The determination of translational diffusion constants in liquid crystals from pulsed field gradient double quantum spin echo decays

Martin, Joel F; Selwyn, Lyndsie S.; Vold, Regitze R.; Vold, Robert L.

doi:10.1063/1.443243

Cited by 72 publications

(26 citation statements)

References 20 publications

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“…The 2 H DQF technique is unique and enables measurement of the diffusion of water in each nerve compartment independently. 2 H diffusion measurements for water in the epineurium, endoneurium and the axon were performed by the following DQF-PGSE sequence: [53][54][55] 90…”

Section: Na In Biological Tissuesmentioning

confidence: 99%

Multiquantum filters and order in tissues

et al. 2001

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In ordered systems, where the molecular motion is anisotropic, quadrupolar and dipolar interactions are not averaged to zero. In such cases, double quantum (DQ) coherences can be formed. This review deals mainly with the effect of anisotropic motion of water molecules and sodium ions in intact biological tissues on 2 H, 1 H and 23 Na NMR spectroscopy and its application to NMR imaging (MRI).Double quantum filtered (DQF) spectra of water molecules and sodium ions were detected in a variety of ordered biological tissues. In collagen-containing tissues such as ligaments, tendons, cartilage, skin, blood vessels and nerves, the DQ coherences are formed as a result of the interaction with the collagen fibers. In red blood cells and presumably also in nerve axons it stems from the interaction with the cytoskeleton.For 23 Na, an I = 3/2 nucleus, the DQ coherences can also be formed in isotropic media. By a judicial choice of the pulse angle in the DQ pulse sequence only the DQ coherences arising from anisotropic motion are detected. For I = 1 nuclei such as 2 H, DQF spectra can be observed only in ordered structures. Thus, the observation of 2 H DQF spectra is an indication of order. The same is true for pairs of equivalent 1 H nuclei.The dependence of the DQF signal on the creation time of the double quantum coherences is characteristic to each tissue and allows signals to be resolved from different tissues by performing the measurements at different creation times. In this way, the 2 H DQF signals of the different compartments of sciatic nerve were resolved and water diffusion in each compartment was studied independently. In the axon, the diffusion was heavily restricted perpendicular to the axon's long axis, a result from which the axon diameter could be deduced. In blood vessel walls, this characteristic enabled the different layers of the vessel to be viewed and studied under strain.For 2 H, a DQF spectroscopic imaging sequence was used to study the orientation of the collagen fibers in the different zones of articular cartilage and bone plug. The effect of pressure on the fibers and their return to equilibrium was studied as well. In blood vessels, a DQF image was obtained and strain maps of the different layers were calculated.The efficiency of the 1 H DQF imaging technique was demonstrated on a phantom of rat tail where only the four tendons were detected at short creation times. 1 H DQF imaging and spectroscopy followed the healing of a rabbit's ruptured Achilles tendon and the results were far more sensitive to the process than conventional imaging. Finally, the method was implemented on a commercial whole body MRI spectrometer. Images of human wrist and ankle showed a positive contrast for the tendons and ligaments, indicating the potential of the method for clinical imaging.

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Section: Na In Biological Tissuesmentioning

confidence: 99%

Multiquantum filters and order in tissues

et al. 2001

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“…The experiment, originally developed for liquid crystals, 34,35 has been subsequently applied successfully in the study of the diffusion coefficient of lactic acid in vivo. 36 A PFG-SE sandwich is inserted in the t 1 period of 1 H DQ experiments.…”

Section: Resultsmentioning

confidence: 99%

Analysis of biofluids and chemical mixtures in non-deuterated solvents with1H diffusion-weighted PFG phase-sensitive double-quantum NMR spectroscopy

Dalvit

Böhlen

1997

NMR Biomed.

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“…The model used here assumes that the NMR response originates from molecules all of the same single kind, with a single line spectrum, and is governed by the generalized Bloch equation [7]. Radiation damping and bulk flow are ignored.…”

Section: Interplay Between Molecular Diffusion and Dipolar Field Effementioning

confidence: 99%

“…Torrey's innovation was the introduction of a diffusion term in the Bloch equation of motion for the position dependent magnetization M r t . When it became necessary to extend Torrey's idea for polyatomic molecules, this was done in a piecewise way, separately for each order of (intramolecular) multiple-quantum coherence (6)(7)(8)(9). In the second section, I propose a direct extension of Torrey's method, leading to the introduction of a diffusion term in an equation of motion of the Bloch-Redfield type.…”

Section: Introductionmentioning

confidence: 99%

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Macroscopic molecular diffusion in liquid NMR, revisited

Jeener

2002

Concepts Magn. Reson.

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This paper has three independent parts. First, Torrey's treatment of molecular diffusion in NMR is directly extended to polyatomic molecules by the introduction of a positiondependent average density operator. Second, some improvement is proposed for the study of "abnormal" diffusion by spin-echo experiments, by directly answering the following question: "Which statistical properties of the molecular motion are directly measured in simple spinecho experiments"? Third, a simple numerical technique is proposed for the prediction of the effects of diffusion in spin echo experiments of the CRAZED type, in which the relevant dipolar field inhomogeneities have the spatial periodicity of the magnetization helix.

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The determination of translational diffusion constants in liquid crystals from pulsed field gradient double quantum spin echo decays

Cited by 72 publications

References 20 publications

Multiquantum filters and order in tissues

Multiquantum filters and order in tissues

Analysis of biofluids and chemical mixtures in non-deuterated solvents with1H diffusion-weighted PFG phase-sensitive double-quantum NMR spectroscopy

Macroscopic molecular diffusion in liquid NMR, revisited

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