Pulse techniques for the suppression of individual components in multiexponential relaxation curves

NMR pulse sequences have been investigated which selectively suppress undesired signal components from multiple-exponential spin-spin and spin-lattice relaxation curves. Suppression is achieved by exploiting differences in the relaxation times of sample components. Special attention is devoted to discussion of practical details necessary for implementation of these methods, as well as their relative advantages and disadvantages. The techniques are illustrated using multiple-compartment aqueous phantoms and are then employed in measurements of proton T1 and T2 values for freshly isolated guinea pig lenses immersed in aqueous buffer solutions to prevent dehydration and maintain viability. These methods obviate many of the difficulties inherent in obtaining accurate relaxation times for minor components of multiple-exponential curves and should be useful in many applications of NMR to the study of intact tissue, both in vivo and in vitro.

Study of the water--collagen system by NMR cross relaxation experiments

The present work is a study of cross relaxation between water and collagen by NMR pulse techniques. This cross relaxation experiment is easy to set up for NMR spectrometers and gives further information supplementary to other experiments. Relaxation parameters derived from this method provide a sensitive means of monitoring the hydration-dependent behaviour of different types of collagen.