Table 2:

General linear regression of SNR in CBV, CBF, and MTT values among different tube currents, locations, reconstructive algorithms, and peak arterial and venous enhancement

	SNR of CBF		SNR of CBV		SNR of MTT
	Standardized Estimate	P Value	Standardized Estimate	P Value	Standardized Estimate	P Value
80 mAs^{^a}	0.043	.412	0.016	.747	−0.121	.031^{^d}
IR reconstruction^{^b}	−0.008	.872	0.002	.655	0.007	.887
Gray matter^{^c}	0.443	<.001^{^d}	0.515	<.001^{^d}	−0.203	<.001^{^d}
Peak enhancement of arterial ROI	0.055	.286	0.064	.195	−.178	.001^{^d}
Peak enhancement of venous ROI	0.017	.754	0.043	.408	−0.163	.005^{^d}

↵a The control group has a tube current of 100 mAs.
↵b The control group is processed by FBP.
↵c The control group is ROI white matter, including ROI1 and ROI5; the experimental group is ROI gray matter including ROI2, ROI3, and ROI4.
↵d Statistically significant (P < .05).