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Updated: Jun 21, 2026

Rapid Scan Electron Paramagnetic Resonance Opens New Avenues for Imaging Physiologically Important Parameters In Vivo
Published on: September 26, 2016
Half-life mapping of nitroxyl radicals with three-dimensional electron paramagnetic resonance imaging at an interval
Hideo Sato-Akaba1, Yoko Kuwahara, Hirotada Fujii
1Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan.
Abstract:
This technical note reports a continuous-wave electron paramagnetic resonance (CW-EPR) imager that can visualize the distribution of free radicals with a half-life of subminutes in three-dimensional (3D) space. A total of 46 EPR spectra under magnetic field gradients, called projections, were obtained for image reconstruction at an interval of 3.6 s. A shortened data-acquisition time was achieved with the use of analog signals that drove field gradient coils in the imager. 3D mapping of the half-lives of nitroxyl radicals (4-hydroxyl-2,2,6,6-tetramethyl-piperidinyl-1-oxyl) was demonstrated in their reduction reaction with ascorbic acid. Inhomogeneous half-lives were clearly mapped pixel-by-pixel in a sample tube.
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