Table 1.

Average segmentation performance over ten replicates evaluated using the Dice scores when segmenting low, medium, and high uptake simulated sphere regions from surrounding backgrounds. Standard deviation in parentheses

		Dice scores
Segmentation region	Voxel representation	Hierarchical clustering	Spectral clustering	K-means clustering	Rad-FIT clustering
Low uptake sphere	Time activity curves	0.15 (0)	0.04 (0.001)	0.13 (0.06)	0.24 (0.07)
	FPC	0.67 (0)	0.16 (0.03)	0.65 (0.02)	0.70 (0.01)
Medium uptake sphere	Time activity curves	0.77 (< 0.001)	0.06 (0.01)	0.44 (0.4)	0.73 (< .001)
	FPC	0.78 (0)	0.20 (0.18)	0.84 (0.03)	0.85 (0)
High uptake sphere	Time activity curves	0.72 (0)	0.18 (0.07)	0.52 (0.40)	0.66 (0)
	FPC	0.83 (0)	0.17 (0.03)	0.84 (0)	0.86 (0)