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Perfluorocarbon temperature measurements using 19 F NMR
Author(s) -
Berkowitz Bruce A.,
Handa James T.,
Wilson Charles A.
Publication year - 1992
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.1940050204
Subject(s) - thermocouple , chemistry , atmospheric temperature range , analytical chemistry (journal) , temperature measurement , oxygen , chemical shift , absolute zero , in vivo , nuclear magnetic resonance , work (physics) , fluorine , materials science , thermodynamics , chromatography , organic chemistry , physics , microbiology and biotechnology , biology , composite material
Abstract Measuring the T 1 of the fluorine resonances of perfluorocarbons (PFC) is a unique method for monitoring oxygen tension in vivo. However, because T 1 is also temperature sensitive, error in the p O 2 determination due to animal‐to‐animal temperature variation may arise. Pathophysiologic conditions, such as ischemia, where temperature is not known a priori may also introduce error. Thus, measuring the PFC temperature is clearly desirable in order to correct for tissue temperature variations during the p O 2 determination. Because the fluorine chemical shift of various fluorinated compounds has a significant temperature dependence, we evaluated the effect of temperature on the chemical shift of the fluorine resonances of perfluorotributylamine (FTBA). A linear relationship was found between chemical shift and temperature in vitro . In addition, the relative FTBA chemical shifts were essentially independent of p O 2 . Chemical shift temperature measurements in vivo , obtained from a 10 μL FTBA bubble in the preretinal vitreous space of the rabbit eye, were in good agreement (±0.5 °C) with thermocouple measurements from the same location. Good agreement between the NMR determined temperature and core body temperature was also found. The implication of such temperature measurements for the ultimate accuracy of the p O 2 determination based on PFC T 1 measurements is discussed. To the best of our knowledge, this report describes the first absolute temperature measurement in vivo by NMR.