Table 3.

Multi-linear regression analysis of C2-C3 TCA and GMA.

TCA	V-scale	axial_canal_product	sex	%RSD	%RSDmeas
Model1	−24.15	-	-	8.50% (10.24%)	9.47%
Model2	-	0.0807	3.1936	8.00% (15.52%)
Model3	−16.76	0.0715	-	7.79% (17.74%)
GMA	V-scale	axial_canal_product	sex	%RSD	%RSDmeas
Model1	−7.00	-	-	11.63% (8.28%)	12.68%
Model2	-	0.0214	1.1025	11.14% (12.15%)
Model3	−5.03	0.0191	-	11.02% (13.09%)

Normalization coefficients derived by multi-linear regression analysis with C2-C3 total cross-sectional area (TCA, top) and C2-C3 gray matter area (GMA, bottom) as outcome variables and sex, V-scale and axial_canal_product as independent variables (see Eq.1 in the text). The %RSD (ratios of the group standard deviation and the respective means) for the calculated values with each model are reported. %RSDmeas refers to the non-normalized measured data. In the second last column, in parenthesis, the relative %RSD reduction obtained going from measured to normalized data is reported (in percentage) for each model.

Mean values of the independent variables on the total cohort of subjects:

Xmean = V-scale_mean = 1.346

Ymean = axial_canal_product_mean = 261.16 mm²