Quadrupole Relaxation

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Danuta Kruk - One of the best experts on this subject based on the ideXlab platform.

  • multi quantum Quadrupole Relaxation enhancement effects in 209bi compounds
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Hermann Scharfetter
    Abstract:

    1H spin-lattice nuclear magnetic resonance Relaxation experiments have been performed for triphenylbismuth dichloride (C18H15BiCl2) and phenylbismuth dichloride (C6H5BiCl2) in powder. The frequency range of 20–128 MHz has been covered. Due to 1H-209Bi dipole-dipole interactions, a rich set of pronounced Quadrupole Relaxation Enhancement (QRE) peaks (Quadrupole peaks) has been observed. The QRE patterns for both compounds have been explained in terms of single- and double-quantum transitions of the participating nuclei. The analysis has revealed a complex, quantum-mechanical mechanism of the QRE effects. The mechanism goes far beyond the simple explanation of the existence of three Quadrupole peaks for 14N reported in literature. The analysis has been supported by nuclear Quadrupole resonance results that independently provided the 209Bi Quadrupole parameters (amplitude of the Quadrupole coupling constant and asymmetry parameter).

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds con...

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.

  • predicting Quadrupole Relaxation enhancement peaks in proton r 1 nmrd profiles in solid bi aryl compounds from nqr parameters
    2019
    Co-Authors: Christian Gosweiner, Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Markus Bodenler, Hermann Scharfetter
    Abstract:

    We propose a simple method to calculate and predict Quadrupole Relaxation enhancement (QRE) features in the spin-lattice nuclear magnetic Relaxation dispersion (R1-NMRD) profile of protons (1H) in ...

  • Quadrupole Relaxation enhancement and polarisation transfer in dmso solution of bi no3 3 h2o 3 18 crown 6 in solid state
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Martin Schlogl, Hermann Scharfetter
    Abstract:

    1H spin-lattice Relaxation studies have been performed for pure [Bi(NO3)3(H2O)3]*18-crown-6 in powder and its solution in dimethyl sulfoxide (DMSO). The experiments have been carried out in the fre...

Hermann Scharfetter - One of the best experts on this subject based on the ideXlab platform.

  • multi quantum Quadrupole Relaxation enhancement effects in 209bi compounds
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Hermann Scharfetter
    Abstract:

    1H spin-lattice nuclear magnetic resonance Relaxation experiments have been performed for triphenylbismuth dichloride (C18H15BiCl2) and phenylbismuth dichloride (C6H5BiCl2) in powder. The frequency range of 20–128 MHz has been covered. Due to 1H-209Bi dipole-dipole interactions, a rich set of pronounced Quadrupole Relaxation Enhancement (QRE) peaks (Quadrupole peaks) has been observed. The QRE patterns for both compounds have been explained in terms of single- and double-quantum transitions of the participating nuclei. The analysis has revealed a complex, quantum-mechanical mechanism of the QRE effects. The mechanism goes far beyond the simple explanation of the existence of three Quadrupole peaks for 14N reported in literature. The analysis has been supported by nuclear Quadrupole resonance results that independently provided the 209Bi Quadrupole parameters (amplitude of the Quadrupole coupling constant and asymmetry parameter).

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds con...

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.

  • predicting Quadrupole Relaxation enhancement peaks in proton r 1 nmrd profiles in solid bi aryl compounds from nqr parameters
    2019
    Co-Authors: Christian Gosweiner, Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Markus Bodenler, Hermann Scharfetter
    Abstract:

    We propose a simple method to calculate and predict Quadrupole Relaxation enhancement (QRE) features in the spin-lattice nuclear magnetic Relaxation dispersion (R1-NMRD) profile of protons (1H) in ...

  • Quadrupole Relaxation enhancement and polarisation transfer in dmso solution of bi no3 3 h2o 3 18 crown 6 in solid state
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Martin Schlogl, Hermann Scharfetter
    Abstract:

    1H spin-lattice Relaxation studies have been performed for pure [Bi(NO3)3(H2O)3]*18-crown-6 in powder and its solution in dimethyl sulfoxide (DMSO). The experiments have been carried out in the fre...

Ralf Ludwig - One of the best experts on this subject based on the ideXlab platform.

  • rotational correlation times diffusion coefficients and quadrupolar peaks of the protic ionic liquid ethylammonium nitrate by means of 1h fast field cycling nmr relaxometry
    2021
    Co-Authors: Viviane Overbeck, Andreas Appelhagen, Ronja Rosler, Thomas Niemann, Ralf Ludwig
    Abstract:

    Abstract The protic ionic liquid (PIL) ethylammonium nitrate (EAN) is characterized by hydrogen bonding between the N H bonds of the cations and the oxygen atoms of the anions. The three-dimensional H-bond network of EAN very much resembles that of water. Although this first ionic liquid is known for more than 100 years, there is still lack of information about the rotational and translational dynamics, and how both are related to each other. For that purpose, we measured the 1H nuclear magnetic Relaxation dispersion curves (NMRD) of EAN by means of Fast Field Cycling (FFC) NMR relaxometry. We were able to analyze the measured 1H spin-lattice Relaxation rates R1 covering a large temperature range between 248 and 333 K simultaneously. Applying the well-known Bloembergen-Purcell-Pound (BPP) approach, we decomposed the total Relaxation rates into intramolecular and intermolecular contributions, describing the rotational and translational dynamics of the ethylammonium cation. Here, we report rotational correlation times, τR, and translational diffusion coefficients, DT, both derived from the total 1H spin-lattice Relaxation rates as a function of temperature and frequency. Self-diffusion coefficients, DT, were also determined from the total Relaxation rates in the low frequency range, wherein only the intermolecular Relaxation contribution is frequency dependent. Then, DT results from the slope of a linear fit of the spin-lattice Relaxation rate R1 as a function of the square root of frequency, ν. The diffusion coefficients obtained from both methods are in good agreement with self-diffusion coefficients measured by pulsed-field-gradient (PFG) NMR. The rotational correlation times, τR, derived from the intramolecular 1H Relaxation contribution were compared to correlation times obtained from high-field NMR deuteron Relaxation experiments, dielectric spectroscopy (DS) and femto-second-infrared (fs-IR) spectroscopy. For EAN, we also observed a local enhancement of the 1H spin-lattice Relaxation rates R1 at high frequencies. This so-called Quadrupole Relaxation enhancement (QRE) results from the interference of the Zeeman transition energy of the 1H spins and the energy difference of two levels of the Quadrupole 14N nuclei. QRE is usually known for solids, but rarely for the liquid state as observed here for EAN. Overall, we show that FFC relaxometry provides access to rotational correlation times, translational diffusion coefficients and Quadrupole Relaxation enhancement at the same time.

  • deuteron Quadrupole coupling constants and reorientational correlation times in protic ionic liquids
    2016
    Co-Authors: Matthias Strauch, Viviane Overbeck, Annemarie Bonsa, Benjamin Golub, Dirk Michalik, Dietmar Paschek, Ralf Ludwig
    Abstract:

    We describe a method for the accurate determination of deuteron Quadrupole coupling constants χD for N–D bonds in triethylammonium-based protic ionic liquids (PILs). This approach was first introduced by Wendt and Farrar for O–D bonds in molecular liquids, and is based on the linear relationship between the deuteron Quadrupole coupling constants χD, and the proton chemical shifts δ1H, as obtained from DFT calculated properties in differently sized clusters of the compounds. Thus the measurement of δ1H provides an accurate estimate for χD, which can then be used for deriving reorientational correlation-times τND, by means of NMR deuteron Quadrupole Relaxation time measurements. The method is applied to pure PILs including differently strong interacting anions. The obtained χD values vary between 152 and 204 kHz, depending on the cation–anion interaction strength, intensified by H-bonding. We find that considering dispersion corrections in the DFT-calculations leads to only slightly decreasing χD values. The determined reorientational correlation times indicate that the extreme narrowing condition is fulfilled for these PILs. The τc values along with the measured viscosities provide an estimate for the volume/size of the clusters present in solution. In addition, the correlation times τc, and the H-bonded aggregates were also characterized by molecular dynamics (MD) simulations.

Elzbieta Masiewicz - One of the best experts on this subject based on the ideXlab platform.

  • multi quantum Quadrupole Relaxation enhancement effects in 209bi compounds
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Hermann Scharfetter
    Abstract:

    1H spin-lattice nuclear magnetic resonance Relaxation experiments have been performed for triphenylbismuth dichloride (C18H15BiCl2) and phenylbismuth dichloride (C6H5BiCl2) in powder. The frequency range of 20–128 MHz has been covered. Due to 1H-209Bi dipole-dipole interactions, a rich set of pronounced Quadrupole Relaxation Enhancement (QRE) peaks (Quadrupole peaks) has been observed. The QRE patterns for both compounds have been explained in terms of single- and double-quantum transitions of the participating nuclei. The analysis has revealed a complex, quantum-mechanical mechanism of the QRE effects. The mechanism goes far beyond the simple explanation of the existence of three Quadrupole peaks for 14N reported in literature. The analysis has been supported by nuclear Quadrupole resonance results that independently provided the 209Bi Quadrupole parameters (amplitude of the Quadrupole coupling constant and asymmetry parameter).

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds con...

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.

  • predicting Quadrupole Relaxation enhancement peaks in proton r 1 nmrd profiles in solid bi aryl compounds from nqr parameters
    2019
    Co-Authors: Christian Gosweiner, Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Markus Bodenler, Hermann Scharfetter
    Abstract:

    We propose a simple method to calculate and predict Quadrupole Relaxation enhancement (QRE) features in the spin-lattice nuclear magnetic Relaxation dispersion (R1-NMRD) profile of protons (1H) in ...

  • Quadrupole Relaxation enhancement and polarisation transfer in dmso solution of bi no3 3 h2o 3 18 crown 6 in solid state
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Martin Schlogl, Hermann Scharfetter
    Abstract:

    1H spin-lattice Relaxation studies have been performed for pure [Bi(NO3)3(H2O)3]*18-crown-6 in powder and its solution in dimethyl sulfoxide (DMSO). The experiments have been carried out in the fre...

Evrim Umut - One of the best experts on this subject based on the ideXlab platform.

  • multi quantum Quadrupole Relaxation enhancement effects in 209bi compounds
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Hermann Scharfetter
    Abstract:

    1H spin-lattice nuclear magnetic resonance Relaxation experiments have been performed for triphenylbismuth dichloride (C18H15BiCl2) and phenylbismuth dichloride (C6H5BiCl2) in powder. The frequency range of 20–128 MHz has been covered. Due to 1H-209Bi dipole-dipole interactions, a rich set of pronounced Quadrupole Relaxation Enhancement (QRE) peaks (Quadrupole peaks) has been observed. The QRE patterns for both compounds have been explained in terms of single- and double-quantum transitions of the participating nuclei. The analysis has revealed a complex, quantum-mechanical mechanism of the QRE effects. The mechanism goes far beyond the simple explanation of the existence of three Quadrupole peaks for 14N reported in literature. The analysis has been supported by nuclear Quadrupole resonance results that independently provided the 209Bi Quadrupole parameters (amplitude of the Quadrupole coupling constant and asymmetry parameter).

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds con...

  • estimation of the magnitude of Quadrupole Relaxation enhancement in the context of magnetic resonance imaging contrast
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Andreas Petrovic, Rupert Kargl, Hermann Scharfetter
    Abstract:

    Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of 1H Relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the Relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions. It has turned out that the theoretically possible enhancement factors are smaller than those of typical paramagnetic contrast agents, but in turn, the field-selectivity of QRE-based agents makes them extremely sensitive to subtle changes of the electric field gradient in the tissue. So far, QRE has been observed for solids (in most cases for 14N) as a result of very slow dynamics and anisotropic spin interactions, believed to be necessary for QRE to appear. We show the first evidence that QRE can be achieved in solutions of compounds containing a high spin nucleus (209Bi) as the Quadrupole element. The finding of QRE in a liquid state is explained in terms of spin Relaxation theory based on the stochastic Liouville equation. The results confirm the Relaxation theory and motivate further exploration of the potential of QRE for MRI.

  • predicting Quadrupole Relaxation enhancement peaks in proton r 1 nmrd profiles in solid bi aryl compounds from nqr parameters
    2019
    Co-Authors: Christian Gosweiner, Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Markus Bodenler, Hermann Scharfetter
    Abstract:

    We propose a simple method to calculate and predict Quadrupole Relaxation enhancement (QRE) features in the spin-lattice nuclear magnetic Relaxation dispersion (R1-NMRD) profile of protons (1H) in ...

  • Quadrupole Relaxation enhancement and polarisation transfer in dmso solution of bi no3 3 h2o 3 18 crown 6 in solid state
    2019
    Co-Authors: Danuta Kruk, Evrim Umut, Elzbieta Masiewicz, Roland Fischer, Martin Schlogl, Hermann Scharfetter
    Abstract:

    1H spin-lattice Relaxation studies have been performed for pure [Bi(NO3)3(H2O)3]*18-crown-6 in powder and its solution in dimethyl sulfoxide (DMSO). The experiments have been carried out in the fre...