Premium
Use of nitroxides for assessing perfusion, oxygenation, and viability of tissues: In vivo EPR and MRI studies
Author(s) -
Gallez Bernard,
Bacic Goran,
Goda Fuminori,
Jiang Jinjie,
O′Hara Julia A.,
Dunn Jeff F.,
Swartz Harold M.
Publication year - 1996
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910350113
Subject(s) - perfusion , electron paramagnetic resonance , in vivo , chemistry , nuclear magnetic resonance , oxygenation , medicine , biology , physics , microbiology and biotechnology
Relative perfusion, pO 2 , and bioreduction were measured simultaneously in wVo in tissues in mice by following changes in the intensity and shape of the EPR spectra of nitroxides injected directly into the tissues, using low frequency (1.1 GHz) localized EPR spectroscopy. Using normal and blood flow restricted gastrocnemius muscles it was shown that the decrease of the EPR signals of the nitroxides in tissues was due principally to perfusion, which redistributed the nitroxides. Changes in pO 2 were reflected by changes of the linewidth; only a perdeuterated nttroxide with a narrow line was an adequate indicator for this parameter. This technique was applied experimental murine tumors (MTG‐B and RIF‐1) to determine the perfusion and pO 2 in these relatively hypoxic model tumor systems. Using the paramagnetic properties of the nitroxides to enhance T 1 ‐weighted MR images, heterogeneity in perfusion in individual tumors was demonstrated.