Average arterial input function for quantitative dynamic contrast enhanced magnetic resonance imaging of neck nodal metastases

Table 2 DCE-MRI Parameters K^trans and v_e calculated with Ind-AIF and Avg-AIF

AIF	Ind-AIF*	Avg-AIF*	Difference between Ind-AIF and Avg-AIF based parameter estimates
ROI K^trans (min^-1)	0.35 ± 0.29	0.23 ± 0.12	0.12 ± 0.08^a
Histogram Median K^trans (min^-1)	0.36 ± 0.29	0.22 ± 0.11	0.14 ± 0.09^b
ROI v_e	0.52 ± 0.51	0.43 ± 0.39	0.09 ± 0.06^c
Histogram Median v_e	0.37 ± 0.22	0.38 ± 0.19	0.01 ± 0.007^d

*Mean ± SD; Student's paired t-test for K^trans and v_e values obtained with Ind-AIF and Avg-AIF; Differences between Ind-and Avg-based parameter estimates: ^aP = 0.20, ^bP = 0.18, ^cP = 0.48, ^dP = 0.93.