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Title
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Towards a reproducible protocol for repetitive and semi-quantitative rat brain imaging with -FDG: Exemplified in a memantine pharmacological challenge
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Author
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Abstract
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| The standard uptake value (SUV), commonly used to quantify F-18-FluoroDeoxyGlucose (FDG) uptake in small animal brain PET imaging, is affected by many factors. In this study the influence of fasting times, inter-scan duration and repetitive scanning on the variability of different Shy measures is investigated. Additionally it is demonstrated that these variables could adversely influence the outcome of a pharmacological challenge when not accounted for. Naive Sprague-Dawley rats (n = 20) were randomly divided into five different fasting groups (no fasting up to 24 h of fasting). SUV brain uptake values were reproducible in naive animals when a fasting period of at least 12 h is used and for shorter fasting periods SUV values need to be corrected for the glucose level. Additionally, a separate animal group (n = 6) was sufficiently fasted for 16 h and in a longitudinal setting being scanned six times in three weeks. Especially with short inter-scan durations, increasing glucose levels were found over time which was attributed to increased stress due to repeated food deprivation, altered food intake or scan manipulations. As a result, even with controlled and sufficient fasting, blood glucose levels should be taken into account for data quantification. Strikingly, even the brain activation effects of an NMDA-antagonist challenge with memantine could not be detected in experiments with a short inter-scan duration if glucose levels were not taken into account. Correcting for glucose levels decreases the inter- and intra-animal variability for rat brain imaging. SUV corrected for glucose levels yields the lowest inter-animal variation. However, if the body weight changes significantly, as in a long experiment, quantification based on the glucose corrected percentage injected dose (and not SUV) is recommendable as this yields the lowest intra-animal variation. (C) 2014 Elsevier Inc. All rights reserved. |
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Language
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English
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Source (journal)
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Neuroimage. - New York
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Publication
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New York
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2014
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ISSN
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1053-8119
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DOI
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10.1016/J.NEUROIMAGE.2014.04.004
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Volume/pages
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96
(2014)
, p. 276-287
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ISI
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000338809200025
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Full text (Publisher's DOI)
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Full text (publisher's version - intranet only)
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