Table 4.

The coefficient of joint variation (cjv) between gray matter (GM) and white matter (WM) of T1-weighted human brain data set. Smaller cjv value represents increased tissue contrast between GM and WM. On average, both our new algorithm and N3 resulted in significantly reduced cjv compared to source data.

Set	cjv(GM,WM) (%)
	Source	UNI	SPM	BSU	N3	New Sagittal	New Axial	New Coronal
1	78.0	76.7	72.1	67.5	60.2	66.0	61.7	67.3
2	80.7	80.0	87.1†	72.3	69.2	71.1	61.9	70.4
3	75.7	75.7	73.5	94.6†	55.8	59.0	52.9	60.6
4	92.3	107.8†	90.8	120.8†	82.3	89.5	81.1	90.3
5	78.2	78.5†	79.3†	90.4†	59.5	64.2	58.1	60.4
6	73.2	83.5†	74.1†	92.3†	61.0	65.9	61.6	66.1
7	71.0	82.7†	75.9†	71.4†	53.4	63.6	58.6	64.7
8	74.6	86.3†	77.1†	118.2†	54.3	63.6	63.2	63.1

BSU = BrainSuite, New = the algorithm presented in this study, N3 = nonparametric nonuniform intensity normalization, SPM = statistical parametric mapping, UNI = uniform correction program,

^†cjv values of bias-corrected data greater than those of source data.