A novel, fully automated, observer-independent program for semiquantifying striatal 123I-FP-CIT uptake

Abstract Objective To describe and validate a novel, fully automated program specifically designed for the semiquantification of striatal 123 I-FP-CIT uptake using volumes of interest (VOI) analysis. Material and methods The proposed algorithm is based on a template that mimics the striatal 123 I-FP-CIT uptake in a healthy subjects, derived from defined anatomical VOIs available from WFU PickAtlas. Four SPECT studies of the anthropomorphic Alderson phantom filled with variable radioactive concentrations were acquired for the experimental validation. Experimental SPECT images were spatially normalized with respect to the previously created template. The binary VOIs corresponding to left caudate and putamen and right caudate and putamen, which were used to construct the template, were projected onto the experimental images to obtain the counts for these regions. To minimize the partial volume effect, a percentage of the voxels in these regions (threshold), rather than all of them, was used. A binary occipital VOI was used to quantify the non-specific uptake. Experimental binding potentials (BPs) were calculated from the counts in these regions. True BPs were calculated from aliquots taken from the solutions used to fill the phantom. Results There were statistically significant differences in the experimental BP values ( p Conclusions Our novel, observer-independent program automatically performs the semiquantification of striatal 123 I-FP-CIT uptake in experimental studies.