Table 1:

Pearson (r) and Spearman (ρ) correlations between rCBV metrics under PLD-corrected and non-PLD-corrected conditions, as measured by IBN and NICE perfusion software algorithms^{^a}

rCBV Metric	Non-PLD vs PLD (IBN)	P Value	Non-PLD vs PLD (NICE) with gvf	P Value	Non-PLD vs PLD (NICE) without gvf	P Value
Mean	r = 0.87	<.001	r = 0.11	.54	r = 0.43	.01
	ρ = 0.86	<.001	ρ = 0.42	.02	ρ = 0.62	<.001
Mode	r = 0.78	<.001	r = 0.44	.01	r = 0.51	.01
	ρ = 0.76	<.001	ρ = 0.65	<.001	ρ = 0.65	<.001
% < 1.75	r = 0.93	<.001	r = 0.55	<.001	r = 0.59	<.001
	ρ = 0.91	<.001	ρ = 0.61	<.001	ρ = 0.60	<.001
FTB	r = 0.96	<.001	r = 0.79	<.001	r = 0.70	<.001
	ρ = 0.94	<.001	ρ = 0.72	<.001	ρ = 0.71	<.001

Note:—gvf indicates γ variate fitting.
↵a NICE calculations were performed with and without gvf. IBN modeling shows substantially higher correlation between PLD and non-PLD metrics (compared with NICE), suggesting higher rCBV accuracy in the absence of PLD correction. Statistical significance is P value < .05.