Exchange-induced relaxation in the presence of a fictitious field

Dennis J. Sorce; Silvia Mangia; Timo Liimatainen; Michael Garwood; Shalom Michaeli

doi:10.1016/j.jmr.2014.04.019

Exchange-induced relaxation in the presence of a fictitious field

Dennis J. Sorce, Silvia Mangia, Timo Liimatainen, Michael Garwood, Shalom Michaeli

Center for Magnetic Resonance Research

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

In the present study we derive a solution for two site fast exchange-induced relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n = 2 are derived for the fast exchange regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n > 2.

Original language	English (US)
Pages (from-to)	12-16
Number of pages	5
Journal	Journal of Magnetic Resonance
Volume	245
DOIs	https://doi.org/10.1016/j.jmr.2014.04.019
State	Published - Aug 2014

Bibliographical note

Funding Information:
NIH Grants BTRC which is P41 EB015894 , P30 NS057091 , R01 NS061866 , S10 RR023730 , S10 RR027290 . The author S.M. thanks the grant KL2 RR033182 from the National Insititute of Health (NIH) to the University of Minnesota Clinical and Translational Science Institute (CTSI) for support.

Keywords

Exchange
Fictitious fields
High rotating frames
Relaxations

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title = "Exchange-induced relaxation in the presence of a fictitious field",

abstract = "In the present study we derive a solution for two site fast exchange-induced relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n = 2 are derived for the fast exchange regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n > 2.",

keywords = "Exchange, Fictitious fields, High rotating frames, Relaxations",

author = "Sorce, {Dennis J.} and Silvia Mangia and Timo Liimatainen and Michael Garwood and Shalom Michaeli",

note = "Funding Information: NIH Grants BTRC which is P41 EB015894 , P30 NS057091 , R01 NS061866 , S10 RR023730 , S10 RR027290 . The author S.M. thanks the grant KL2 RR033182 from the National Insititute of Health (NIH) to the University of Minnesota Clinical and Translational Science Institute (CTSI) for support. ",

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AU - Sorce, Dennis J.

AU - Mangia, Silvia

AU - Liimatainen, Timo

AU - Garwood, Michael

AU - Michaeli, Shalom

N1 - Funding Information: NIH Grants BTRC which is P41 EB015894 , P30 NS057091 , R01 NS061866 , S10 RR023730 , S10 RR027290 . The author S.M. thanks the grant KL2 RR033182 from the National Insititute of Health (NIH) to the University of Minnesota Clinical and Translational Science Institute (CTSI) for support.

PY - 2014/8

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N2 - In the present study we derive a solution for two site fast exchange-induced relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n = 2 are derived for the fast exchange regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n > 2.

AB - In the present study we derive a solution for two site fast exchange-induced relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n = 2 are derived for the fast exchange regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n > 2.

KW - Exchange

KW - Fictitious fields

KW - High rotating frames

KW - Relaxations

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JF - Journal of Magnetic Resonance

ER -

Exchange-induced relaxation in the presence of a fictitious field

Abstract

Bibliographical note

Keywords

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