the Transverse Relaxation (T₂) Filter