Spin echo spectroscopic electron paramagnetic resonance imaging.
The use of spin echoes to obtain spectroscopic EPR images (spectral-spatial images) at 250 MHz is described. The advantages of spin echoes-larger signals than the free induction decay, better phase characteristics for Fourier transformation, and decay shapes undistorted by instrumental dead time-are clearly shown. An advantage is gained from using a crossed loop resonator that isolates the 250-W pump power by greater than 50 dB from the observer arm preamplifiers. The echo decay rates can be used to determine the oxygen content in solutions containing 1 mM trityl concentrations. Two- and three-dimensional images of oxygen concentration are presented.
Mailer
Colin
C
Center for EPR Imaging In Vivo Physiology, Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois 60637, USA. cmailer@rover.uchicago.edu
Sundramoorthy
Subramanian V
SV
Pelizzari
Charles A
CA
Halpern
Howard J
HJ
D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005583:Fourier Analysis; D010100:Oxygen / Q000737:chemistry; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels; D014320:Triphenylmethyl Compounds / Q000737:chemistry*
D013113:Spin Labels; D014320:Triphenylmethyl Compounds; D010100:Oxygen