Striatal dopamine transporter and receptor availability correlate with relative cerebral blood flow measured with [11C]PE2I, [18F]FE-PE2I and [11C]raclopride PET in healthy individuals

The aim of this retrospective study was to investigate relationships between relative cerebral blood flow and striatal dopamine transporter and dopamine D2/3 availability in healthy subjects. The data comprised dynamic PET scans with two dopamine transporter tracers [C-11]PE2I (n = 20) and [F-18]FE-PE2I (n = 20) and the D2/3 tracer [C-11]raclopride (n = 18). Subjects with a [C-11]PE2I scan also underwent a dynamic scan with the serotonin transporter tracer [C-11]DASB. Binding potential (BPND) and relative tracer delivery (R-1) values were calculated on regional and voxel-level. Striatal R-1 and BPND values were correlated, using either an MRI-based volume of interest (VOI) or an isocontour VOI based on the parametric BPND image. An inter-tracer comparison between [C-11]PE2I BPND and [C-11]DASB R-1 was done on a VOI-level and simulations were performed to investigate whether the constraints of the modeling could cause correlation of the parameters. A positive association was found between BPND and R-1 for all three dopamine tracers. A similar correlation was found for the inter-tracer correlation between [C-11]PE2I BPND and [C-11]DASB R-1. Simulations showed that this relationship was not caused by cross-correlation between parameters in the kinetic model. In conclusion, these results suggest an association between resting-state striatal dopamine function and relative blood flow in healthy subjects.

Automated summary

The aim of this retrospective study was to investigate the relationships between relative cerebral blood flow and striatal dopamine transporter and dopamine D2/3 availability in healthy subjects. The data included dynamic PET scans with two dopamine transporter tracers [C-11]PE2I and [F-18]FE-PE2I, and the D2/3 tracer [C-11]raclopride. The results suggest that there is an association between resting-state striatal dopamine function and relative blood flow in healthy subjects.