Echogenicity and size of substantia nigra on transcranial sonography (TCS) in patients with attention-deficit/hyperactivity disorder and healthy children aged 6–12 years: a comparative study

Table 4 Comparison of perimeter and area substantia nigra nucleus in two groups, using linear regression model

Model		Unstandardized coefficients		Standardized coefficients	Sig.
Model		B	Std. Error	Beta	Sig.
A	Group	0.036	0.045	0.108	0.424
A	Age	0.013	0.011	0.151	0.266
B	Group	0.046	0.036	0.173	0.200
B	Age	0.009	0.009	0.139	0.302
C	Group	0.079	0.111	0.096	0.479
C	Age	0.030	0.028	0.146	0.281

Sig. significance
For parameter estimating (beta) ordinary least square (OLS) method was used and for determining significancy t test was applied