Dennis J Sorce1, Silvia Mangia1, Timo Liimatainen2, Michael Garwood1, Shalom Michaeli3. 1. Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA. 2. A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. 3. Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA. Electronic address: shalom@cmrr.umn.edu.
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. Published by Elsevier Inc.
In the present study we derive a solution for two site fast exchange-induced relaxation in the presence of a fictitious magnetic field as genen class="Species">rated 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. Published by Elsevier Inc.
Entities:
Keywords:
Exchange; Fictitious fields; High rotating frames; Relaxations
Authors: Timo Liimatainen; Alejandra Sierra; Timothy Hanson; Dennis J Sorce; Seppo Ylä-Herttuala; Michael Garwood; Shalom Michaeli; Olli Gröhn Journal: Magn Reson Med Date: 2011-06-30 Impact factor: 4.668
Authors: Timo Liimatainen; Hanne Hakkarainen; Silvia Mangia; Janne M J Huttunen; Christine Storino; Djaudat Idiyatullin; Dennis Sorce; Michael Garwood; Shalom Michaeli Journal: Magn Reson Med Date: 2014-02-12 Impact factor: 4.668