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Detection of acute kidney injury with hyperpolarized [ 13 C, 15 N]Urea and multiexponential relaxation modeling
Author(s) -
Grist James T.,
Mariager Christian Østergaard,
Qi Haiyun,
Nielsen Per Mose,
Laustsen Christoffer
Publication year - 2020
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.28134
Subject(s) - relaxation (psychology) , chemistry , renal ischemia , kidney , in vivo , urea , ischemia , nuclear magnetic resonance , spin–lattice relaxation , nuclear medicine , reperfusion injury , medicine , physics , biochemistry , microbiology and biotechnology , biology , nuclear quadrupole resonance
Purpose To assess the utility of Laplacian fitting to describe the differences in hyperpolarized [ 13 C, 15 N]urea T 2 relaxation in ischemic and healthy rodent kidneys. Methods Six rats with unilateral renal ischemia were investigated. [ 13 C, 15 N]Urea T 2 mapping was undertaken with a radial fast spin echo method, with subsequent postprocessing performed with regularized Laplacian fitting. Results Simulations showed that Laplacian fitting was stable down to a signal‐to‐noise ratio of 20. In vivo results showed a significant increase in the mono‐ and decrease in biexponential pools in ischemia reperfusion injury kidneys, in comparison to healthy (14 ± 10% versus 4 ± 2%, 85 ± 10% versus 95 ± 3%; P < .05). Conclusion We demonstrate, for the first time, the differences in multiexponential behavior of [ 13 C, 15 N]urea between the healthy and ischemic rodent kidney. The distribution of relaxation pools were found to be both visually and numerically significantly different. The ability to improve the information level in hyperpolarized MR, by using the relaxation contrast mechanisms is an appealing option, that can easily be adopted in large animals and even in clinical studies in the near future.