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Effects of isoflurane anesthesia on hyperpolarized 13 C metabolic measurements in rat brain
Author(s) -
Josan Sonal,
Hurd Ralph,
Billingsley Kelvin,
Senadheera Lasitha,
Park Jae Mo,
Yen YiFen,
Pfefferbaum Adolf,
Spielman Daniel,
Mayer Dirk
Publication year - 2013
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.24532
Subject(s) - isoflurane , metabolite , anesthetic , anesthesia , cerebral blood flow , medicine , chemistry , pharmacology
Purpose Commonly used anesthetic agents such as isoflurane are known to be potent cerebral vasodilators, with reported dose‐dependent increase in cerebral blood flow and cerebral blood volume. Despite the widespread use of isoflurane in hyperpolarized 13 C preclinical research studies, a quantitative assessment of its effect on metabolic measurements is limited. This work investigates the effect of isoflurane anesthesia dose on hyperpolarized 13 C MR metabolic measurements in rat brain for [1‐ 13 C]pyruvate and 2‐keto[1‐ 13 C]isocaproate. Methods Dynamic 2D and 3D spiral chemical shift imaging was used to acquire metabolic images of rat brain as well as kidney and liver following bolus injections of hyperpolarized [1‐ 13 C]pyruvate or 2‐keto[1‐ 13 C]isocaproate. The impact of a “low dose” vs. a “high dose” of isoflurane on cerebral metabolite levels and apparent conversion rates was examined. Results The cerebral substrate signal levels, and hence the metabolite‐to‐substrate ratios and apparent conversion rates, were found to depend markedly on isoflurane dose, while signal levels of metabolic products and their ratios, e.g. bicarbonate/lactate, were largely insensitive to isoflurane levels. No obvious dependence on isoflurane was observed in kidney or liver for pyruvate. Conclusion This study highlights the importance of careful attention to the effects of anesthesia on the metabolic measures for hyperpolarized 13 C metabolic imaging in brain. Magn Reson Med, 70:1117–1124, 2013. © 2012 Wiley Periodicals, Inc.