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Quantification of [ 11 C]FLB 457 binding in the human brain with PET before and after PVE correction. HBM2004 Satellite meeting. Judit S óvágó Karolinska Institutet Department of Clinical Neuroscience. The influence of PVE on estimates of radioligand uptake.
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Quantification of [11C]FLB 457 binding in the human brain with PET before and after PVE correction HBM2004 Satellite meeting Judit Sóvágó Karolinska Institutet Department of Clinical Neuroscience
The influence of PVE on estimates of radioligand uptake Signal under- or overestimation due to PVE • BP 5-HT2A receptors increased with 4-16% after PVC • Interregional differences of 5-HT2A density detected only after PVC • Estimates of influx and metabolism of 18F-DOPA altered in region specific manner after PVC
Study aims To estimate the influence of PVE on the measured regional uptake of [11C]FLB 457 • To evaluate the performance of different PVE correction • algorithms in PET studies with [11C]FLB 457: • Meltzer • Müller-Gärtner • Rousset
Image analysis • Image acquisition: • 6 subjects, T2w. MR, [11C]FLB 457 PET • Segmentation: • automated and manual • Coregistration: • manual, image overlay method (MARS) • PVE correction: • PVE developed within project QLG3-CT2000-00594 • ROI definition: • automated and manual
K1 k3 CF CB CP k2 k4 Quantification of ROI data Standard 3 compartment model BP = k3/k4 DV(tot) = (K1/k2)(1+k3/k4)
thalamus putamen caudate amygdala ROI mean (nCi/ml) parietal c. occipital c. temporal c. frontal c. white matter cerebellum time (min) [11C]FLB 457 uptake in the brain
thalamus putamen caudate amygdala parietal c. occipital c. temporal c. frontal c. white matter cerebellum [11C]FLB 457 uptake in the brain after PVE correction according to Meltzer ROI mean (nCi/ml) change in ROI mean (% of uncorrected values) time (min) time (min) * p < 0.05, * p < 0.005
thalamus putamen caudate amygdala parietal c. occipital c. temporal c. frontal c. white matter cerebellum [11C]FLB 457 uptake in the brain after PVE correction according to Müller-Gärtner ROI mean (nCi/ml) change in ROI mean (% of uncorrected values) time (min) time (min) * p < 0.05, * p < 0.005
thalamus putamen caudate amygdala parietal c. occipital c. temporal c. frontal c. white matter cerebellum [11C]FLB 457 uptake in the brain after PVE correction according to Rousset ROI mean (nCi/ml) change in ROI mean (% of uncorrected values) time (min) time (min) * p < 0.05, * p < 0.005
120.0 100.0 80.0 PET 25.0 Meltzer Müller-Gärtner 20.0 Rousset 15.0 10.0 5.0 0.0 Putamen Caudate Thalamus Amygdala Temp. c. Front. c. Pariet. c. Occipit. c. Total distribution volume (DV(tot)) VD(tot) * * * * * * * * * * * * * * * * * * * p < 0.05, * p < 0.005
PET Meltzer Müller-Gärtner Rousset Binding potential (BP) BP * * * * * * * * * p < 0.05, * p < 0.005
Conclusions • [11C]FLB 457 binding is underestimated to the highest degree in the temporal cortex and the amygdala. • DVtot is more susceptible to PVE than BP. • The applied PVE correction algorithms recovered the regional activity loss with different efficacy: • Meltzer: least efficient • Müller-Gärtner: increased DVtot and BP • Rousset: increased DVtot, enhanced differences in BP • (Comparison with receptor density obtained with in vitro methods?)