Table 2.

Summary of the quantitative analysis of the biophysical characteristics and tract volumes of the delineated HMFTs. Note the increase in the coefficient of variation compared to the CST measurements. This indicates a much higher variability of the results among our healthy subjects (>10%), possibly due to the limitations of the currently available imaging tools, leading to outliers. In agreement with the CST quantitative measurements database, the tract volume was found once again to be much more variable among the subjects (coefficient of variation approximately 53%). Note that 12.7%, SD=5.7, of the CSTs analyzed refers to the hand motor area. This measurement was based on the normalized volumes of the respective tracts.

	FA	RD	AD	Tract Volume (cm3)	Normalized Tract Volume (cm3)	(HMFT/CST) *100 (%)	Length (mm)
HMFT	Mean	Mean	Mean	Mean	Mean	Mean	Mean
	0.67328	292.48218	1206.34166	2.77043	0.00183	12.71336	145.78101
	SD	SD	SD	SD	SD	SD	SD
	0.12130	40.23243	193.59313	1.38335	0.00093	5.74696	5.09166
	CV	CV	CV	CV	CV	CV	CV
	0.18017	0.13756	0.16048	0.49933	0.50588	0.45204	0.03493
Left HMFT	Mean	Mean	Mean	Mean	Mean	Mean	Mean
	0.60053	249.82454	1057.31801	1.25538	0.00083	10.98581	125.22519
	SD	SD	SD	SD	SD	SD	SD
	0.24648	104.96879	439.95864	1.00055	0.00066	9.04304	51.26034
	CV	CV	CV	CV	CV	CV	CV
	0.41044	0.42017	0.41611	0.79701	0.80137	0.82316	0.40935
Right HMFT	Mean	Mean	Mean	Mean	Mean	Mean	Mean
	0.68688	275.72408	1232.85584	1.54424	0.00103	14.47254	142.48962
	SD	SD	SD	SD	SD	SD	SD
	0.12130	53.30109	225.78500	0.88224	0.00060	7.31332	25.23457
	CV	CV	CV	CV	CV	CV	CV
	0.17660	0.19331	0.18314	0.57131	0.59003	0.50532	0.17710
SI HMFT	Mean	Mean	Mean	Mean	Mean	Mean	Mean
	−0.13415	−0.09856	−0.15330	−0.20636	−0.21596	−0.27392	−0.12898
	SD	SD	SD	SD	SD	SD	SD
	0.68072	0.65291	0.64341	0.12567	0.08928	0.21150	0.68046

Abbreviations used: CST: corticospinal tract, FA: fractional anisotropy, RD: radial diffusivity, AD: axial diffusivity, SD: standard deviation, CV: coefficient of variation, SI: symmetry index.