Basic studies on the equivalent cross-relaxation rate imaging (equivalent CRI) - phantom studies

Citation
M. Sogami et al., Basic studies on the equivalent cross-relaxation rate imaging (equivalent CRI) - phantom studies, NMR BIOMED, 14(6), 2001, pp. 367-375
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Medical Research Diagnosis & Treatment
Journal title
NMR IN BIOMEDICINE
ISSN journal
0952-3480 → ACNP
Volume
14
Issue
6
Year of publication
2001
Pages
367 - 375
Database
ISI
SICI code
0952-3480(200110)14:6<367:BSOTEC>2.0.ZU;2-K
Abstract
We have studied saturation transfer in hydrophilic, cross-linked copolymer gels from irradiated polymer protons to observed water protons, using f(2) (ppm) profiles of [1 - (I-infinity/I-0)], [(I-0/I-infinity) - 1] or 1/T-IS( H2O), where I-0 and I-infinity are the longitudinal magnetization of the ob served water protons before and after long-time f(2)-irradiation on polymer protons, respectively, and 1/T-IS(H2O) is the cross-relaxation rate. (A) [ 1 - (I-infinity/I-0)] (magnetization transfer ratio, MTR) was used in magne tic resonance imaging (MRI) as the MTR imaging. 1/T-IS(H2O) (cross-relaxati on rate) was used in the imaging of the magnetization transfer rate constan t. This method was quite time-consuming compared with MTR imaging. However, f(2) (ppm) profiles of [(I-0/I-infinity) - 1] correlated well with corresp onding profiles of 1/T-IS(H2O), because [(I-0/I-infinity) - 1] is equal to 1/[T-IS(H2O)/T-1(H2O)]. These results lead us to the conclusion that [(I-0/ I-infinity) - 1] might be applicable to cross-relaxation rate (CR)-like ima ging, i.e. equivalent CRI. (B) W (%) (dry weight) profiles of [(I-0/I-infin ity) - 1] and 1/T-IS(H2O), obtained by near-resonance f(2)-irradiation, see m to indicate participation of molecular rigidity and an amount of bound wa ter. However, those values, monitored with off-resonance f(2)-irradiation, seem to be independent of monomer composition and to indicate mainly partic ipation of rigidity, i.e. W (%) of copolymer gels. Copyright (C) 2001 John Wiley & Sons, Ltd.