Supplement WAPI approach
MATERIALS AND METHODS
The experimental and analyticalprocedures were the same as described in the main manuscript, with the exception that the regionalBPNDwas derived from parametric images using the Wavelet Aided Parametric Imaging(WAPI) approach described in the literature [1]. Shortly, BPND in each voxel was determined by means of Logan graphical analysis, using cerebellum as the reference region. The mean BPNDvalue of all voxels in each ROI was then calculated and entered into the test-retest analysis. With this method, noise is reduced and the signal from each region gets smoothed compared to the conventional ROI-based compartmental analysis.
RESULTS
Binding potential, BPND
Individual BPND values ranged from 0.41 to 2.28. As with the traditional ROI-based method, the mean regional BPNDwas highest in OCC (1.97±0.21 and 1.94±0.19) and lowest in THAL (0.57±0.09 and 0.56±0.08). The individual and mean BPND in each region at PET 1 and PET 2 are given in table 1 suppl.
Difference between BPND at PET 1 and PET 2
As with the traditional ROI-based approach, the absolute mean difference in regional BPND was less than 3 % in all regions except the RN. The absolute variability was similar to that achieved with the traditional method. The variability and difference are given in table 1 suppl and illustrated in fig 1 suppl.
Moreover, using the WAPI approach, similar BPND values were obtained at PET 1 and PET 2 in the projection areas (fig 2 suppl).
ICC
The ICC was highest in occipital cortex (0.83). ICC for frontal and temporal cortex was substantially lower – 0.22 and 0.37 respectively. ICC for subcortical projection areas were 0.48 and 0.69 respectively (table 1 suppl).
1.Cselenyi Z, Olsson H, Farde L, Gulyas B. Wavelet-aided parametric mapping of cerebral dopamine D2 receptors using the high affinity PET radioligand [11C]FLB 457. Neuroimage. 2002;17:47-60.
Figure legends:
Fig. 1 supplIndividual BPND values derived with the WAPI method at PET 1 and PET 2. a) Frontal cortex, b) Occipital cortex , c) Temporal cortex, d) Putamen, e) Thalamus, f) Raphe Nuclei
Fig. 2 suppl Relationship between individual BPNDvalues derived with the WAPI method at PET 1 and PET 2 in serotonergic projection areas. Each dot represents the value at PET 1 (x-axis) and PET 2 (y-axis) for one particular subject in one of the five regions. The solid line represents the line of identity for the BPND at PET 1 and PET 2