Table 1.

Comparison of temporal standard deviations (SDs), contrast-to-noise ratios (CNR) and cross correlation coefficient (CCC) between inversion recovery continuous arterial spin labeling (IR-cASL) and continuous arterial spin labeling (cASL). For the hypercapnic challenge, the CNR was obtained from the whole-brain region of interest (ROI). For forepaw stimulation, CNR was obtained from 3×3 pixel ROIs of the primary somatosensory cortices

	Standard deviation
	whole brain	white matter	CO2 fMRI CNR	Forepaw fMRI CNR	Forepaw CCC
IR-cASL	0.32±0.04 a	0.45±0.02 b	6.3±1.0 c	6.3±2.8 d	0.47±0.07 e
cASL	0.57±0.11 a	0.90±0.19 b	3.2±0.5 c	2.8±2.3 d	0.30±0.10 e

^ap=0.01 (n=6)

^bp=0.0002 (n=6)

^cp=0.01 (n=5)

^dp=0.02 (n=4)

^ep=0.01 (n=4) for comparison between IR-cASL and cASL.