A. Hackmann et al., EXTENSION OF THE RORSCHACH-HAZLEWOOD THEORETICAL-MODEL FOR SPIN-LATTICE RELAXATION IN BIOLOGICAL-SYSTEMS TO LOW-FREQUENCIES, Journal of magnetic resonance. Series B, 110(2), 1996, pp. 132-135
The water-biopolymer cross-relaxation model, proposed by H. E. Rorscha
ch and C. F. Hazlewood (RH) [J. Magn. Reson. 70, 79 (1986)], explains
the Larmor frequency dependence of T-1 in many biological systems. How
ever, the RH theory fails at low Larmor frequencies, In this paper, a
more general version of the RH theory has been developed. This theory
is valid at all frequencies. Use of the new expression for the spin-la
ttice relaxation rate (1/T-1), earlier published experimental data in
H2O/D2O bovine serum albumin, which had been measured over a wide freq
uency range (10 kHz to 100 MHz), were fitted over the entire frequency
range, The agreement between theory and the experimental data is exce
llent, Theoretical expressions for the rotating-frame spin-lattice rel
axation rate (1/T-1 rho) were also obtained. (C) 1996 Academic Press,
Inc.