Abstract
Being similar to values of saturation transfer ratio (STR) in magnetic resonance imaging (MRI) described in our previous paper, values of equivalent cross-relaxation rate (ECR) correlated well with conditions of water in various copolymer gels composed of any two or three monomers among 2-hydroxyethyl methacrylate (HEMA), glycidyl methacrylate (GMA), N-vinyl-2-pyrrolidinone (N-VP), methyl methacrylate (MMA), and benzyl methacrylate (BMA). The water conditions in these copolymer gels were characterized in terms of not only total also free and constrained water contents in the matrix. The MRI measurement was performed by using an off-resonance saturation pulse under conventional field-echo imaging at frequency apart within ±75 ppm from the water resonance frequency. The ECR values were readily to determine and non-time consuming parameter for cross relaxation rate. Both the STR and ECR values at the frequency offset by 4-ppm were divided the sample gels two classes, which must correspond to hydrophilic or hydrophobic ones. In the case of 4-ppm offset, the ECR values were more sensitive parameters than the STR values for evaluation of water condition in the gels and the sensitivity was nearly equivalent to cross-relaxation rate itself. Moreover the ECR values showed excellent correlation with the HEMA as well as constrained water contents in the series of copolymers. Thus the ECR values in the MRI measurement would be adopted as a novel parameter helpful for molecular/material characterization of synthetic copolymers without invasive process to the samples.
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N. Murase and T. Watanabe, Magn. Reson. Med., 9, 1 (1989).
Y. P. Zhang, R. N. Lewis, and R. N. McElhaney, Biophys. J., 72, 779 (1997).
L. J. Peschier, J. A. Bouwstra, J. de Bleyser, H. E. Junginger, and J. C. Leyte, Biomaterials, 14, 945 (1993).
P. S. Belton, Int. J. Biol Macromol., 21, 81 (1997).
M. C. Vackier, B. P. Hills, and D. N. Rutledge, J. Magn. Reson., 138, 36 (1999).
T. Watanabe, N. Murase, M. Staemmler, and K. Gersonde, Magn. Reson. Med., 27, 118 (1992).
H. Yang and T. Schleich, J. Magn. Reson. B, 105, 205 (1994).
S. Matsushima, F. Sasaki, Y. Kinosada, H. Maeda, M. Sogami, S. Era, Y. Yatabe, S. Miura, H. Ohsaki, J. Sakamoto, Magn. Reson. Imaging, 18, 379 (2000).
S. Matsushima, A. Takasu, Y. Inai, T. Hirabayashi, S. Era, Y. Kinosada, M. Sogami, and Y. Kinosada, Polym. J., 32, 828 (2000).
C. Callicott, J. M. Thomas, and A. W. Goode, Phys. Med. Biol., 44, 1147 (1999).
K. Akasaka, R. Ishima, and S. Shibata, Physica B, 164, 163 (1990).
G. Muelen, Magn. Reson. Med., 6, 355 (1988).
K. Akasaka, J. Magn. Reson., 45, 337 (1981).
S. Era, M. Sogami, Y. Kinosada, S. Matsushima, K. Kato, and N. Nagai, Proc. Int. Workshop Appl. Magn. Reson. Other Spectrosc. Tech. Food Sci. (MRF 97), Abstr., 107 (1997).
M. Sogami, S. Era, T. Koseki, and N. Nagai, J. Pep. Res., 50, 465 (1997).
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Matsushima, S., Takasu, A., Inai, Y. et al. Equivalent Cross-Relaxation Rate in Magnetic Resonance Imaging. A Novel Physical Parameter for Evaluation of Conditions of Water in Synthetic Copolymer Gels. Polym J 33, 236–241 (2001). https://doi.org/10.1295/polymj.33.236
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DOI: https://doi.org/10.1295/polymj.33.236