Premium
Magnetization transfer imaging in vivo of the rat brain at 4.7 T: Interpretation using a binary spin‐bath model with a superlorentzian lineshape
Author(s) -
Quesson Bruno,
Thiaudière Eric,
Delalande Christophe,
Dousset Vincent,
Chateil JeanFrançois,
Canioni Paul
Publication year - 1997
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910380617
Subject(s) - magnetization transfer , amplitude , nuclear magnetic resonance , corpus callosum , irradiation , chemistry , proton , physics , magnetic resonance imaging , optics , anatomy , nuclear physics , biology , medicine , radiology
Proton magnetization transfer contrast (MTC) imaging, using continuous wave off‐resonance irradiation, was performed on the rat brain in vivo at 4.7 Tesla. The observed MTC was studied in three different brain regions: the corpus callosum , the basal ganglia, and the temporal lobe. By systematically varying the offset frequency and the amplitude of the RF irradiation, the observed signal intensities for each region of interest were modeled using a system including free water and a pool of protons with restricted motions (R. M. Henkelman, X. Huang, Q. Xiang, G. J. Stanisz, SD Swanson, M. J. Bronskill, Magn. Res. Med. 29, 759 (1993)). Most of the relaxation parameters of both proton pools remained fairly constant for the three regions of interest, with a T 2 value of about 9 μs for the immobilized protons, whereas the rate of exchange increased significantly from the temporal lobe to the corpus callosum. The optimal acquisition parameters for the improved MTC under steady‐state saturation were found to be 2–10 kHz offset frequency and 500–800 Hz RF irradiation amplitude. Conversely, an irradiation amplitude of 3 kHz at an offset frequency of 12 kHz is required to minimize the direct effect of off‐resonance irradiation. Such an approach could be extended to human brain imaging with the aim of characterizing tissue‐specific disease.