Tailored sinc pulses for uniform excitation and artifact-free radio frequency time-domain EPR imaging

• Published in: Journal of magnetic resonance (1997) Vol. 168; no. 1; pp. 110 - 117
• Main Authors: Devasahayam, N., Murugesan, R., Matsumoto, K., Mitchell, J.B., Cook, J.A., Subramanian, S., Krishna, M.C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2004
• Subjects: Animals; Diagnostic Imaging - methods; Electron Spin Resonance Spectroscopy - instrumentation; Electron Spin Resonance Spectroscopy - methods; Equipment Design; Image Enhancement - methods; Mice; Mice, Inbred C3H; Phantoms, Imaging
• ISSN: 1090-7807; 1096-0856
• DOI: 10.1016/j.jmr.2004.01.016

A method to generate shaped radiofrequency pulses for uniform excitation of electron spins in time-domain radio frequency (RF) electron paramagnetic resonance (EPR) imaging is presented. A commercial waveform generator was integrated with the transmit arm of the existing time-domain RF-EPR spectrometer to generate tailored excitation pulses with sub-nano second resolution for excitation with a 90° flip-angle. A truncated sinc [sin
(
x)/
x] pulse, tailored to compensate for the Q-profile (RF frequency response) of the resonator, was shown to yield images from phantom objects as well as in vivo images, with minimal distortion. These studies point to the advantages in using shaped sinc pulses to achieve improved uniform excitation over a relatively wide bandwidth region in time-domain RF-EPR imaging (RF-FT-EPRI).