Imaging D2-dopamine receptor concentration in non-human primate brain using 18F-fallypride

In this paper, we demonstrate how to form images of D2-dopamine receptor concentration in the brain with positron emission tomography (PET). Quantification of receptor sites within the brain is required to understand aging, diseases such as Alzheimer, and drug addiction. This quantification is performed by acquiring dynamic PET data and analyzing the tracer kinetics from the reconstructed emission data. The signal-to-noise ratio (SNR) of the reconstructed dynamic PET data is generally so low that region of interest (ROI) analysis is required to have accurate quantification. ROI analysis produces a single value of receptor concentration for each region in the brain. We recently show that it is possible to form parametric images directly from the acquired sinogram data [1]. Elimination of intermediate steps and direct reconstruction of parameters from sinograms allowed us to form dense images of parameters of interest. In this paper, we applied the direct parametric reconstruction algorithm to form images of D2-dopamine receptor concentration within monkey brain using ¹⁸F-fallypride radiotracer. Our initial investigations show that our D2 receptor images are consistent with the results of the classical ROI analysis.