Discrimination between Alzheimer's Disease and Mild Cognitive Impairment Using SOM and PSO-SVM

Table 2

Statistical analysis of features.

Features	Mean volume ± SD
	Normal	MCI	AD	𝑃 value (NC versus MCI)	𝑃 value (NC versus AD)
Volume
𝑉GM	862.4 ± 42.7	824.6 ± 57.8	789.7 ± 84.3	0.016	0.007
𝑉WM	637.6 ± 45.8	601.8 ± 21.2	558.1 ± 63.4	0.021	0.019
𝑉CSF	863.1 ± 112.9	909.7 ± 128.5	971.8 ± 132.5	0.038	0.017
Shape
Area	1792.4 ± 278.5	1903.5 ± 426.6	2361.1 ± 802.3	0.029	0.024
Area (PR)	673.5 ± 121.5	874.9 ± 132.5	911.4 ± 183.2	0.024	0.018
Area (PL)	647.1 ± 137.2	872.5 ± 142.5	910.9 ± 183.5	0.031	0.011
Area (FR)	151.9 ± 117.6	231.5 ± 162.4	262.4 ± 167.8	0.020	0.009
Area (FL)	162.7 ± 91.0	258.2 ± 144.3	278.5 ± 189.2	0.022	0.010
Perimeter	226.7 ± 23.1	276.9 ± 20.2	289.8 ± 27.6	0.029	0.019
Circularity	45.6 ± 4.9	39.8 ± 3.6	38.2 ± 2.7	0.039	0.021
Elongation	1.1 ± 0.4	1.4 ± 0.6	1.3 ± 0.2	0.016	0.009
Rectangularity	0.5 ± 0.2	0.6 ± 0.4	0.6 ± 0.1	0.028	0.016
𝑑(A,G)	37.3 ± 2.1	38.4 ± 3.7	40.6 ± 4.2	0.031	0.037
𝑑(B,G)	36.1 ± 1.8	39.2 ± 3.1	43.1 ± 6.1	0.034	0.028
𝑑(C,G)	38.6 ± 4.3	41.4 ± 2.9	42.9 ± 4.6	0.042	0.030
𝑑(D,G)	34.7 ± 2.9	39.7 ± 1.4	42.8 ± 4.1	0.022	0.028
𝑑(A,C)	72.8 ± 4.3	81.7 ± 8.4	83.8 ± 8.4	0.009	0.011
𝑑(B,D)	72.5 ± 4.9	78.2 ± 3.1	81.6 ± 8.2	0.011	0.007
Min thickness	27.4 ± 3.8	29.0 ± 2.6	30.1 ± 3.4	0.020	0.009
Mean Sig.	25.6 ± 3.1	27.9 ± 2.7	29.8 ± 3.1	0.032	0.013