Spatiotemporal Measurement of Free Radical Elimination in the Abdomen Using an In Vivo ESR-CT Imaging System

Parallel Coil Resonators for Time-Domain Radiofrequency Electron Paramagnetic Resonance Imaging of Biological Objects

“…The flip angle in a single pulse experiment is given by ϭ ␥B 1 t p , [9] where t p is the RF pulse duration in seconds, B 1 is the RF magnetic field flux density in Gauss, and ␥ is the gyromagnetic ratio, 1.7608 ϫ 10 7 radians/s/G for a g ϭ 2 species. For an 80-W RF pulse (70 ns) corresponding to a 90°pulse delivered to the resonator (matched as a 50-ohm load), the reflected power was measured to be 8 W, which corresponds to a net input of 72 W. The flux density calculated from these values corresponds to a B 1 field of 1.2 G. B 1 can also be calculated from the inductance and the current and is given by B 1 ͑T͒ ϭ current ͑Amp͒ ϫ ͑inductance ͑H͒/coil area ͑m 2 ͒͒.…”

Assessment of Oxidative Stress in the Spontaneously Hypertensive Rat Brain Using Electron Spin Resonance (ESR) Imaging and in Vivo L-Band ESR

“…Furthermore, it is well known that the brain might (8)(9)(10)(11). In addition, significant advances in the field of ESR imaging in recent years have made it possible to visualize the distribution and metabolism of free radicals, and the degree of tissue oxygenation in vivo (12)(13)(14)(15)(16)(17)(18). However, ESR imaging detection of endogenous free radicals has been hampered by the low levels of endogenous free radical and the relatively low sensitivity of the spectrometer.…”

“…Nitroxyl radicals are very useful as exogenous spin probes for measuring free radical distribution, oxygen concentration, and redox metabolism by in vivo ESR in biological systems (12,16,18). It has been reported that nitroxyl radicals lose their paramagnetism through a redox reaction when exposed to a reducing agent in biological systems (19,20).…”

Oxidative Stress Imaging in Live Animals with Techniques Based on Electron Paramagnetic Resonance

“…Two-dimensional images of living mice with carbon-tetrachloride damaged livers have shown much a slower reduction rate in the liver region than in untreated mice (80). An interesting study was performed using 1D imaging of nitroxide reduction in the skin of a living rat.…”