TY - JOUR
T1 - Evaluation and comparison of pulsed and continuous wave radiofrequency electron paramagnetic resonance techniques for in Vivo detection and imaging of free radicals
AU - Yamada, Ken Ichi
AU - Murugesan, Ramachandran
AU - Devasahayam, Nallathamby
AU - Cook, John A.
AU - Mitchell, James B.
AU - Subramanian, Sankaran
AU - Krishna, Murali C.
PY - 2002
Y1 - 2002
N2 - The performance of two electron paramagnetic resonance (EPR) spectrometers/imagers, one configured in pulsed mode and the other in continuous wave (CW) mode, at an operating frequency of 300 MHz is compared. Using the same resonator (except for altered Q-factors), identical samples and filling factors in the two techniques have been evaluated for their potentials and limitations for in vivo spectroscopic and imaging applications. The assessment is based on metrics such as sensitivity, spatial and temporal resolution, field of view, image artifacts, viable spin probes, and subjects of study. The spectrometer dead time limits the pulsed technique to samples with long phase memories (>275 ns). Nevertheless, for viable narrow-line spin probes, the pulsed technique offers better sensitivity and temporal resolution. The CW technique, on the other hand, does not restrict the choice at spin probes. In addition, the phase-sensitive narrow-band detection of the CW technique gives artifact-free images even for large objects. Selected examples illustrating the performance of the CW and pulsed techniques are presented to put the capabilities of the two techniques in perspective.
AB - The performance of two electron paramagnetic resonance (EPR) spectrometers/imagers, one configured in pulsed mode and the other in continuous wave (CW) mode, at an operating frequency of 300 MHz is compared. Using the same resonator (except for altered Q-factors), identical samples and filling factors in the two techniques have been evaluated for their potentials and limitations for in vivo spectroscopic and imaging applications. The assessment is based on metrics such as sensitivity, spatial and temporal resolution, field of view, image artifacts, viable spin probes, and subjects of study. The spectrometer dead time limits the pulsed technique to samples with long phase memories (>275 ns). Nevertheless, for viable narrow-line spin probes, the pulsed technique offers better sensitivity and temporal resolution. The CW technique, on the other hand, does not restrict the choice at spin probes. In addition, the phase-sensitive narrow-band detection of the CW technique gives artifact-free images even for large objects. Selected examples illustrating the performance of the CW and pulsed techniques are presented to put the capabilities of the two techniques in perspective.
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U2 - 10.1006/jmre.2001.2487
DO - 10.1006/jmre.2001.2487
M3 - Article
C2 - 11846586
AN - SCOPUS:0036018863
VL - 154
SP - 287
EP - 297
JO - Journal of Magnetic Resonance
JF - Journal of Magnetic Resonance
SN - 1090-7807
IS - 2
ER -