Results of multiple regression analysis, revealing no significant difference between scenario1 and 2.

Therefore, decision was made to use scenario 2 in the further analysis because of fewer explanatory variables. Scenario 1; explanatory variables include ln(age), A, B, D, AA, BB and DD, Scenario 2; explanatory variables include ln(age), A, B, D and EE, n; case number, R; correlation coefficient, R2; coefficient of determination, SE; standard error, A: Maximum distance between anterior horn, B: Minimum bicaudate nuclei distance, D: Third ventricle distance, AA, BB and DD: corresponding brain width to maximum distance between anterior horn, minimum bicaudate nuclei distance, third ventricle distance, respectively, EE: a square root of summation for AA2, BB2, and DD2.