Effects of rigid and non-rigid image registration on test-retest variability of quantitative [18F]FDG PET/CT studies

EJNMMI Research

Table 2 Median Dice similarity coefficients (DSC) for various registration strategies and similarity measures

Transformation	Input data	Program	Similarity measure
			SSD	NCC	MI
Rigid	PET	Elastix	0.74	0.71	0.68
		RegisRigid	0.65	0.59	0.54
	NAC	Elastix	0.59	0.59	0.56
		RegisRigid	0.59	0.60	0.60
	CT	Elastix	0.71	0.71	0.72
		RegisRigid	0.72	0.72	0.71
Non-rigid	PET	Elastix	0.81	0.82	0.71
		splineMIRIT	0.77	0.78	0.77
	NAC	Elastix	0.69	0.72	0.21
		splineMIRIT	0.66	0.73	0.74
	CT	Elastix	0.68	0.67	0.68
		splineMIRIT	0.59	0.60	0.68
	CTPET	Elastix	0.82	0.82	0.69
		splineMIRIT	0.77	0.78	-^a

^aThe program was not able to obtain registrations due to memory issues; SSD = summed squared differences; NCC = normalized cross correlation; MI= mutual information