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DOI: 10.1055/s-0039-1683637
Continuous Blood-Sampling in small animal [18F]FDG-PET/CT measurements
Publikationsverlauf
Publikationsdatum:
27. März 2019 (online)
Ziel/Aim:
Small animal positron emission tomography/computed tomography (PET/CT) is an important preclinical tool to analyze disease mechanisms. Alterations in glucose utilization are associated with neurodegeneration and can be measured in [18F]FDG-PET/CT studies. Current analyzing strategies for small animal [18F]FDG-PET/CT Data do not facilitate full quantification as kinetic information of the blood radioactivity is usually missing. A continuous measurement of the blood tracer concentration might enable quantification but is technically challenging.
Methodik/Methods:
Hemiparkinsonism (Hemi-PD) was unilaterally induced in Wistar rats. 24 microgram of the toxin 6-OHDA were injected into the right medial forebrain bundle (hemi-PD rats, n = 10). Control animals were injected with carrier solution (n = 9). Before the PET/CT scan an arteriovenous (a-v) shunt was positioned between arteria and vena femoralis. The tracer [18F]FDG was injected into the a-v shunt and a dynamic PET/CT measurement was performed over 60 min. The time-course of radioactivity in blood (arterial input curve) was measured simultaneously to the PET/CT scan via the a-v shunt using a detector pump system (Twilight, Swisstrace). Standardized Uptake Values (SUVs) in the striatum were calculated with the software PMOD. In a second approach, kinetic modeling was implemented with the arterial input curve and cerebral metabolic rates (CMRglu) were calculated.
Ergebnisse/Results:
The striatal SUV was (mean ± SD) 1.92 ± 0.43/1.74 ± 0.41 g/ml (left/right hemisphere) in control rats and 2.13 ± 0.41/2.05 ± 0.37 g/ml (left/right hemisphere) in hemi-PD rats. The striatal CMRglu was (mean ± SD) 32.17 ± 8.5/31.53 ± 8.0 mmol/min/100 g (left/right hemisphere) in control rats and 35.05 ± 5.1/32.95 ± 5.2 mmol/min/100 g (left/right hemisphere) in hemi-PD rats. The level of significance p in hemi-PD rats was 0.8714 for SUV values and 0.6749 for CMRglu values.
Schlussfolgerungen/Conclusions:
Quantification of small animal [18F]FDG-PET/CT Data is feasible using an arterial input curve derived by continuous Blood-Sampling. Hemi-PD rats showed a tendency of decreased glucose utilization in the striatum which can be interpreted as a decrease in neuronal activity.
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