The effect of induced field inhomogeneity (IFI) on transverse NMR relaxation of water protons in tissue has been investigated by examining the field dependence of the effective transverse relaxation rates (1/T2 efF) for in vitro canine brain tissue samples. At fields of 0.47, 2.35, 7.05 T (correspon
NMR relaxation of water in hydrogel polymers: A model for tissue
โ Scribed by John C. Gore; Mark S. Brown; Jianhui Zhong; K. Fritz Mueller; William Good
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 395 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0740-3194
No coin nor oath required. For personal study only.
โฆ Synopsis
The NMR relaxation rates ofa class of hydrated polymers (hydrogels) have been investigated over a wide range of frequencies (0.01 to 60 MHz) and compositions. The gels comprise long chains of polytetramethylene oxide diol crosslinked by copolymers of dimethylacrylamide and methylmethacrylate. The longitudinal relaxation rate dispersion curves of these materials are very similar to those shown by human tissues and they can be altered in flexible fashion by changing the polymer content. By substitution of the water by deuterium oxide, the contribution of intermolecular cross-relaxation effects has been shown to account for two-thirds the total water relaxation rate. With their close similarity to tissue relaxation behavior, hydrogels of differing compositions are particularly well-suited to MRI phantoms and test objects. Q 1989 Academic press, Inc.
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